Metaphysics is a branch of philosophy concerned with explaining the fundamental nature of being and the world, although the term is not easily defined. Traditionally, metaphysics attempts to answer two basic questions in the broadest possible terms: # "What ''is there''?" # "What is it [...] ''like''?"

A person who studies metaphysics would be called either a ''metaphysicist'' or a ''metaphysician''. The metaphysician attempts to clarify the fundamental notions by which people understand the world, including existence, the definition of object, property, space, time, causality, and possibility.

A central branch of metaphysics is ontology, the investigation into the basic categories of being and how they relate to each other.

Prior to the modern history of science, scientific questions were addressed as a part of metaphysics known as natural philosophy. The term ''science'' itself meant "knowledge" of, originating from epistemology. The scientific method, however, transformed natural philosophy into an empirical activity deriving from experiment unlike the rest of philosophy. By the end of the 18th century, it had begun to be called "science" to distinguish it from philosophy. Thereafter, metaphysics denoted philosophical enquiry of a non-empirical character into the nature of existence.

Etymology

The word "metaphysics" derives from the Greek words ''μετά (metá)'' ("beyond" or "after") and ''φυσικά (physiká)'' ("physics"). It was first used as the title for several of Aristotle's works, because they were usually anthologized after the works on physics in complete editions. The prefix ''meta-'' ("beyond") indicates that these works come "after" the chapters on physics. However, Aristotle himself did not call the subject of these books "Metaphysics": he referred to it as "first philosophy." The editor of Aristotle's works, Andronicus of Rhodes, is thought to have placed the books on first philosophy right after another work, ''Physics'', and called them (''ta meta ta physika biblia'') or "the books that come after the [books on] physics". This was misread by Latin scholiasts, who thought it meant "the science of what is beyond the physical".

However, once the name was given, the commentators sought to find intrinsic reasons for its appropriateness. For instance, it was understood to mean "the science of the world beyond nature (''phusis'' in Greek)," that is, the science of the immaterial. Again, it was understood to refer to the chronological or pedagogical order among our philosophical studies, so that the "metaphysical sciences would mean, those that we study after having mastered the sciences that deal with the physical world" (St. Thomas Aquinas, "In Lib, Boeth. de Trin.", V, 1).

There is a widespread use of the term in current popular literature, which replicates this error, i.e. that metaphysical means spiritual non-physical: thus, "metaphysical healing" means healing by means of remedies that are not physical.''

Origins and nature of metaphysics

Although the ''word'' "metaphysics" goes back to Aristotelean philosophy, Aristotle himself credited earlier philosophers with dealing with metaphysical questions. The first known philosopher, according to Aristotle, is Thales of Miletus, who taught that all things derive from a single first cause or ''Arche''.

Scientific questions in ancient Greece were addressed to metaphysicians, but by the 18th century, the skeptics' ''How do you know?'' led to a new branch of philosophy called ''epistemology'' (''how'' we know) to fill-out the metaphysics (''what'' we know) and this led to science (Latin ''to know'') and to the scientific method (the precision of which is still being debated). Skepticism evolved epistemology out of metaphysics. Thereafter, metaphysics denoted philosophical inquiry of a non-empirical character into the nature of existence.

Metaphysics as a discipline was a central part of academic inquiry and scholarly education even before the age of Aristotle, who considered it "the Queen of Sciences." Its issues were considered no less important than the other main formal subjects of physical science, medicine, mathematics, poetics and music. Since the beginning of modern philosophy during the seventeenth century, problems that were not originally considered within the bounds of metaphysics have been added to its purview, while other problems considered metaphysical for centuries are now typically subjects of their own separate regions in philosophy, such as philosophy of religion, philosophy of mind, philosophy of perception, philosophy of language, and philosophy of science.

In some cases, subjects of metaphysical scholarship have been found to be entirely physical and natural, thus making them part of science proper (cf. the theory of Relativity).

Aristotle's branching

Aristotle's ''Metaphysics'' was divided into three parts, which are now regarded as the proper branches of traditional Western metaphysics:

; ''Ontology'' : The study of being and existence; includes the definition and classification of entities, physical or mental, the nature of their properties, and the nature of change.

; ''Natural Theology'' : The study of a God or Gods; involves many topics, including among others the nature of religion and the world, existence of the divine, questions about Creation, and the numerous religious or spiritual issues that concern humankind in general.

; ''Universal science'' : The study of first principles, which Aristotle believed were the foundation of all other inquiries. An example of such a principle is the law of noncontradiction and the status it holds in non-paraconsistent logics.

Universal science or first philosophy treats of "being qua being"—that is, what is basic to all science before one adds the particular details of any one science. Essentially "being ''qua'' being" may be translated as "being insofar as being goes" or as "being in terms of being." This includes topics such as causality, substance, species and elements, as well as the notions of relation, interaction, and finitude.

Central questions

Most positions that can be taken with regards to any of the following questions are endorsed by one or another notable philosopher. It is often difficult to frame the questions in a non-controversial manner.

Being, existence and reality

The nature of Being is a perennial topic in metaphysics. For, instance Parmenides taught that reality was a single unchanging Being. The 20th century philosopher Heidegger thought previous philosophers have lost sight the question of Being (qua Being) in favour of the questions of beings (existing things), so that a return to the Parmenidean approach was needed. An ontological catalogue is an attempt to list the fundamental constituents of reality. The question of whether or not existence is a predicate has been discussed since the Early Modern period, not least in relation to the ontological argument for the existence of God. Existence, ''that'' something is, has been contrasted with ''essence'', the question of ''what'' something is. Since existence without essence seems blank, it associated with nothingness by philosophers such as Hegel. Nihilism represents an extremely negative view of being, the Absolute a positive one.

Empirical and conceptual objects

Objects and their properties

The world seems to contain many individual things, both physical, like apples, and abstract such as love and the number 3; the former objects are called particulars. Particulars are said to have attributes, e.g. size, shape, color, location and two particulars may have some such attributes in common. Such attributes, are also termed Universals or Properties; the nature of these, and whether they have any real existence and if so of what kind, is a long-standing issue, realism and nominalism representing opposing views.

Metaphysicians concerned with questions about universals or particulars are interested in the nature of objects and their properties, and the relationship between the two. Some, e.g. Plato, argue that properties are abstract objects, existing outside of space and time, to which particular objects bear special relations. David Armstrong holds that universals exist in time and space but only at their instantiation and their discovery is a function of science. Others maintain that particulars are a bundle or collection of properties (specifically, a bundle of properties they have).

Abstract objects and mathematics

Some philosophers endorse views according to which there are abstract objects such as numbers, or Universals. (Universals are properties that can be instantiated by multiple objects, such as redness or squareness.) Abstract objects are generally regarded as being outside of space and time, and/or as being causally inert. Mathematical objects and fictional entities and worlds are often given as examples of abstract objects. The view that there really are no abstract objects is called nominalism. Realism about such objects is exemplified by Platonism. Other positions include moderate realism, as espoused by Aristotle, and conceptualism.

The philosophy of mathematics overlaps with metaphysics because some positions are realistic in the sense that they hold that mathematical objects really exist, whether transcendentally, physically, or mentally. Platonic realism holds that mathematical entities are a transcendent realm of non-physical objects. The simplest form of mathematical empiricism claims that mathematical objects are just ordinary physical objects, i.e. that squares and the like physically exist. Plato rejected this view, among other reasons, because geometrical figures in mathematics have a perfection that no physical instantiation can capture. Modern mathematicians have developed many strange and complex mathematical structures with no counterparts in observable reality, further undermining this view. The third main form of realism holds that mathematical entities exist in the mind. However, given a materialistic conception of the mind, it does not have the capacity to literally contain the many infinities of objects in mathematics. Intuitionism, inspired by Kant, sticks with the idea that "there are no non-experienced mathematical truths". This involves rejecting as intuitionistically unacceptable anything that cannot be held in the mind or explicitly constructed. Intuitionists reject the law of the excluded middle and are suspicious of infinity, particularly of transfinite numbers.

Other positions such as formalism and fictionalism that do not attribute any existence to mathematical entities are anti-realist.

Cosmology and cosmogony

Metaphysical Cosmology is the branch of metaphysics that deals with the world as the totality of all phenomena in space and time. Historically, it has had quite a broad scope, and in many cases was founded in religion. The ancient Greeks did not draw a distinction between this use and their model for the cosmos. However, in modern times it addresses questions about the Universe beyond the scope of physical science. It is distinguished from religious cosmology in that it approaches these questions using philosophical methods (e.g. dialectics). Cosmogony deals specifically with the origin of the universe.

Modern metaphysical cosmology and cosmogony try to address questions such as:

What is the origin of the Universe? What is its first cause? Is its existence necessary? (see monism, pantheism, emanationism and creationism)

What are the ultimate material components of the Universe? (see mechanism, dynamism, hylomorphism, atomism)

What is the ultimate reason for the existence of the Universe? Does the cosmos have a purpose? (see teleology)

Determinism and free will

Determinism is the philosophical proposition that every event, including human cognition, decision and action, is causally determined by an unbroken chain of prior occurrences. It holds that no random, spontaneous, stochastic, mysterious, or miraculous events occur. The principal consequence of the deterministic claim is that it poses a challenge to the existence of free will.

The problem of free will is the problem of whether rational agents exercise control over their own actions and decisions. Addressing this problem requires understanding the relation between freedom and causation, and determining whether the laws of nature are causally deterministic. Some philosophers, known as Incompatibilists, view determinism and free will as mutually exclusive. If they believe in determinism, they will therefore believe free will to be an illusion, a position known as ''Hard Determinism''. Proponents range from Baruch Spinoza to Ted Honderich.

Others, labeled Compatibilists (or "Soft Determinists"), believe that the two ideas can be coherently reconciled. Adherents of this view include Thomas Hobbes and many modern philosophers.

Incompatibilists who accept free will but reject determinism are called Libertarians, a term not to be confused with the political sense. Robert Kane is a modern defender of this theory.

It is believed that determinism necessarily entails that humanity or individual humans have no influence on the future and its events (a position known as Fatalism). Determinists believe a human being's future depends on present and past events beyond the individual's influence.

Quantum physics

Proponents of the Copenhagen Interpretation of quantum mechanics believe that Determinism was proven incorrect with the Heisenberg Uncertainty Principle, which states that certain corresponding physical quantities (such as position and momentum, energy and time, eigenstates of spin in non-parallel directions) cannot be determined simultaneously to an arbitrarily small error. For example, the more precisely a particle's position is measured, the less precisely one can know its momentum from the same measurement. If the momentum is more precisely measured to account for this, the uncertainty in the position will rise. This counter-intuitive result is a consequence of the wave-like behavior of subatomic particles. The Heisenberg Uncertainty Principle is thus a statement providing an inverse correlation between the uncertainties of certain corresponding measurements.

This result has led physicists to develop Quantum field theory and use the "wave function" to describe physical systems. While differential equations govern the evolution of the wave function, the wave function itself only specifies the probability of an event to be measured. Thus, while the evolution of the wave function is deterministic, the history of a particle is not. The widely held view amongst physicists regards the apparent determinism of Newtonian dynamics, for example, as the limiting behavior of inherently probabilistic phenomena. Classical physics is then considered a convenient and sufficiently accurate description of nature only at macroscopic scales. A large enough scale is usually thought of as much larger than the Compton wavelength of the object considered.

Alternative interpretations of quantum theory, such as de Broglie–Bohm theory and the many-worlds interpretation, provide a deterministic theoretical framework that is consistent with empirical observation of quantum mechanical phenomena. Notable physicists, such as Albert Einstein and Erwin Schrödinger, never believed that Quantum Mechanics was a fundamental theory. Einstein is famous for believing that while Quantum Mechanics provided good experimental predictions, it should ultimately be replaced with a deterministic theory that could account for the seemingly probabilistic nature of the atomic regime. In a letter to Max Born, Einstein wrote, "Quantum mechanics is certainly imposing. But an inner voice tells me that it is not yet the real thing. The theory says a lot, but does not really bring us any closer to the secret of the 'old one'. I, at any rate, am convinced that ''He'' does not throw dice." This quote is commonly paraphrased "God does not play dice" or "God does not play dice with the universe", and other slight variants.

Though there remains skepticism, there is a scientific consensus that the laws of Quantum Mechanics correctly describe the universe up to current experimental bounds, and that it is necessary for the very consistency of the subject that our observations be probabilistic in nature (see Bell's Theorem).

Identity and change

The Greeks took some extreme positions on the nature of change: Parmenides denied that change occurs at all, while Heraclitus thought change was ubiquitous: "[Y]ou cannot step into the same river twice".

Identity, sometimes called Numerical Identity, is the relation that a "thing" bears to itself, and which no "thing" bears to anything other than itself (cf. sameness). According to Leibniz, if some object ''x'' is identical to some object ''y'', then any property that ''x'' has, ''y'' will have as well. However, it seems, too, that objects can change over time. If one were to look at a tree one day, and the tree later lost a leaf, it would seem that one could still be looking at that same tree. Two rival theories to account for the relationship between change and identity are Perdurantism, which treats the tree as a series of tree-stages, and Endurantism, which maintains that the tree—the same tree—is present at every stage in its history.

Mind and matter

The nature of matter was a problem in its own right in early philosophy. Aristotle himself introduced the idea of matter in general to the Western world, adapting the term ''hyle'', which originally meant "lumber." Early debates centered on identifying a single underlying principle. Water was claimed by Thales, air by Anaximenes, ''Apeiron'' (the Boundless) by Anaximander, fire by Heraclitus. Democritus, in conjunction with his mentor, Leucippus, conceived of an atomic theory many centuries before it was accepted by modern science. It is worth noting, however, that the grounds necessary to ensure validity to the proposed theory's veridical nature were not scientific, but just as philosophical as those traditions espoused by Thales and Anaximander.

The nature of the mind and its relation to the body has been seen as more of a problem as science has progressed in its mechanistic understanding of the brain and body. Proposed solutions often have ramifications about the nature of mind as a whole. René Descartes proposed substance dualism, a theory in which mind and body are essentially different, with the mind having some of the attributes traditionally assigned to the soul, in the seventeenth century. This creates a conceptual puzzle about how the two interact (which has received some strange answers, such as occasionalism). Evidence of a close relationship between brain and mind, such as the Phineas Gage case, have made this form of dualism increasingly unpopular.

Another proposal discussing the mind-body problem is idealism, in which the material is sweepingly eliminated in favor of the mental. Idealists, such as George Berkeley, claim that material objects do not exist unless perceived and only as perceptions. The "German idealists" such as Fichte, Hegel and Schopenhauer took Kant as their starting-point, although it is debatable how much of an idealist Kant himself was. Idealism is also a common theme in Eastern philosophy. Related ideas are panpsychism and panexperientialism, which say everything ''has'' a mind rather than everything exists ''in'' a mind. Alfred North Whitehead was a twentieth-century exponent of this approach.

Idealism is a monistic theory that holds there is a single universal substance or principles. Neutral monism, associated in different forms with Baruch Spinoza and Bertrand Russell, seeks to be less extreme than idealism, and to avoid the problems of substance dualism. It claims that existence consists of a single substance that in itself is neither mental nor physical, but is capable of mental and physical aspects or attributes thus it implies a dual-aspect theory.

For the last one hundred years, the dominant metaphysics has without a doubt been materialistic monism. Type identity theory, token identity theory, functionalism, reductive physicalism, nonreductive physicalism, eliminative materialism, anomalous monism, property dualism, epiphenomenalism and emergence are just some of the candidates for a scientifically informed account of the mind. (It should be noted that while many of these positions are dualisms, none of them are ''substance'' dualism.)

Prominent recent philosophers of mind include David Armstrong, Ned Block, David Chalmers, Patricia and Paul Churchland, Donald Davidson, Daniel Dennett, Douglas Hofstadter, Jerry Fodor, David Lewis, Thomas Nagel, Hilary Putnam, John Searle, John Smart, Ludwig Wittgenstein, and Fred Alan Wolf.

Necessity and possibility

Metaphysicians investigate questions about the ways the world could have been. David Lewis, in "On the Plurality of Worlds," endorsed a view called Concrete Modal realism, according to which facts about how things could have been are made true by other concrete worlds, just like ours, in which things are different. Other philosophers, such as Gottfried Leibniz, have dealt with the idea of possible worlds as well. The idea of necessity is that any necessary fact is true across all possible worlds; that is, we could not imagine it to be otherwise. A possible fact is true in some possible world, even if not in the actual world. For example, it is possible that cats could have had two tails, or that any particular apple could have not existed. By contrast, certain propositions seem necessarily true, such as analytic propositions, e.g. "All bachelors are unmarried." The particular example of analytic truth being necessary is not universally held among philosophers. A less controversial view might be that self-identity is necessary, as it seems fundamentally incoherent to claim that for any ''x'', it is not identical to itself; this is known as the ''law of identity'', a putative "first principle". Aristotle describes the ''principle of non-contradiction'', "It is impossible that the same quality should both belong and not belong to the same thing . . . This is the most certain of all principles . . . Wherefore they who demonstrate refer to this as an ultimate opinion. For it is by nature the source of all the other axioms."

Religion and spirituality

Theology is the study of a God or gods and the nature of the divine. Whether there is a god (monotheism), many gods (polytheism) or no gods (atheism), or whether it is unknown or unknowable whether any gods exist (agnosticism), and whether the Divine intervenes directly in the world (theism), or its sole function is to be the first cause of the universe (deism); these and whether a God or gods and the World are different (as in panentheism and dualism), or are identical (as in pantheism), are some of the primary metaphysical questions concerning philosophy of religion.

Within the standard Western philosophical tradition, theology reached its peak under the medieval school of thought known as scholasticism, which focused primarily on the metaphysical aspects of Christianity. The work of the scholastics is still an integral part of modern philosophy, with key figures such as Thomas Aquinas still playing an important role in the philosophy of religion.

Space and time

In Book XI of the Confessions, Saint Augustine of Hippo asked the fundamental question about the nature of time. A traditional realist position in ontology is that time and space have existence apart from the human mind. Idealists, including Kant, claim that space and time are mental constructs used to organize perceptions, or are otherwise surreal.

Suppose that one is sitting at a table, with an apple in front of him or her; the apple exists in space and in time, but what does this statement indicate? Could it be said, for example, that space is like an invisible three-dimensional grid in which the apple is positioned? Suppose the apple, and all physical objects in the universe, were removed from existence entirely. Would space as an "invisible grid" still exist? René Descartes and Leibniz believed it would not, arguing that without physical objects, "space" would be meaningless because space is the framework upon which we understand how physical objects are related to each other. Newton, on the other hand, argued for an absolute "container" space. The pendulum swung back to relational space with Einstein and Ernst Mach.

While the absolute/relative debate, and the realism debate are equally applicable to time and space, time presents some special problems of its own. The ''flow'' of time has been denied in ancient times by Parmenides and more recently by J. M. E. McTaggart in his paper ''The Unreality of Time''.

The ''direction'' of time, also known as "time's arrow", is also a puzzle, although physics is now driving the debate rather than philosophy. It appears that fundamental laws are time-reversible and the arrow of time must be an "emergent" phenomenon, perhaps explained by a statistical understanding of thermodynamic entropy.

Common-sense tells us that objects ''persist'' across time, that there is some sense in which you are the same person you were yesterday, in which the oak is the same as the acorn, in which you perhaps even can step into the same river twice. Philosophers have developed two rival theories for how this happens, called "endurantism" and "perdurantism". Broadly speaking, endurantists hold that a whole object exists at each moment of its history, and the same object exists at each moment. Perdurantists believe that objects are four-dimensional entities made up of a series of temporal parts like the frames of a movie.

Styles and methods of metaphysics

Rational versus empirical. Rationalism is a method or a theory "in which the criterion of the truth is not sensory but intellectual and deductive" (Bourke 263). Rationalist metaphysicians aim to deduce the nature of reality by armchair, apriori reasoning. Empiricism holds that the senses are the primary source of knowledge about the world.

Analytical versus systemic. The "system building" style of metaphysics attempts to answer ''all'' the important questions in a comprehensive and coherent way, providing a theory of everything or complete picture of the world. The contrasting approach is to deal with problems piecemeal.

Dogmatic versus critical. Under the scholastic approach of the Middle Ages, a number of themes and ideas were not open to be challenged. Kant and others thought this "dogmatism" should be replaced by a critical approach.

Individual versus collective. Scholasticism and Analytical philosophy are examples of collaborative approaches to philosophy. Many other philosophers expounded individual visions.

Parsimonious versus Adequate. Should a metaphysical system posit as little as possible, or as much as needed?

Descriptive versus revisionary. Peter Strawson makes the distinction between descriptive metaphysics, which sets out to investigate our deepest assumptions, and revisionary metaphysics, which sets out to improve or rectify them.

History and schools of metaphysics

Pre-Socratic metaphysics in Greece

The first known philosopher, according to Aristotle, is Thales of Miletus. Rejecting mythological and divine explanations, he sought for a single first cause or ''Arche'' (origin or beginning) under which all phenomena could be explained, and concluded that this first cause was in fact moisture or water. Thales also taught that the world is harmonious, has a harmonious structure, and thus is intelligible to rational understanding. Other Miletians, such as Anaximander and Anaximenes, also had a monistic conception of the first cause.

Another school was the Eleatics, Italy. The group was founded in the early fifth century BCE by Parmenides, and included Zeno of Elea and Melissus of Samos. Methodologically, the Eleatics were broadly rationalist, rejecting the epistemological validity of sense experience, and instead took logical standards of clarity and necessity to be the criteria of truth. Parmenides' chief doctrine was that reality is a single unchanging and universal Being. Zeno used ''reductio ad absurdum'', to demonstrate the illusory nature of change and time in his paradoxes.

Heraclitus of Ephesus, in contrast, made change central, teaching that "all things flow". His philosophy, expressed in brief aphorisms, is quite cryptic. For instance, he also taught the unity of opposites.

Democritus and his teacher Leucippus, are known for formulating an atomic theory for the cosmos. They are considered forerunners of the scientific method.

Socrates and Plato

Socrates is known for his dialectic or questioning approach to philosophy rather than a positive metaphysical doctrine. His pupil, Plato is famous for his theory of forms (which he confusingly places in the mouth of Socrates in the dialogues he wrote to expound it). Platonic realism (also considered a form of idealism) is principally a solution to the problem of universals; what particular horses have in common is that they partake in the Form of the Horse. The theory has a number of other aspects:

Epistemological: knowledge of the Forms is more certain than mere sensory data.

Ethical. The Form of the Good sets an objective standard for morality.

Time and Change: The world of the Forms is eternal and unchanging. Time and change belong only to the lower sensory world. "Time is a moving image of Eternity".

Abstract objects and mathematics: Numbers, geometrical figures, etc., exist mind-independently in the World of Forms.

Platonism developed into Neoplatonism, a philosophy with a monotheistic and mystical flavour that survived well into the early Christian era.

Aristotle

Plato's pupil Aristotle wrote widely on almost every subject, including metaphysics. His solution to the problem of universals contrasts with Plato's. Whereas Platonic Forms exist in a separate realm, and can exist uninstantiated in visible things, Aristotelean essences "indwell" in particulars.

Potentiality and Actuality are principles of a dichotomy which Aristotle used throughout his philosophical works to analyze motion, causality and other issues.

The Aristotelean theory of change and causality stretches to four causes: the material, formal, efficient and final. The efficient cause corresponds to what is now know as a cause ''simpliciter''. Final causes are explicitly teleological, a concept now regarded as controversial in science. The Matter/Form dichotomy was to become highly influential in later philosophy as the substance/essence distinction.

Scholasticism and the Middle Ages

Between about 1100 and 1500, philosophy as a discipline took place as part of the Catholic church's teaching system, known as scholasticism. Scholastic philosophy took place within an established framework blending Christian theology with Aristotelean teachings. Although fundamental orthodoxies could not be challenged, there were nonetheless deep metaphysical disagreements, particularly over the problem of universals, which engaged Duns Scotus and Pierre Abelard. William of Ockham is remembered for his principle of ontological parsimony.

Continental rationalism

In the early modern period (17th and 18th centuries), the system-building ''scope'' of philosophy is often linked to the rationalist ''method'' of philosophy, that is the technique of deducing the nature of the world by pure reason. The scholastic concepts of substance and accident were employed.

Leibniz proposed in his Monadology a plurality of non-interacting substances.

Descartes is famous for his Dualism of material and mental substances.

Spinoza believed reality was a single substance of God-or-nature.

British empiricism

British empiricism marked something of a reaction to rationalist and system-building philosophy, or ''speculative'' metaphysics as it was pejoratively termed. The sceptic David Hume famously declared that most metaphysics should be consigned to the flames (see below). Hume was notorious among his contemporaries as one of the first philosophers to openly doubt religion, but is better known now for his critique of causality. John Stuart Mill, Thomas Reid and John Locke were less secptical, embracing a more cautious style of metaphysics based on realism, common sense and science. Other philosophers, notably George Berkely were led from empiricism to idealistic metaphysics.

Kant

Immanuel Kant attempted a grand synthesis and revision of the trends already mentioned: scholastic philosophy, systematic metaphysics, and sceptical empiricism, not to forget the burgeoning science of his day. Like the systems builders, he had an overarching framework in which all questions were to be addressed. Like Hume, who famously woke him from his 'dogmatic slumbers', he was suspicious of metaphysical speculation, and also places much emphasis on the limitations of the human mind.

Kant saw rationalist philosophers as aiming for a kind of metaphysical knowledge he defined as the ''synthetic apriori'' — that is knowledge that does not come from the senses (it is a apriori) but is nonetheless about reality (synthetic). Inasmuch as it is about reality, it is unlike abstract mathematical propositions (which he terms analytical apriori), and being apriori it is distinct from empirical, scientific knowledge (which he terms synthetic aposteriori). The only synthetic apriori knowledge we can have is of how our minds organise the data of the senses; that organising framework is space and time, which for Kant have no mind-independent existence, but nonetheless operate uniformly in all humans. Apriori knowledge of space and time is all that remains of metaphysics as traditionally conceived. There ''is'' a reality beyond sensory data or phenomena, which he calls the realm of noumena; however, we cannot know it as it is in itself, but only as it appears to us. He allows himself to speculate that the origins of God, morality, and free will ''might'' exist in the noumenal realm, but these possibilities have to be set against its basic unknowability for humans. Although he saw himself as having disposed of metaphysics, in a sense, he has generally been regarded in retrospect, as having a metaphysics of his own.

19th Century philosophy was overwhelmingly influenced by Kant and his successors. Schopenhauer, Schelling, Fichte and Hegel all purveyed their own panoramic versions of German Idealism, Kant's own caution about metaphysical speculation, and refutation of idealism, having fallen by the wayside. The idealistic impulse continued into the early 20th century with British idealists such as F. H. Bradley and J. M. E. McTaggart.

Followers of Karl Marx took Hegel's dialectic view of history and re-fashioned it as materialism.

Early analytical philosophy and positivism

During the period when idealism was dominant in philosophy, science had been making great advances. The arrival of a new generation of scientifically minded philosophers led to a sharp decline in the popularity of idealism during the 1920s.

Analytical philosophy was spearheaded by Bertrand Russell and G. E. Moore. Russell and William James tried to compromise between idealism and materialism with the theory of neutral monism.

The early to mid 20th century philosophy also saw a trend to reject metaphysical questions as meaningless. The driving force behind this tendency was the unabashedly materialist philosophy of Logical Positivism as espoused by the Vienna Circle. See "The Value and Future of Metaphysics" below.

At around the same time, the American pragmatists were steering a middle course between materialism and idealism. System-building metaphysics, with a fresh inspiration from science, was revived by A. N. Whitehead and Charles Hartshorne.

Continental philosophy

The forces that shaped analytical philosophy — the break with idealism, and the influence of science — were much less significant outside the English speaking world, although there was a shared turn toward language. Continental philosophy continued in a trajectory from post Kantianism.

The phenomenology of Husserl and others was intended as a collaborative project for the investigation of the features and structure of consciousness common to all humans, in line with Kant's basing his synthetic apriori on the uniform operation of consciousness. It was officially neutral with regards to ontology, but was nonetheless to spawn a number of metaphysical systems. Brentano's concept of intentionality would become widely influential, including on analytical philosophy.

Heidegger, author of Being and Time, saw himself as re-focusing on Being-qua-being, introducing the novel concept of ''Dasein'' in the process. Classing himself an existentialist, Sartre wrote an extensive study of "Being and Nothingness''.

The speculative realism movement marks a return to full blooded realism.

Later analytical philosophy

Whilst early analytic philosophy tended to reject metaphysical theorizing, under the influence of logical positivism, it was revived in the second half of the twentieth century. Philosophers such as David Kellogg Lewis and David Armstrong developed elaborate theories on a range of topics such as universals, causation, possibility and necessity and abstract objects. However, the focus of analytical philosophy is generally away from the construction of all-encompassing systems and towards close analysis of individual ideas.

Among the developments that led to the revival of metaphysical theorizing were Quine's attack on the analytic-synthetic distinction, which was generally taken to undermine Carnap's distinction between existence questions internal to a framework and those external to it.

The philosophy of fiction, the problem of empty names, and the debate over existence's status as a property have all risen out of relative obscurity to become central concerns, while perennial issues such as free will, possible worlds, and the philosophy of time have had new life breathed into them.

The value and future of metaphysics

A number of individuals have suggested that metaphysics as a whole should be rejected.

David Hume argued with his empiricist principle that all knowledge involves either relations of ideas or matters of fact:

However, Hume's assertion may be self-defeating if it itself is not self-evident or empirically verifiable.

Immanuel Kant prescribed a limited role to the subject and argued against knowledge progressing beyond the world of our representations, except to knowledge that the ''noumena'' exist:

Proceeding from Kant's statement about antinomy, A.J. Ayer in ''Language, Truth and Logic'' using the verifiability theory of meaning concluded that metaphysical propositions were neither true nor false but strictly meaningless, as were religious views. However, Karl Popper argued that metaphysical statements are not ''meaningless'' statements, but rather not ''fallible'', ''testable'' or ''provable'' statements i.e. neither empirical observations nor logical arguments could falsify metaphysical statements to show them to be true or false. Hence, a metaphysical statement usually implies an ''idea'' about the world or about the universe, which may be reasonable but is ultimately not empirically testable.

Rudolf Carnap, in his book ''Philosophy and Logical Syntax'', used the concept of verifiability to reject metaphysics.

John Locke, a founder of empiricism, expressed that most of the doctrine of innate ideas in the metaphysics, such as Cartesian dualism and the Platonic realm were ridiculous and nonsensical.

See also

Concerning existence of material things, and real distinction between mind and body (Descartes)

Essence

Logic

Metaethics

Nihilism

Personal identity (philosophy)

Philosophical logic

Philosophical theology

Philosophy of Mathematics

Philosophy of physics

Pluralism (philosophy of mind)

Philosophical realism

Substance theory

Alchemy

Time travel

Further reading

The London Philosophy Study Guide offers many suggestions on what to read, depending on the student's familiarity with the subject: Logic & Metaphysics

Notes and references

Bibliography

Butchvarov, Panayot (1979). ''Being Qua Being: A Theory of Identity, Existence and Predication''. Bloomington and London: Indiana University Press.

Harris, E. E. (1965). ''The Foundations of Metaphysics in Science''. London: George Allen and Unwin.

Harris, E. E. (2000). ''The Restitution of Metaphysics''. New York: Humanity Books.

Kant, I (1781). ''Critique of Pure Reason''.

Gale, Richard M. (2002). ''The Blackwell Guide to Metaphysics''. Oxford: Blackwell.

Gay, Peter. (1966). ''The Enlightenment: An Interpretation'' (2 vols.). New York: W. W. Norton & Company.

Lowe, E. J. (2002). ''A Survey of Metaphysics''. Oxford: Oxford University Press.

Loux, M. J. (2006). ''Metaphysics: A Contemporary Introduction'' (3rd ed.). London: Routledge.

Kim, J. and Ernest Sosa Ed. (1999). ''Metaphysics: An Anthology''. Blackwell Philosophy Anthologies.

Kim, J. and Ernest Sosa, Ed. (2000). ''A Companion to Metaphysics''. Malden Massachusetts, Blackwell, Publishers.

Le Poidevin R. & al. Ed. (2009). ''The Routledge Companion to Metaphysics''. New York, Routledge.

Werner Heisenberg (1958), Atomic Physics and Causal Law, from The Physicist’s Conception of Nature

External links

Research articles in Metaphysics - PhilPapers

Aristotle's Metaphysics trans. by W. D. Ross

Hume's Enquiry Concerning Human Understanding: Mirrored at eBooks@Adelaide

Aristotle's Metaphysics trans. by Hugh Tredennick (HTML at Perseus)

E-text (The Norman Kemp Smith translation of Kant's Critique of Pure Reason)

Category:Physics Category:Branches of philosophy

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Coordinates	67°52′34″N178°44′20″N
Name	Stephen Hawking
Birth name	Stephen William Hawking
Birth date	January 08, 1942
Birth place	Oxford, England, United Kingdom
Residence	United Kingdom
Nationality	British
Fields	Applied mathematicsTheoretical physicsCosmology
Workplaces	Cambridge UniversityCalifornia Institute of TechnologyPerimeter Institute for Theoretical Physics
Alma mater	Oxford UniversityCambridge University
Doctoral advisor	Dennis Sciama
Academic advisors	Robert Berman
Doctoral students	Bruce AllenRaphael BoussoFay DowkerMalcolm PerryBernard CarrGary GibbonsHarvey ReallDon PageTim PrestidgeRaymond LaflammeJulian Luttrell
Known for	Black holesTheoretical cosmologyQuantum gravityHawking radiation
Influences	Dikran TahtaAlbert Einstein
Awards
Spouse	Jane Hawking(m. 1965–1991, divorced)Elaine Mason(m. 1995–2006, divorced)
Signature	Hawkingsig.svg }}

Stephen William Hawking, CH, CBE, FRS, FRSA (born 8 January 1942) is a British theoretical physicist and cosmologist, whose scientific books and public appearances have made him an academic celebrity. He is an Honorary Fellow of the Royal Society of Arts, a lifetime member of the Pontifical Academy of Sciences, and in 2009 was awarded the Presidential Medal of Freedom, the highest civilian award in the United States.

Hawking was the Lucasian Professor of Mathematics at the University of Cambridge for 30 years, taking up the post in 1979 and retiring on 1 October 2009. He is now Director of Research at the Centre for Theoretical Cosmology in the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge. He is also a Fellow of Gonville and Caius College, Cambridge and a Distinguished Research Chair at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario. He is known for his contributions to the fields of cosmology and quantum gravity, especially in the context of black holes. He has also achieved success with works of popular science in which he discusses his own theories and cosmology in general; these include the runaway best seller ''A Brief History of Time'', which stayed on the British ''Sunday Times'' best-sellers list for a record-breaking 237 weeks.

Hawking's key scientific works to date have included providing, with Roger Penrose, theorems regarding gravitational singularities in the framework of general relativity, and the theoretical prediction that black holes should emit radiation, which is today known as Hawking radiation (or sometimes as Bekenstein–Hawking radiation).

Hawking has a motor neurone disease that is related to amyotrophic lateral sclerosis, a condition that has progressed over the years and has left him almost completely paralysed.

Early life

Stephen Hawking was born on 8 January 1942 to Dr. Frank Hawking, a research biologist, and Isobel Hawking. He had two younger sisters, Philippa and Mary, and an adopted brother, Edward. Though Hawking's parents were living in North London, they moved to Oxford while his mother was pregnant with Stephen, desiring a safer location for the birth of their first child. (London was under attack at the time by the Luftwaffe.) According to Hawking, a German V-2 missile struck only a few streets away.

After Hawking was born, the family moved back to London, where his father headed the division of parasitology at the National Institute for Medical Research. In 1950, Hawking and his family moved to St Albans, Hertfordshire, where he attended St Albans High School for Girls from 1950 to 1953. (At that time, boys could attend the Girls' school until the age of ten.) From the age of eleven, he attended St Albans School, where he was a good, but not exceptional, student. When asked later to name a teacher who had inspired him, Hawking named his mathematics teacher Dikran Tahta. He maintains his connection with the school, giving his name to one of the four houses and to an extracurricular science lecture series. He has visited it to deliver one of the lectures and has also granted a lengthy interview to pupils working on the school magazine, ''The Albanian''.

Hawking was always interested in science. Inspired by his mathematics teacher, he originally wanted to study the subject at university. However, Hawking's father wanted him to apply to University College, Oxford, where his father had attended. As University College did not have a mathematics fellow at that time, it would not accept applications from students who wished to read that discipline. Hawking therefore applied to read natural sciences, in which he gained a scholarship. Once at University College, Hawking specialised in physics. His interests during this time were in thermodynamics, relativity, and quantum mechanics. His physics tutor, Robert Berman, later said in ''The New York Times Magazine'':

Hawking was passing, but his unimpressive study habits resulted in a final examination score on the borderline between first and second class honours, making an "oral examination" necessary. Berman said of the oral examination:

After receiving his B.A. degree at Oxford in 1962, he stayed to study astronomy. He decided to leave when he found that studying sunspots, which was all the observatory was equipped for, did not appeal to him and that he was more interested in theory than in observation. He left Oxford for Trinity Hall, Cambridge, where he engaged in the study of theoretical astronomy and cosmology.

Career

Almost as soon as he arrived at Cambridge, he started developing symptoms of amyotrophic lateral sclerosis (ALS, known colloquially in the United States as Lou Gehrig's disease), a type of motor neurone disease which would cost him almost all neuromuscular control. During his first two years at Cambridge, he did not distinguish himself, but, after the disease had stabilised and with the help of his doctoral tutor, Dennis William Sciama, he returned to working on his PhD.

Hawking was elected as one of the youngest Fellows of the Royal Society in 1974, was created a Commander of the Order of the British Empire in 1982, and became a Companion of Honour in 1989. Hawking is a member of the Board of Sponsors of the ''Bulletin of the Atomic Scientists''.

In 1974, he accepted the Sherman Fairchild Distinguished Scholar visiting professorship at the California Institute of Technology (Caltech) to work with his friend, Kip Thorne, who was a faculty member there. He continues to have ties with Caltech, spending a month each year there since 1992.

Hawking's achievements were made despite the increasing paralysis caused by the ALS. By 1974, he was unable to feed himself or get out of bed. His speech became slurred so that he could be understood only by people who knew him well. In 1985, he caught pneumonia and had to have a tracheotomy, which made him unable to speak at all. A Cambridge scientist built a device that enables Hawking to write onto a computer with small movements of his body, and then have a voice synthesiser speak what he has typed.

Research fields

Hawking's principal fields of research are theoretical cosmology and quantum gravity.

In the late 1960s, he and his Cambridge friend and colleague, Roger Penrose, applied a new, complex mathematical model they had created from Albert Einstein's theory of general relativity. This led, in 1970, to Hawking proving the first of many singularity theorems; such theorems provide a set of sufficient conditions for the existence of a gravitational singularity in space-time. This work showed that, far from being mathematical curiosities which appear only in special cases, singularities are a fairly generic feature of general relativity.

He supplied a mathematical proof, along with Brandon Carter, Werner Israel and D. Robinson, of John Wheeler's no-hair theorem – namely, that any black hole is fully described by the three properties of mass, angular momentum, and electric charge.

Hawking also suggested upon analysis of gamma ray emissions that after the Big Bang, primordial mini black holes were formed. With Bardeen and Carter, he proposed the four laws of black hole mechanics, drawing an analogy with thermodynamics. In 1974, he calculated that black holes should thermally create and emit subatomic particles, known today as Bekenstein-Hawking radiation, until they exhaust their energy and evaporate.

In collaboration with Jim Hartle, Hawking developed a model in which the universe had no boundary in space-time, replacing the initial singularity of the classical Big Bang models with a region akin to the North Pole: one cannot travel north of the North Pole, as there is no boundary. While originally the no-boundary proposal predicted a closed universe, discussions with Neil Turok led to the realisation that the no-boundary proposal is also consistent with a universe which is not closed.

Along with Thomas Hertog at CERN, in 2006 Hawking proposed a theory of "top-down cosmology," which says that the universe had no unique initial state, and therefore it is inappropriate for physicists to attempt to formulate a theory that predicts the universe's current configuration from one particular initial state. Top-down cosmology posits that in some sense, the present "selects" the past from a superposition of many possible histories. In doing so, the theory suggests a possible resolution of the fine-tuning question: It is inevitable that we find our universe's present physical constants, as the current universe "selects" only those past histories that led to the present conditions. In this way, top-down cosmology provides an anthropic explanation for why we find ourselves in a universe that allows matter and life, without invoking an ensemble of multiple universes.

Hawking's many other scientific investigations have included the study of quantum cosmology, cosmic inflation, helium production in anisotropic Big Bang universes, large N cosmology, the density matrix of the universe, topology and structure of the universe, baby universes, Yang-Mills instantons and the S matrix, anti de Sitter space, quantum entanglement and entropy, the nature of space and time, including the arrow of time, spacetime foam, string theory, supergravity, Euclidean quantum gravity, the gravitational Hamiltonian, Brans-Dicke and Hoyle-Narlikar theories of gravitation, gravitational radiation, and wormholes.

At a George Washington University lecture in honour of NASA's fiftieth anniversary, Hawking theorised on the existence of extraterrestrial life, believing that "primitive life is very common and intelligent life is fairly rare."

Losing an old bet

Hawking was in the news in July 2004 for presenting a new theory about black holes which goes against his own long-held belief about their behaviour, thus losing a bet he made with Kip Thorne and John Preskill of Caltech. Classically, it can be shown that information crossing the event horizon of a black hole is lost to our universe, and that thus all black holes are identical beyond their mass, electrical charge and angular velocity (the "no hair theorem"). The problem with this theorem is that it implies the black hole will emit the same radiation regardless of what goes into it, and as a consequence that if a pure quantum state is thrown into a black hole, an "ordinary" mixed state will be returned. This runs counter to the rules of quantum mechanics and is known as the black hole information paradox.

Human spaceflight

At the fiftieth anniversary of NASA in 2008, Hawking gave a keynote speech on the final frontier exhorting and inspiring the space technology community on why we (the human race) explore space.

At the celebration of his sixty-fifth birthday on 8 January 2007, Hawking announced his plan to take a zero-gravity flight in 2007 to prepare for a sub-orbital spaceflight in 2009 on Virgin Galactic's space service. Billionaire Richard Branson pledged to pay all expenses for the latter, costing an estimated £100,000. Stephen Hawking's zero-gravity flight in a "''Vomit Comet''" of Zero Gravity Corporation, during which he experienced weightlessness eight times, took place on 26 April 2007. He became the first quadriplegic to float in zero-gravity. This was the first time in forty years that he moved freely, without his wheelchair. The fee is normally US$3,750 for 10–15 plunges, but Hawking was not required to pay the fee. A bit of a futurist, Hawking was quoted before the flight saying: }} In an interview with ''The Daily Telegraph'', he suggested that space was the Earth's long term hope. He continued this theme at a 2008 Charlie Rose interview.

Existence and nature of extraterrestrial life

Hawking has indicated that he is almost certain that alien life exists in other parts of the universe and uses a mathematical basis for his assumptions. "To my mathematical brain, the numbers alone make thinking about aliens perfectly rational. The real challenge is to work out what aliens might actually be like." He believes alien life not only certainly exists on planets but perhaps even in other places, like within stars or even floating in outer space. He also warns that a few of these species might be intelligent and threaten Earth. Contact with such species might be devastating for humanity. "If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans," he said. He advocated that, rather than try to establish contact, humans should try to avoid contact with alien life forms.

Illness

Stephen Hawking is severely disabled by a motor neurone disease known as Amyotrophic lateral sclerosis (ALS), sometimes known as Lou Gehrig's disease. Hawking's illness is markedly different from typical ALS because if confirmed, Hawking's case would make for the most protracted case ever documented. A survival for more than ten years after diagnosis is uncommon for ALS; the longest documented durations, other than Hawking's, are 32 and 39 years and these cases were termed benign because of the lack of the typical progressive course.

When he was young, he enjoyed riding horses. At Oxford, he coxed a rowing team, which, he stated, helped relieve his immense boredom at the university. Symptoms of the disorder first appeared while he was enrolled at University of Cambridge; he lost his balance and fell down a flight of stairs, hitting his head. Worried that he would lose his genius, he took the Mensa test to verify that his intellectual abilities were intact. The diagnosis of motor neurone disease came when Hawking was 21, shortly before his first marriage, and doctors said he would not survive more than two or three years. Hawking gradually lost the use of his arms, legs, and voice, and as of 2009 has been almost completely paralysed.

During a visit to the research centre CERN in Geneva in 1985, Hawking contracted pneumonia, which in his condition was life-threatening as it further restricted his already limited respiratory capacity. He had an emergency tracheotomy, and as a result lost what remained of his ability to speak. He has since used an electronic voice synthesiser to communicate.

The DECtalk DTC01 voice synthesiser he uses, which has an American English accent, is no longer being produced. Asked why he has still kept it after so many years, Hawking mentioned that he has not heard a voice he likes better and that he identifies with it. Hawking is said to be looking for a replacement since, aside from being obsolete, the synthesiser is both large and fragile by current standards. As of mid 2009, he was said to be using NeoSpeech's VoiceText speech synthesiser.

In Hawking's many media appearances, he appears to speak fluently through his synthesiser, but in reality, it is a tedious drawn-out process. Hawking's setup uses a predictive text entry system, which requires only the first few characters in order to auto-complete the word, but as he is only able to use his cheek for data entry, constructing complete sentences takes time. His speeches are prepared in advance, but having a live conversation with him provides insight as to the complexity and work involved. During a TED Conference talk, it took him seven minutes to answer a question.

He describes himself as lucky, despite his disease. Its slow progression has allowed him time to make influential discoveries and has not hindered him from having, in his own words, "a very attractive family." When his wife, Jane, was asked why she decided to marry a man with a three-year life expectancy, she responded, "Those were the days of atomic gloom and doom, so we all had a rather short life expectancy." On 20 April 2009, Cambridge University released a statement saying that Hawking was "very ill" with a chest infection, and was admitted to Addenbrooke's Hospital. The following day, it was reported that his new condition was "comfortable" and he would make a full recovery from the infection.

As popular science advocate

Hawking has played himself on numerous television shows and has been portrayed in many more. He has played himself on a ''Red Dwarf'' anniversary special, played a hologram of himself on the episode "Descent" of ''Star Trek: The Next Generation'', appeared in a skit on ''Late Night with Conan O'Brien'', and appeared on the Discovery Channel special ''Alien Planet''. He has also played himself in several episodes of ''The Simpsons'' and ''Futurama'', and has had an action figure made of his ''Simpsons'' likeness. In 2008, Hawking was the subject of and featured in the documentary series ''Stephen Hawking, Master of the Universe'' for Channel 4. In September 2008, Hawking presided over the unveiling of the 'Chronophage' (time-eating) Corpus Clock at Corpus Christi College Cambridge. His actual synthesiser voice was used on parts of the Pink Floyd song "Keep Talking" from the 1994 album ''The Division Bell'', as well as on Turbonegro's "Intro: The Party Zone" on their 2005 album ''Party Animals'', Wolfsheim's "Kein Zurück (Oliver Pinelli Mix)".

Recognition

Acclaim

On 19 December 2007, a statue of Hawking by renowned late artist Ian Walters was unveiled at the Centre for Theoretical Cosmology, University of Cambridge. In May 2008, the statue of Hawking was unveiled at the African Institute for Mathematical Sciences in Cape Town. The Stephen W. Hawking Science Museum in San Salvador, El Salvador is named in honour of Stephen Hawking, citing his scientific distinction and perseverance in dealing with adversity. Stephen Hawking Building in Cambridge opened on 17 April 2007. The building belongs to Gonville and Caius College and is used as an undergraduate accommodation and conference facility.

Distinctions

Hawking's belief that the lay person should have access to his work led him to write a series of popular science books in addition to his academic work. The first of these, ''A Brief History of Time'', was published on 1 April 1988 by Hawking, his family and friends, and some leading physicists. It surprisingly became a best-seller and was followed by ''The Universe in a Nutshell'' (2001). Both books have remained highly popular all over the world. A collection of essays titled ''Black Holes and Baby Universes'' (1993) was also popular. His book, ''A Briefer History of Time'' (2005), co-written by Leonard Mlodinow, aims to update his earlier works and make them accessible to an even wider audience. In 2007 Hawking and his daughter, Lucy Hawking, published ''George's Secret Key to the Universe'', a children's book focusing on science that has been described as "like ''Harry Potter'', but without the magic." The book includes information on Hawking radiation.

Hawking supports the children's charity SOS Children's Villages UK.

Awards and honours

1975 Eddington Medal

1976 Hughes Medal of the Royal Society

1979 Albert Einstein Medal

1981 Franklin Medal

1982 Order of the British Empire (Commander)

1985 Gold Medal of the Royal Astronomical Society

1986 Member of the Pontifical Academy of Sciences

1988 Wolf Prize in Physics

1989 Prince of Asturias Awards in Concord

1989 Companion of Honour

1999 Julius Edgar Lilienfeld Prize of the American Physical Society

2003 Michelson Morley Award of Case Western Reserve University

2006 Copley Medal of the Royal Society 2008 Fonseca Prize of the University of Santiago de Compostela 2009 Presidential Medal of Freedom, the highest civilian honour in the United States

Personal life

Hawking revealed that he did not see much point in obtaining a doctorate if he were to die soon. Hawking later said that the real turning point was his 1965 marriage to Jane Wilde, a language student. After gaining his PhD at Trinity Hall, he became first a Research Fellow, and later on a Professorial Fellow at Gonville and Caius College. Jane Hawking (née Wilde), Hawking's first wife, cared for him until 1991 when the couple separated, reportedly because of the pressures of fame and his increasing disability. They had three children: Robert, Lucy, and Timothy. Hawking then married his nurse, Elaine Mason (who was previously married to David Mason, the designer of the first version of Hawking's talking computer), in 1995. In October 2006, Hawking filed for divorce from his second wife amid claims by former nurses that she had abused him.

In 1999, Jane Hawking published a memoir, ''Music to Move the Stars'', detailing the marriage and his breakdown; in 2010 she published a revised version, ''Travelling to Infinity, My Life with Stephen''. Hawking's daughter, Lucy, is a novelist. Their oldest son, Robert, emigrated to the United States, married, and has a son. After a period of estrangement, Hawking and his first family were reconciled in 2007.

His view on how to live life is to "seek the greatest value of our action".

Hawking was asked about his IQ in a 2004 newspaper interview, and replied, "I have no idea. People who boast about their I.Q. are losers." Yet when asked "Are you saying you are not a genius?", Hawking replied "I hope I'm near the upper end of the range."

Hawking strongly opposed the US-led Iraq War, calling it "a war crime" and "based on lies". In 2004, he personally attended a demonstration against the war in Trafalgar Square, and participated in a public reading of the names of Iraqi war victims.

Religious views

In his early work, Hawking spoke of "God" in a metaphorical sense, such as in ''A Brief History of Time'': "If we discover a complete theory, it would be the ultimate triumph of human reason—for then we should know the mind of God." In the same book he suggested the existence of God was unnecessary to explain the origin of the universe. His 2010 book ''The Grand Design'' and interviews with the ''Telegraph'' and the Channel 4 documentary ''Genius of Britain'', clarify that he does "not believe in a personal God". Hawking writes, "The question is: is the way the universe began chosen by God for reasons we can't understand, or was it determined by a law of science? I believe the second." He adds, "Because there is a law such as gravity, the Universe can and will create itself from nothing."

His ex-wife, Jane, said during their divorce proceedings that he was an atheist. Hawking has stated that he is "not religious in the normal sense" and he believes that "the universe is governed by the laws of science. The laws may have been decreed by God, but God does not intervene to break the laws." In an interview published in ''The Guardian'' newspaper, Hawking regarded the concept of Heaven as a myth, stating that there is "no heaven or afterlife" and that such a notion was a "fairy story for people afraid of the dark."

Hawking contrasted religion and science in 2010, saying: "There is a fundamental difference between religion, which is based on authority, [and] science, which is based on observation and reason. Science will win because it works."

Selected publications

Technical

''Singularities in Collapsing Stars and Expanding Universes'' with Dennis William Sciama, 1969 Comments on Astrophysics and Space Physics Vol 1 No.1

''The Large Scale Structure of Space-Time'' with George Ellis, 1973, ISBN 0-521-09906-4

''The Nature of Space and Time'' with Roger Penrose, foreword by Michael Atiyah, New Jersey: Princeton University Press, 1996, ISBN 0-691-05084-8

''The Large, the Small, and the Human Mind'', (with Abner Shimony, Nancy Cartwright, and Roger Penrose), Cambridge University Press, 1997, ISBN 0-521-56330-5 (hardback), ISBN 0-521-65538-2 (paperback), Canto edition: ISBN 0-521-78572-3

''Information Loss in Black Holes'', Cambridge University Press, 2005

''God Created the Integers: The Mathematical Breakthroughs That Changed History'', Running Press, 2005 ISBN 0762419229

Popular

''A Brief History of Time'', (Bantam Press 1988) ISBN 055305340X

''Black Holes and Baby Universes and Other Essays'', (Bantam Books 1993) ISBN 0553374117

''The Universe in a Nutshell'', (Bantam Press 2001) ISBN 055380202X

''On The Shoulders of Giants. The Great Works of Physics and Astronomy'', (Running Press 2002) ISBN 076241698X

''A Briefer History of Time'', coauthored with Leonard Mlodinow, (Bantam Books 2005) ISBN 0553804367

''The Grand Design'', coauthored with Leonard Mlodinow, (Bantam Press 2010) ISBN 0553805371

Children's fiction

These are co-written with his daughter Lucy.

''George's Secret Key to the Universe'', (Random House, 2007) ISBN 9780385612708

''George's Cosmic Treasure Hunt'', (Simon & Schuster, 2009) ISBN 9781416986713

Films and series

''A Brief History of Time'' (1991)

''Stephen Hawking's Universe'' (1997)

''Horizon: The Hawking Paradox'' (2005)

''Masters of Science Fiction'' (2007)

''Stephen Hawking: Master of the Universe'' (2008) ''Into The Universe with Stephen Hawking'' (2010) A list of Hawking's publications through the year 2002 is available on his website.

See also

Basic concepts of quantum mechanics

Many-worlds interpretation, or flexiverse

Susskind–Hawking battle – see Black hole information paradox

References

Further reading

A layman's guide to Stephen Hawking

Ferguson, Kitty (1991). ''Stephen Hawking: Quest For A Theory of Everything''. Franklin Watts. ISBN 0-553-29895-X

Highly influential in the field. A much cited centennial survey.

Pickover, Clifford, ''Archimedes to Hawking: Laws of Science and the Great Minds Behind Them'', Oxford University Press, 2008, ISBN 978-0195336115

External links

Stephen Hawking's web site

Stephen Hawking's page on Academia.edu

The Life of Stephen Hawking – slideshow by ''The First Post''

Video: Stephen Hawking – discussion of two views of the universe

Videos: Stephen Hawking's concept of God, The role of God within the no boundary cosmology and Imaginary time

;Dated

Stephen Hawking says universe not created by God

Public Lectures, including debate with Roger Penrose 1996–2006

''Hawking celebrates own brief history'', 7 January 2002, BBC

"Leaping the Abyss", interview in ''Reason'' by Gregory Benford 2002-04-01

2002-03-24

''Black holes turned "inside out"'', 22 July 2004, BBC

''Return of the time lord'', Interview about "A Brief History of Time", 27 September 2005, The Guardian.

Stephen Hawking touches on God and science – Physicist says Pope John Paul told scientists not to study universe's origins msnbc June 2006

Press Release from the Catholic League on misquote of Pope by Hawking 2006-06-16

BBC interview 2008-12-05

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Coordinates	67°52′34″N178°44′20″N
Region	Western Philosophy
Era	18th-century philosophy
Color	#B0C4DE
Name	Immanuel Kant
Birth date	22 April 1724
Birth place	Königsberg, Prussia (Now Kaliningrad, Russia)
Death date	February 12, 1804
Death place	Königsberg, Prussia
School tradition	Kantianism, enlightenment philosophy
Main interests	Epistemology, Metaphysics, Ethics, Logic
Influences	Wolff, Baumgarten, Tetens, Hutcheson, Empiricus, Montaigne, Hume, Descartes, Malebranche, Spinoza, Leibniz, Locke, Berkeley, Rousseau, Newton, Emanuel Swedenborg, Shaftesbury
Influenced	Virtually all later Western Philosophy including: Fichte, Schelling, Hegel, Schopenhauer, Nietzsche, Peirce, Husserl, Heidegger, Sartre, Cassirer, Habermas, Rawls, Chomsky, Nozick, Popper, Kierkegaard, Jung, Searle, Foucault, Arendt, Gentile, Jaspers, Bergson, Ørsted, Ayer, Emerson, Weininger, Strawson, Strauss, Putnam, McDowell, Durkheim
Notable ideas	Categorical imperative, Transcendental Idealism, Synthetic a priori, Noumenon, Sapere aude, Nebular hypothesis
Signature	Autograph-ImmanuelKant.png }}

Immanuel Kant (; 22 April 1724 – 12 February 1804) was a German philosopher from Königsberg (today Kaliningrad of Russia), researching, lecturing and writing on philosophy and anthropology at the end of the 18th Century Enlightenment.

At the time, there were major successes and advances in the sciences (for example, Isaac Newton, Carl Friedrich Gauss, and Robert Boyle) using reason and logic. But this stood in sharp contrast to the scepticism and lack of agreement or progress in empiricist philosophy.

Kant’s magnum opus, the ''Critique of Pure Reason'', aimed to unite reason with experience to move beyond what he took to be failures of traditional philosophy and metaphysics. He hoped to end an age of speculation where objects outside experience were used to support what he saw as futile theories, while opposing the scepticism and idealism of thinkers such as Descartes, Berkeley and Hume.

He said that ‘it always remains a scandal of philosophy and universal human reason that the existence of things outside us ... should have to be assumed merely on faith, and that if it occurs to anyone to doubt it, we should be unable to answer him with a satisfactory proof’. Kant proposed a ‘Copernican Revolution’, saying that 'Up to now it has been assumed that all our cognition must conform to the objects; but ...let us once try whether we do not get farther with the problems of metaphysics by assuming that the objects must conform to our cognition'.

Kant published other important works on religion, law, aesthetics, astronomy and history. These included the ''Critique of Practical Reason'' (''Kritik der praktischen Vernunft'', 1788), which deals with ethics, and the ''Critique of Judgment'' (''Kritik der Urteilskraft'', 1790), which looks at aesthetics and teleology. He aimed to resolve disputes between empirical and rationalist approaches. The former asserted that all knowledge comes through experience; the latter maintained that reason and innate ideas were prior. Kant argued that experience is purely subjective without first being processed by pure reason. He also said that using reason without applying it to experience will only lead to theoretical illusions. The free and proper exercise of reason by the individual was both a theme of the Enlightenment, and of Kant's approaches to the various problems of philosophy.

His ideas influenced many thinkers in Germany during his lifetime. He settled, and moved philosophy beyond, the debate between the rationalists and empiricists. The philosophers Fichte, Schelling, Hegel and Schopenhauer amended and developed the Kantian system, thus bringing about various forms of German idealism. He is seen as a major figure in the history and development of philosophy. German and European thinking progressed after his time, and his influence still inspires philosophical work today.

Biography

Immanuel Kant was born in 1724 in Königsberg, the capital of Prussia at that time, today the city of Kaliningrad in the Russian exclave of Kaliningrad Oblast. He was the fourth of eleven children (four of them reached adulthood). Baptized 'Emanuel', he changed his name to 'Immanuel' after learning Hebrew. In his entire life, he never traveled more than ten miles from Königsberg. His father, Johann Georg Kant (1682–1746), was a German harnessmaker from Memel, at the time Prussia's most northeastern city (now Klaipėda, Lithuania). His mother, Regina Dorothea Reuter (1697–1737), was born in Nuremberg. Kant's grandfather had emigrated from Scotland to East Prussia, and his father still spelled their family name "Cant." In his youth, Kant was a solid, albeit unspectacular, student. He was brought up in a Pietist household that stressed intense religious devotion, personal humility, and a literal interpretation of the Bible. Consequently, Kant received a stern education strict, punitive, and disciplinary that preferred Latin and religious instruction over mathematics and science. The common myths concerning Kant's personal mannerisms are enumerated, explained, and refuted in Goldthwait's introduction to his translation of ''Observations on the Feeling of the Beautiful and Sublime''. It is often held that Kant lived a very strict and predictable life, leading to the oft-repeated story that neighbors would set their clocks by his daily walks. He never married, but did not seem to lack a rewarding social life - he was a popular teacher and a modestly successful author even before starting on his major philosophical works.

The young scholar

Kant showed a great aptitude to study at an early age. He was first sent to Collegium Fredericianum and then enrolled at the University of Königsberg (where he would spend his entire career) in 1740, at the age of 16. He studied the philosophy of Leibniz and Wolff under Martin Knutzen, a rationalist who was also familiar with developments in British philosophy and science and who introduced Kant to the new mathematical physics of Newton. Knutzen dissuaded Kant from the theory of pre-established harmony, which he regarded as "the pillow for the lazy mind". He also dissuaded the young scholar from idealism, which was negatively regarded by most philosophers in the 18th century (The theory of transcendental idealism that Kant developed in the "Critique of Pure Reason" is not traditional idealism, i.e. the idea that reality is purely mental. In fact, Kant produced arguments against traditional idealism in the second part of the "Critique of Pure Reason"). His father's stroke and subsequent death in 1746 interrupted his studies. Kant became a private tutor in the smaller towns surrounding Königsberg, but continued his scholarly research. 1749 saw the publication of his first philosophical work, ''Thoughts on the True Estimation of Living Forces''.

Early work

Kant is best known for his transcendental idealist philosophy that time and space are not materially real but merely the ideal a priori condition of our internal intuition. But he worked in other areas as well. He made an important astronomical discovery, namely the discovery of the retardation of the rotation of the Earth, for which he won the Berlin Academy Prize in 1754. Even more importantly, from this Kant concluded that time is not a thing in itself determined from experience, objects, motion, and change, but rather an unavoidable framework of the human mind that preconditions possible experience.

According to Lord Kelvin:

He became a university lecturer in 1755. The subject on which he lectured was "Metaphysics"; the course textbook was written by A.G. Baumgarten.

According to Thomas Huxley:

In the ''General History of Nature and Theory of the Heavens (Allgemeine Naturgeschichte und Theorie des Himmels)'' (1755), Kant laid out the Nebular hypothesis, in which he deduced that the Solar System formed from a large cloud of gas, a nebula. He thus attempted to explain the order of the solar system, seen previously by Newton as being imposed from the beginning by God. Kant also correctly deduced that the Milky Way was a large disk of stars, which he theorized also formed from a (much larger) spinning cloud of gas. He further suggested the possibility that other nebulae might also be similarly large and distant disks of stars. These postulations opened new horizons for astronomy: for the first time extending astronomy beyond the solar system to galactic and extragalactic realms.

From this point on, Kant turned increasingly to philosophical issues, although he continued to write on the sciences throughout his life. In the early 1760s, Kant produced a series of important works in philosophy. ''The False Subtlety of the Four Syllogistic Figures'', a work in logic, was published in 1762. Two more works appeared the following year: ''Attempt to Introduce the Concept of Negative Magnitudes into Philosophy'' and ''The Only Possible Argument in Support of a Demonstration of the Existence of God''. In 1764, Kant wrote ''Observations on the Feeling of the Beautiful and Sublime'' and then was second to Moses Mendelssohn in a Berlin Academy prize competition with his ''Inquiry Concerning the Distinctness of the Principles of Natural Theology and Morality'' (often referred to as "the Prize Essay"). In 1770, at the age of 45, Kant was finally appointed Professor of Logic and Metaphysics at the University of Königsberg. Kant wrote his ''inaugural dissertation'' in defence of this appointment. This work saw the emergence of several central themes of his mature work, including the distinction between the faculties of intellectual thought and sensible receptivity. Not to observe this distinction would mean to commit the error of subreption, and, as he says in the last chapter of the dissertation, only in avoidance of this error will metaphysics flourish.

The issue that vexed Kant was central to what twentieth century scholars termed "the philosophy of mind." The flowering of the natural sciences had led to an understanding of how data reaches the brain. Sunlight may fall upon a distant object, whereupon light is reflected from various parts of the object in a way that maps the surface features (color, texture, etc.) of the object. The light reaches the eye of a human observer, passes through the cornea, is focused by the lens upon the retina where it forms an image similar to that formed by light passing through a pinhole into a camera obscura. The retinal cells next send impulses through the optic nerve and thereafter they form a mapping in the brain of the visual features of the distant object. The interior mapping is not the exterior thing being mapped, and our belief that there is a meaningful relationship between the exterior object and the mapping in the brain depends on a chain of reasoning that is not fully grounded. But the uncertainty aroused by these considerations, the uncertainties raised by optical illusions, misperceptions, delusions, etc., are not the end of the problems.

Kant saw the mind could not function as an empty container that simply receives data from the outside. Something had to be giving order to the incoming data. Images of external objects have to be kept in the same sequence in which they were received. This ordering occurs through the mind's intuition of time. The same considerations apply to the mind's function of constituting space for ordering mappings of visual and tactile signals arriving via the already described chains of physical causation.

It is often held that Kant was a late developer, that he only became an important philosopher in his mid-50s after rejecting his earlier views. While it is true that Kant wrote his greatest works relatively late in life, there is a tendency to underestimate the value of his earlier works. Recent Kant scholarship has devoted more attention to these "pre-critical" writings and has recognized a degree of continuity with his mature work.

The silent decade

At the age of 46, Kant was an established scholar and an increasingly influential philosopher. Much was expected of him. In correspondence with his ex-student and friend, Markus Herz, Kant admitted that in the ''Inaugural Dissertation'', he had failed to account for the relation and connection between our sensible and intellectual faculties, i.e., he needed to explain how we combine sensory with reasoned knowledge, related but very different processes. He also credited David Hume with awakening him from "dogmatic slumber" (circa 1771). Hume stated that experience consists only of sequences of feelings, images or sounds. Ideas such as 'cause', goodness, or objects were not evident in experience, so why do we believe in the reality of these? Kant felt that reason could remove this scepticism, and he set himself to solving these problems. He did not publish any work in philosophy for the next eleven years. Although fond of company and conversation with others, Kant isolated himself. He resisted friends' attempts to bring him out of his isolation. In 1778, in response to one of these offers by a former pupil, Kant wrote

"Any change makes me apprehensive, even if it offers the greatest promise of improving my condition, and I am persuaded by this natural instinct of mine that I must take heed if I wish that the threads which the Fates spin so thin and weak in my case to be spun to any length. My great thanks, to my well-wishers and friends, who think so kindly of me as to undertake my welfare, but at the same time a most humble request to protect me in my current condition from any disturbance."

When Kant emerged from his silence in 1781, the result was the ''Critique of Pure Reason''. Although now uniformly recognized as one of the greatest works in the history of philosophy, this ''Critique'' was largely ignored upon its initial publication. The book was long, over 800 pages in the original German edition, and written in what some considered a convoluted style. It received few reviews, and these granted no significance to the work. Its density made it, as Johann Gottfried Herder put it in a letter to Johann Georg Hamann, a "tough nut to crack," obscured by "...all this heavy gossamer." Its reception stood in stark contrast to the praise Kant had received for earlier works such as his "Prize Essay" and other shorter works that precede the first Critique. These well-received and readable tracts include one on the earthquake in Lisbon which was so popular that it was sold by the page. Prior to the change in course documented in the first Critique, his books sold well, and by the time he published ''Observations On the Feeling of the Beautiful and the Sublime'' in 1764 he had become a popular author of some note. Kant was disappointed with the first Critique's reception. Recognizing the need to clarify the original treatise, Kant wrote the ''Prolegomena to any Future Metaphysics'' in 1783 as a summary of its main views. He also encouraged his friend, Johann Schultz, to publish a brief commentary on the ''Critique of Pure Reason.''

Kant's reputation gradually rose through the 1780s, sparked by a series of important works: the 1784 essay, "Answer to the Question: What is Enlightenment?"; 1785s ''Groundwork of the Metaphysics of Morals'' (his first work on moral philosophy); and, from 1786, ''Metaphysical Foundations of Natural Science.'' But Kant's fame ultimately arrived from an unexpected source. In 1786, Karl Reinhold began to publish a series of public letters on the Kantian philosophy. In these letters, Reinhold framed Kant's philosophy as a response to the central intellectual controversy of the era: the Pantheism Dispute. Friedrich Jacobi had accused the recently deceased G. E. Lessing (a distinguished dramatist and philosophical essayist) of Spinozism. Such a charge, tantamount to atheism, was vigorously denied by Lessing's friend Moses Mendelssohn, and a bitter public dispute arose among partisans. The controversy gradually escalated into a general debate over the values of the Enlightenment and the value of reason itself. Reinhold maintained in his letters that Kant's ''Critique of Pure Reason'' could settle this dispute by defending the authority and bounds of reason. Reinhold's letters were widely read and made Kant the most famous philosopher of his era.

Mature work

Kant published a second edition of the ''Critique of Pure Reason'' (''Kritik der reinen Vernunft'') in 1787, heavily revising the first parts of the book. Most of his subsequent work focused on other areas of philosophy. He continued to develop his moral philosophy, notably in 1788's ''Critique of Practical Reason'' (known as the second ''Critique'') and 1797’s ''Metaphysics of Morals''. The 1790 ''Critique of Judgment'' (the third ''Critique'') applied the Kantian system to aesthetics and teleology.

In 1792, Kant's attempt to publish the Second of the four Pieces of ''Religion within the Bounds of Bare Reason'', in the journal ''Berlinische Monatsschrift'', met with opposition from the king's censorship commission, which had been established that same year in the context of 1789 French Revolution. Kant then arranged to have all four pieces published as a book, routing it through the philosophy department at University of Jena to avoid the need for theological censorship. Kant got the famous reprimand by the King, for this action of insubordination. When he nevertheless published a second edition in 1794, the censor was so irate that he arranged for a royal order that required Kant never to publish or even speak publicly about religion. Kant then published his response to the King's reprimand and explained himself, in the preface of ''The Conflict of the Faculties''.

He also wrote a number of semi-popular essays on history, religion, politics and other topics. These works were well received by Kant's contemporaries and confirmed his preeminent status in eighteenth century philosophy. There were several journals devoted solely to defending and criticizing the Kantian philosophy. But despite his success, philosophical trends were moving in another direction. Many of Kant's most important disciples (including Reinhold, Beck and Fichte) transformed the Kantian position into increasingly radical forms of idealism. The progressive stages of revision of Kant's teachings marked the emergence of German Idealism. Kant opposed these developments and publicly denounced Fichte in an open letter in 1799. It was one of his final acts expounding a stance on philosophical questions. In 1800, a student of Kant, named Gottlob Benjamin Jäsche, published a manual of logic for teachers called ''Logik'', which he had prepared at the request of Kant. Jäsche prepared the ''Logik'' using a copy of a text book in logic by Georg Freidrich Meier entitled ''Auszug aus der Vernunftlehre'', in which Kant had written copious notes and annotations. The ''Logik'' has been considered to be of fundamental importance to Kant's philosophy, and the understanding of it. For, the great nineteenth century logician Charles Sanders Peirce remarked, in an incomplete review of Thomas Kingsmill Abbott's English translation of the introduction to the ''Logik'', that "Kant's whole philosophy turns upon his logic." Also, Robert Schirokauer Hartman and Wolfgang Schwarz, wrote in the translators' introduction to their English translation of the ''Logik'', "Its importance lies not only in its significance for the ''Critique of Pure Reason'', the second part of which is a restatement of fundamental tenets of the ''Logic'', but in its position within the whole of Kant's work." Kant's health, long poor, took a turn for the worse and he died at Königsberg on 12 February 1804 uttering "Genug" [enough] before expiring. His unfinished final work, the fragmentary ''Opus Postumum'', was, as its title suggests, published posthumously.

Philosophy

In Kant's essay "Answering the Question: What is Enlightenment?", Kant defined the Enlightenment as an age shaped by the Latin motto ''Sapere aude'' ("Dare to Know"). Kant maintained that one ought to think autonomously, free of the dictates of external authority. His work reconciled many of the differences between the rationalist and empiricist traditions of the 18th century. He had a decisive impact on the Romantic and German Idealist philosophies of the 19th century. His work has also been a starting point for many 20th century philosophers.

Kant asserted that, because of the limitations of argumentation in the absence of irrefutable evidence, no one could really know whether there is a God and an afterlife or not. For the sake of society and morality, Kant asserted, people are reasonably justified in believing in them, even though they could never know for sure whether they are real or not. He explained:

The sense of an enlightened approach and the critical method required that "If one cannot prove that a thing ''is,'' he may try to prove that it is ''not.'' And if he succeeds in doing neither (as often occurs), he may still ask whether it is in his ''interest'' to ''accept'' one or the other of the alternatives hypothetically, from the theoretical or the practical point of view. Hence the question no longer is as to whether perpetual peace is a real thing or not a real thing, or as to whether we may not be deceiving ourselves when we adopt the former alternative, but we must ''act'' on the supposition of its being real." The presupposition of God, soul, and freedom was then a practical concern, for "Morality, by itself, constitutes a system, but happiness does not, unless it is distributed in exact proportion to morality. This, however, is possible in an intelligible world only under a wise author and ruler. Reason compels us to admit such a ruler, together with life in such a world, which we must consider as future life, or else all moral laws are to be considered as idle dreams... ."

Kant claimed to have created a "Copernican revolution" in philosophy. This involved two interconnected foundations of his "critical philosophy":

the epistemology of Transcendental Idealism and

the moral philosophy of the autonomy of practical reason.

These teachings placed the active, rational human subject at the center of the cognitive and moral worlds. Kant argued that the rational order of the world as known by science was not just the fortuitous accumulation of sense perceptions.

Conceptual unification and integration is carried out by the mind through concepts or the "categories of the understanding" operating on the perceptual manifold within space and time. The latter are not concepts, but are forms of sensibility that are a priori necessary conditions for any possible experience. Thus the objective order of nature and the causal necessity that operates within it are dependent upon the mind's processes, the product of the rule-based activity which Kant called "synthesis". There is much discussion among Kant scholars on the correct interpretation of this train of thought.

The 'two-world' interpretation regards Kant's position as a statement of epistemological limitation, that we are not able to transcend the bounds of our own mind, meaning that we cannot access the "thing-in-itself". Kant, however, also speaks of the thing in itself or ''transcendental object'' as a product of the (human) understanding as it attempts to conceive of objects in abstraction from the conditions of sensibility. Following this line of thought, some interpreters have argued that the thing in itself does not represent a separate ontological domain but simply a way of considering objects by means of the understanding alone this is known as the two-aspect view.

The notion of the "thing in itself" was much discussed by those who came after Kant. It was argued that since the "thing in itself" was unknowable its existence could not simply be assumed. Rather than arbitrarily switching to an account that was ungrounded in anything supposed to be the "real," as did the German Idealists, another group arose to ask how our (presumably reliable) accounts of a coherent and rule-abiding universe were actually grounded. This new kind of philosophy became known as Phenomenology, and its preeminent spokesman was Edmund Husserl.

With regard to morality, Kant argued that the source of the good lies not in anything outside the human subject, either in nature or given by God, but rather is only the good will itself. A good will is one that acts from duty in accordance with the universal moral law that the autonomous human being freely gives itself. This law obliges one to treat humanity understood as rational agency, and represented through oneself as well as others as an end in itself rather than (merely) as means to other ends the individual might hold.

These ideas have largely framed or influenced all subsequent philosophical discussion and analysis. The specifics of Kant's account generated immediate and lasting controversy. Nevertheless, his theses that the mind itself necessarily makes a constitutive contribution to its knowledge, that this contribution is transcendental rather than psychological, that philosophy involves self-critical activity, that morality is rooted in human freedom, and that to act autonomously is to act according to rational moral principles have all had a lasting effect on subsequent philosophy.

Theory of perception

Kant defines his theory of perception in his influential 1781 work ''The Critique of Pure Reason'', which has often been cited as the most significant volume of metaphysics and epistemology in modern philosophy. Kant maintains that our understanding of the external world had its foundations not merely in experience, but in both experience and a priori concepts, thus offering a non-empiricist critique of rationalist philosophy, which is what he and others referred to as his "Copernican revolution".

Firstly, Kant's distinction between analytic and synthetic propositions:

#Analytic proposition: a proposition whose predicate concept is contained in its subject concept; ''e.g., "All bachelors are unmarried," or, "All bodies take up space."'' #Synthetic proposition: a proposition whose predicate concept is not contained in its subject concept ; ''e.g., "All bachelors are happy," or, "All bodies have weight."

Analytic propositions are true by nature of the meaning of the words involved in the sentence—we require no further knowledge than a grasp of the language to understand this proposition. On the other hand, synthetic statements are those that tell us something about the world. The truth or falsehood of synthetic statements derives from something outside of their linguistic content. In this instance, weight is not a necessary predicate of the body; until we are told the heaviness of the body we do not know that it has weight. In this case, experience of the body is required before its heaviness becomes clear. Before Kant's first Critique, empiricists (cf. Hume) and rationalists (cf. Leibniz) assumed that all synthetic statements required experience in order to be known.

Kant, however, contests this: he claims that elementary mathematics, like arithmetic, is synthetic ''a priori'', in that its statements provide new knowledge, but knowledge that is not derived from experience. This becomes part of his over-all argument for transcendental idealism. That is, he argues that the possibility of experience depends on certain necessary conditions—which he calls ''a priori'' forms—and that these conditions structure and hold true of the world of experience. In so doing, his main claims in the "Transcendental Aesthetic" are that mathematic judgments are synthetic ''a priori'' and in addition, that Space and Time are not derived from experience but rather are its preconditions.

Once we have grasped the concepts of addition, subtraction or the functions of basic arithmetic, we do not need any empirical experience to know that 100 + 100 = 200, and in this way it would appear that arithmetic is in fact analytic. However, that it is analytic can be disproved thus: if the numbers five and seven in the calculation 5 + 7 = 12 are examined, there is nothing to be found in them by which the number 12 can be inferred. Such it is that "5 + 7" and "the cube root of 1,728" or "12" are not analytic because their reference is the same but their sense is not—that the mathematic judgment "5 + 7 = 12" tells us something new about the world. It is self-evident, and undeniably a priori, but at the same time it is synthetic. And so Kant proves a proposition can be synthetic and known a priori.

Kant asserts that experience is based both upon the perception of external objects and a priori knowledge. The external world, he writes, provides those things which we sense. It is our mind, though, that processes this information about the world and gives it order, allowing us to comprehend it. Our mind supplies the conditions of space and time to experience objects. According to the "transcendental unity of apperception", the concepts of the mind (Understanding) and the perceptions or intuitions that garner information from phenomena (Sensibility) are synthesized by comprehension. Without the concepts, intuitions are nondescript; without the intuitions, concepts are meaningless—thus the famous statement, "Thoughts without content are empty, intuitions without concepts are blind."

Categories of the Faculty of Understanding

In studying the work of Kant one must realize that there is a distinction between "understanding" as the general concept (in German, ''das Verstehen'') and the "understanding" as a faculty of the human mind (in German, ''der Verstand'', "the intellect"). In much English language scholarship, the word "understanding" is used in both senses.

Kant deemed it obvious that we have some objective knowledge of the world, such as, say, Newtonian physics. But this knowledge relies on synthetic, ''a priori'' laws of nature, like causality and substance. The problem, then, is how this is possible. Kant’s solution was to reason that the subject must supply laws that make experience of objects possible, and that these laws are the synthetic, ''a priori'' laws of nature which we can know all objects are subject to prior to experiencing them. So to deduce all these laws, Kant examined experience in general, dissecting in it what is supplied by the mind from what is supplied by the given intuitions. This which has just been explicated is commonly called a transcendental reduction.

To begin with, Kant’s distinction between the ''a posteriori'' being contingent and particular knowledge, and the ''a priori'' being universal and necessary knowledge, must be kept in mind. For if we merely connect two intuitions together in a perceiving subject, the knowledge will always be subjective because it is derived ''a posteriori,'' when what is desired is for the knowledge to be objective, that is, for the two intuitions to refer to the object and hold good of it necessarily universally for anyone at anytime, not just the perceiving subject in its current condition. What else is equivalent to objective knowledge besides the ''a priori,'' that is to say, universal and necessary knowledge? Nothing else, and hence before knowledge can be objective, it must be incorporated under an ''a priori'' category of ''the understanding''.

For example, say a subject says, “The sun shines on the stone; the stone grows warm”, which is all he perceives in perception. His judgment is contingent and holds no necessity. But if he says, “The sunshine causes the stone to warm”, he subsumes the perception under the category of causality, which is not found in the perception, and necessarily synthesizes the concept sunshine with the concept heat, producing a necessarily universally true judgment.

To explain the categories in more detail, they are the preconditions of the construction of objects in the mind. Indeed, to even think of the sun and stone presupposes the category of subsistence, that is, substance. For the categories synthesize the random data of the sensory manifold into intelligible objects. This means that the categories are also the most abstract things one can say of any object whatsoever, and hence one can have an ''a priori'' cognition of the totality of all objects of experience if one can list all of them. To do so, Kant formulates another transcendental deduction.

Judgments are, for Kant, the preconditions of any thought. Man thinks via judgments, so all possible judgments must be listed and the perceptions connected within them put aside, so as to make it possible to examine the moments when ''the understanding'' is engaged in constructing judgments. For the categories are equivalent to these moments, in that they are concepts of intuitions in general, so far as they are determined by these moments universally and necessarily. Thus by listing all the moments, one can deduce from them all of the categories.

One may now ask: How many possible judgments are there? Kant believed that all the possible propositions within Aristotle’s syllogistic logic are equivalent to all possible judgments, and that all the logical operators within the propositions are equivalent to the moments of the understanding within judgments. Thus he listed Aristotle’s system in four groups of three: quantity (universal, particular, singular), quality (affirmative, negative, infinite), relation (categorical, hypothetical, disjunctive) and modality (problematic, assertoric, apodeictic). The parallelism with Kant’s categories is obvious: quantity (unity, plurality, totality), quality (reality, negation, limitation), relation (substance, cause, community) and modality (possibility, existence, necessity).

The fundamental building blocks of experience, i.e. objective knowledge, are now in place. First there is the sensibility, which supplies the mind with intuitions, and then there is the understanding, which produces judgments of these intuitions and can subsume them under categories. These categories lift the intuitions up out of the subject’s current state of consciousness and place them within consciousness in general, producing universally necessary knowledge. For the categories are innate in any rational being, so any intuition thought within a category in one mind will necessarily be subsumed and understood identically in any mind. In other words we filter what we see and hear.

Schema

Kant ran into a problem with his theory that the mind plays a part in producing objective knowledge. Intuitions and categories are entirely disparate, so how can they interact? Kant’s solution is the schema: a priori principles by which the transcendental imagination connects concepts with intuitions through time. All the principles are temporally bound, for if a concept is purely a priori, as the categories are, then they must apply for all times. Hence there are principles such as ''substance is that which endures through time'', and ''the cause must always be prior to the effect''.

Moral philosophy

Kant developed his moral philosophy in three works: ''Groundwork of the Metaphysic of Morals'' (1785), ''Critique of Practical Reason'' (1788), and ''Metaphysics of Morals'' (1797) .

In the ''Groundwork'', Kant's method involves trying to convert our everyday, obvious, rational knowledge of morality into philosophical knowledge. The latter two works followed a method of using "practical reason", which is based only upon things about which reason can tell us, and not deriving any principles from experience, to reach conclusions which are able to be applied to the world of experience (in the second part of ''The Metaphysic of Morals'').

Kant is known for his theory that there is a single moral obligation, which he called the "Categorical Imperative", and is derived from the concept of duty. Kant defines the demands of the moral law as "categorical imperatives". Categorical imperatives are principles that are intrinsically valid; they are good in and of themselves; they must be obeyed in all, and by all, situations and circumstances if our behavior is to observe the moral law. It is from the Categorical Imperative that all other moral obligations are generated, and by which all moral obligations can be tested. Kant also stated that the moral means and ends can be applied to the categorical imperative, that rational beings can pursue certain "ends" using the appropriate "means". Ends that are based on physical needs or wants will always give merely hypothetical imperatives. The categorical imperative, however, may be based only on something that is an "end in itself". That is, an end that is a means only to itself and not to some other need, desire, or purpose. He believed that the moral law is a principle of reason itself, and is not based on contingent facts about the world, such as what would make us happy, but to act upon the moral law which has no other motive than "worthiness of being happy". Accordingly, he believed that moral obligation applies to all, but only, rational agents.

A categorical imperative is an unconditional obligation; that is, it has the force of an obligation regardless of our will or desires (Contrast this with hypothetical imperative) In ''Groundwork of the Metaphysic of Morals'' (1785) Kant enumerated three formulations of the categorical imperative which he believed to be roughly equivalent.

Kant believed that if an action is not done with the motive of duty, then it is without moral value. He thought that every action should have pure intention behind it; otherwise it was meaningless. He did not necessarily believe that the final result was the most important aspect of an action, but that how the person felt while carrying out the action was the time at which value was set to the result.

In ''Groundwork of the Metaphysic of Morals'', Kant also posited the "counter-utilitarian idea that there is a difference between preferences and values and that considerations of individual rights temper calculations of aggregate utility", a concept that is an axiom in economics:

Everything has either a ''price'' or a ''dignity''. Whatever has a price can be replaced by something else as its equivalent; on the other hand, whatever is above all price, and therefore admits of no equivalent, has a dignity. But that which constitutes the condition under which alone something can be an end in itself does not have mere relative worth, i.e., price, but an intrinsic worth, i.e., a dignity. (p. 53, italics in original).

A phrase quoted by Kant, which is used to summarize the counter-utilitarian nature of his moral philosophy, is ''Fiat justitia, pereat mundus,'' ("Let justice be done, though the world perish"), which he translates loosely as "Let justice reign even if all the rascals in the world should perish from it". This appears in his 1795 ''Perpetual Peace'' (Zum ewigen Frieden. Ein philosophischer Entwurf.), Appendix 1.

The first formulation

The first formulation (Formula of Universal Law) of the moral imperative "requires that the maxims be chosen as though they should hold as universal laws of nature" . This formulation in principle has as its supreme law the creed "Always act according to that maxim whose universality as a law you can at the same time will" and is the "only condition under which a will can never come into conflict with itself [....]"

One interpretation of the first formulation is called the "universalizability test". An agent's maxim, according to Kant, is his "subjective principle of human actions": that is, what the agent believes is his reason to act. The universalisability test has five steps:

# Find the agent's maxim (i.e., an action paired with its motivation). Take for example the declaration "I will lie for personal benefit". Lying is the action; the motivation is to fulfill some sort of desire. Paired together, they form the maxim. # Imagine a possible world in which everyone in a similar position to the real-world agent followed that maxim. With no exception of one's self. This is in order for you to hold people to the same principle, that is required of yourself. # Decide whether any contradictions or irrationalities arise in the possible world as a result of following the maxim. # If a contradiction or irrationality arises, acting on that maxim is not allowed in the real world. # If there is no contradiction, then acting on that maxim is permissible, and in some instances required.

(For a modern parallel, see John Rawls' hypothetical situation, the original position.)

The second formulation

The second formulation (or Formula of the End in Itself) holds that "the rational being, as by its nature an end and thus as an end in itself, must serve in every maxim as the condition restricting all merely relative and arbitrary ends". The principle dictates that you "[a]ct with reference to every rational being (whether yourself or another) so that it is an end in itself in your maxim", meaning that the rational being is "the basis of all maxims of action" and "must be treated never as a mere means but as the supreme limiting condition in the use of all means, i.e., as an end at the same time".

The third formulation

The third formulation (Formula of Autonomy) is a synthesis of the first two and is the basis for the "complete determination of all maxims". It says "that all maxims which stem from autonomous legislation ought to harmonize with a possible realm of ends as with a realm of nature". In principle, "So act as if your maxims should serve at the same time as the universal law (of all rational beings)", meaning that we should so act that we may think of ourselves as "a member in the universal realm of ends", legislating universal laws through our maxims (that is, a code of conduct), in a "possible realm of ends". None may elevate themselves above the universal law, therefore it is one's duty to follow the maxim(s).

Idea of God

Kant stated the practical necessity for a belief in God in his ''Critique of Practical Reason''. As an idea of pure reason, "we do not have the slightest ground to assume in an absolute manner... the object of this idea...", but adds that the idea of God cannot be separated from the relation of happiness with morality as the "ideal of the supreme good". The foundation of this connection is an intelligible moral world, and "is necessary from the practical point of view"; compare Voltaire: "If God did not exist, it would be necessary to invent him." In the ''Jäsche Logic'' (1800) he wrote "One cannot provide objective reality for any theoretical idea, or prove it, except for the idea of freedom, because this is the condition of the moral law, whose reality is an axiom. The reality of the idea of God can only be proved by means of this idea, and hence only with a practical purpose, i.e., to act as though (''als ob'') there is a God, and hence only for this purpose" (9:93, trans. J. Michael Young, ''Lectures on Logic,'' p. 590-91).

Along with this idea over reason and God, Kant places thought over religion and nature, i.e. the idea of religion being natural or naturalistic. Kant saw reason as natural, and as some part of Christianity is based on reason and morality, as Kant points out this is major in the scriptures, it is inevitable that Christianity is 'natural'. However, it is not 'naturalistic' in the sense that the religion does include supernatural or transcendent belief. Aside from this, a key point is that Kant saw that the Bible should be seen as a source of natural morality no matter whether there is/was any truth behind the supernatural factor, meaning that it is not necessary to know whether the supernatural part of Christianity has any truth to abide by and use the core Christian moral code.

Kant articulates in Book Four some of his strongest criticisms of the organization and practices of Christianity that encourage what he sees as a religion of counterfeit service to God. Among the major targets of his criticism are external ritual, superstition and a hierarchical church order. He sees all of these as efforts to make oneself pleasing to God in ways other than conscientious adherence to the principle of moral rightness in the choice of one's actions. The severity of Kant's criticisms on these matters, along with his rejection of the possibility of theoretical proofs for the existence of God and his philosophical re-interpretation of some basic Christian doctrines, have provided the basis for interpretations that see Kant as thoroughly hostile to religion in general and Christianity in particular (e.g., Walsh 1967).

Kant had exposure to Islam as well and reflected about the role of reason therein.

Idea of freedom

In the ''Critique of Pure Reason'', Kant distinguishes between the transcendental idea of freedom, which as a psychological concept is "mainly empirical" and refers to "the question whether we must admit a power of spontaneously beginning a series of successive things or states" as a real ground of necessity in regard to causality, and the practical concept of freedom as the independence of our will from the "coercion" or "necessitation through sensuous impulses". Kant finds it a source of difficulty that the practical concept of freedom is founded on the transcendental idea of freedom, but for the sake of practical interests uses the practical meaning, taking "no account of... its transcendental meaning", which he feels was properly "disposed of" in the Third Antinomy, and as an element in the question of the freedom of the will is for philosophy "a real stumbling-block" that has "embarrassed speculative reason".

Kant calls practical "everything that is possible through freedom", and the pure practical laws that are never given through sensuous conditions but are held analogously with the universal law of causality are moral laws. Reason can give us only the "pragmatic laws of free action through the senses", but pure practical laws given by reason ''a priori'' dictate "''what ought to be done''".

Aesthetic philosophy

Kant discusses the subjective nature of aesthetic qualities and experiences in ''Observations on the Feeling of the Beautiful and Sublime'', (1764). Kant's contribution to aesthetic theory is developed in the ''Critique of Judgment'' (1790) where he investigates the possibility and logical status of "judgments of taste." In the "Critique of Aesthetic Judgment," the first major division of the ''Critique of Judgment'', Kant used the term "aesthetic" in a manner that is, according to Kant scholar W.H. Walsh, its modern sense. Prior to this, in the ''Critique of Pure Reason'', Kant had, in order to note the essential differences between judgments of taste, moral judgments, and scientific judgments, abandoned the use of the term "aesthetic" as "designating the critique of taste," noting that judgments of taste could never be "directed" by "laws ''a priori''". After A. G. Baumgarten, who wrote ''Aesthetica'' (1750–58), Kant was one of the first philosophers to develop and integrate aesthetic theory into a unified and comprehensive philosophical system, utilizing ideas that played an integral role throughout his philosophy.

In the chapter "Analytic of the Beautiful" of the ''Critique of Judgment'', Kant states that beauty is not a property of an artwork or natural phenomenon, but is instead a consciousness of the pleasure which attends the 'free play' of the imagination and the understanding. Even though it appears that we are using reason to decide that which is beautiful, the judgment is not a cognitive judgment, "and is consequently not logical, but aesthetical" (§ 1). A pure judgement of taste is in fact subjective insofar as it refers to the emotional response of the subject and is based upon nothing but esteem for an object itself: it is a ''disinterested'' pleasure, and we feel that pure judgements of taste, i.e. judgements of beauty, lay claim to universal validity (§§20–22). It is important to note that this universal validity is not derived from a determinate concept of beauty but from ''common sense''. Kant also believed that a judgement of taste shares characteristics engaged in a moral judgement: both are disinterested, and we hold them to be universal. In the chapter "Analytic of the Sublime" Kant identifies the sublime as an aesthetic quality which, like beauty, is subjective, but unlike beauty refers to an indeterminate relationship between the faculties of the imagination and of reason, and shares the character of moral judgments in the use of reason. The feeling of the sublime, itself divided into two distinct modes (the mathematical sublime and the dynamical sublime), describe two subjective moments both of which concern the relationship of the faculty of the imagination to reason. The mathematical sublime is situated in the failure of the imagination to comprehend natural objects which appear boundless and formless, or which appear "absolutely great" (§ 23–25). This imaginative failure is then recuperated through the pleasure taken in reason's assertion of the concept of infinity. In this move the faculty of reason proves itself superior to our fallible sensible self (§§ 25–26). In the dynamical sublime there is the sense of annihilation of the sensible self as the imagination tries to comprehend a vast might. This power of nature threatens us but through the resistance of reason to such sensible annihilation, the subject feels a pleasure and a sense of the human moral vocation. This appreciation of moral feeling through exposure to the sublime helps to develop moral character.

Kant had developed the distinction between an object of art as a material value subject to the conventions of society and the transcendental condition of the judgment of taste as a "refined" value in the propositions of his ''Idea of A Universal History'' (1784). In the Fourth and Fifth Theses of that work he identified all art as the "fruits of unsociableness" due to men's "antagonism in society", and in the Seventh Thesis asserted that while such material property is indicative of a civilized state, only the ideal of morality and the universalization of refined value through the improvement of the mind of man "belongs to culture".

Political philosophy

In ''Perpetual Peace: A Philosophical Sketch'' Kant listed several conditions that he thought necessary for ending wars and creating a lasting peace. They included a world of constitutional republics. His classical republican theory was extended in the first part of Metaphysics of Morals - published separately earlier in 1790 as ''Science of Right''.

He opposed "democracy," which at his time meant direct democracy, believing that majority rule posed a threat to individual liberty. He stated, "...democracy is, properly speaking, necessarily a despotism, because it establishes an executive power in which 'all' decide for or even against one who does not agree; that is, 'all,' who are not quite all, decide, and this is a contradiction of the general will with itself and with freedom." As most writers at the time he distinguished three forms of government i.e. democracy, aristocracy, and monarchy with mixed government as the most ideal form of it.

Anthropology

Kant lectured on anthropology for over 25 years. His ''Anthropology from a Pragmatic Point of View'' was published in 1798. (This was the subject of Michel Foucault's doctoral dissertation.) Kant's Lectures on Anthropology were published for the first time in 1997 in German. The former was translated into English and published by the Cambridge Texts in the History of Philosophy series in 2006.

Influence

Kant's influence on Western thought has been profound. Over and above his influence on specific thinkers, Kant changed the framework within which philosophical inquiry has been carried out. He accomplished a paradigm shift: very little philosophy is now carried out as an extension, or in the style of pre-Kantian philosophy. This shift consists in several closely related innovations that have become axiomatic, in philosophy itself and in the social sciences and humanities generally:

Kant's "Copernican revolution", that placed the role of the human subject or knower at the center of inquiry into our knowledge, such that it is impossible to philosophize about things as they are independently of us or of how they are for us;

his invention of critical philosophy, that is of the notion of being able to discover and systematically explore possible inherent limits to our ability to know through philosophical reasoning;

his creation of the concept of "conditions of possibility", as in his notion of "the conditions of possible experience" that is that things, knowledge, and forms of consciousness rest on prior conditions that make them possible, so that to understand or know them we have to first understand these conditions;

his theory that objective experience is actively constituted or constructed by the functioning of the human mind;

his notion of moral autonomy as central to humanity;

his assertion of the principle that human beings should be treated as ends rather than as means.

Some or all of these Kantian ideas can be seen in schools of thought as different from one another as German Idealism, Marxism, positivism, phenomenology, existentialism, critical theory, linguistic philosophy, structuralism, post-structuralism, and deconstructionism.

Historical influence

During his own life, there was much critical attention paid to his thought . He did have a positive influence on Reinhold, Fichte, Schelling, Hegel, and Novalis during the 1780s and 1790s. The school of thinking known as German Idealism developed from his writings. The German Idealists Fichte and Schelling, for example, tried to bring traditional "metaphysically" laden notions like "the Absolute," "God," or "Being" into the scope of Kant's critical thought. In so doing, the German Idealists tried to reverse Kant's view that we cannot know that which we cannot observe.

Hegel was one of his first major critics. In response to what he saw as Kant's abstract and formal account, Hegel brought about an ethic focused on the "ethical life" of the community. But Hegel's notion of "ethical life" is meant to subsume, rather than replace, Kantian ethics. And Hegel can be seen as trying to defend Kant's idea of freedom as going beyond finite "desires," by means of reason. Thus, in contrast to later critics like Nietzsche or Russell, Hegel shares some of Kant's most basic concerns.

Many British Catholic writers, notably G. K. Chesterton and Hilaire Belloc, seized on Kant and promoted his work. This was with a view to restoring support for a belief in God. Reaction against this, and an attack on Kant's use of language, is found in Ronald Englefield's article, reprinted in Englefield These criticisms of Kant were common in the realist views of the new positivism.

Arthur Schopenhauer was strongly influenced by Kant's transcendental idealism. He, like G. E. Schulze, Jacobi and Fichte before him, was critical of Kant's theory of the thing in itself. Things in themselves, they argued, are neither the cause of what we observe nor are they completely beyond our access. Ever since the first ''Critique of Pure Reason'' philosophers have been critical of Kant's theory of the thing in itself. Many have argued, if such a thing exists beyond experience then one cannot posit that it affects us causally, since that would entail stretching the category 'causality' beyond the realm of experience. For a review of this problem and the relevant literature see ''The Thing in Itself and the Problem of Affection'' in the revised edition of Henry Allison's ''Kant's Transcendental Idealism''. For Schopenhauer things in themselves do not exist outside the non-rational will. The world, as Schopenhauer would have it, is the striving and largely unconscious will.

With the success and wide influence of Hegel's writings, Kant's influence began to wane, though there was in Germany a movement that hailed a return to Kant in the 1860s, beginning with the publication of ''Kant und die Epigonen'' in 1865 by Otto Liebmann. His motto was "Back to Kant", and a re-examination of his ideas began (See Neo-Kantianism). During the turn of the 20th century there was an important revival of Kant's theoretical philosophy, known as the Marburg School, represented in the work of Hermann Cohen, Paul Natorp, Ernst Cassirer, and anti-Neo-Kantian Nicolai Hartmann.

Kant's notion of "Critique" or criticism has been quite influential. The Early German Romantics, especially Friedrich Schlegel in his "Athenaeum Fragments", used Kant's self-reflexive conception of criticism in their Romantic theory of poetry. Also in Aesthetics, Clement Greenberg, in his classic essay "Modernist Painting", uses Kantian criticism, what Greenberg refers to as "immanent criticism", to justify the aims of Abstract painting, a movement Greenberg saw as aware of the key limitiaton—flatness—that makes up the medium of painting. French philosopher Michel Foucault was also greatly influenced by Kant's notion of "Critique" and wrote several pieces on Kant for a re-thinking of the Enlightenment as a form of "critical thought". He went so far as to classify his own philosophy as a "critical history of modernity, rooted in Kant".

Kant believed that mathematical truths were forms of synthetic a priori knowledge, which means they are necessary and universal, yet known through intuition. Kant’s often brief remarks about mathematics influenced the mathematical school known as intuitionism, a movement in philosophy of mathematics opposed to Hilbert’s formalism, and the logicism of Frege and Bertrand Russell.

Influence on modern thinkers

With his ''Perpetual Peace'', Kant is considered to have foreshadowed many of the ideas that have come to form the democratic peace theory, one of the main controversies in political science.

The Kantian paradigm shift in philosophy and metaphysics has been sustained. Some British and American philosophers trace their intellectual origins to Hume: however, Kant acknowledged Hume as awakening him from his 'dogmatic slumbers', and his work articulated and clarified the issues looked at by Hume. (See The silent decade section, above).

Prominent recent Kantians include the British philosopher P. F. Strawson, the American philosophers Wilfrid Sellars and Christine Korsgaard.

Due to the influence of Strawson and Sellars, among others, there has been a renewed interest in Kant's view of the mind. Central to many debates in philosophy of psychology and cognitive science is Kant's conception of the unity of consciousness.

Kant's work on mathematics and synthetic a priori knowledge is also cited by theoretical physicist Albert Einstein as an early influence on his intellectual development.

Jürgen Habermas and John Rawls are two significant political and moral philosophers whose work is strongly influenced by Kant's moral philosophy. They have each argued against relativism, supporting the Kantian view that universality is essential to any viable moral philosophy.

Ayn Rand was a critic of Kant. She referred to him as a "monster" and "the most evil man in history". Rand was strongly opposed to the view that reason is unable to know reality "as it is in itself", which she ascribed to Kant, and she considered her philosophy to be the "exact opposite" of Kant's on "every fundamental issue".

Kant's influence also has extended to the social and behavioral sciences, as in the sociology of Max Weber, the psychology of Jean Piaget, and the linguistics of Noam Chomsky. Because of the thoroughness of the Kantian paradigm shift, his influence extends to thinkers who neither specifically refer to his work nor use his terminology.

Tomb and statue

Kant's tomb is today in a mausoleum adjoining the northeast corner of Königsberg Cathedral in what is now known as Kaliningrad, Russia. The mausoleum was constructed by the architect Friedrich Lahrs and was finished in 1924 in time for the bicentenary of Kant's birth. Originally, Kant was buried inside the cathedral, but in 1880 his remains were moved outside and placed in a neo-Gothic chapel adjoining the northeast corner of the cathedral. Over the years, the chapel became dilapidated before it was demolished to make way for the mausoleum, which was built on the same spot, where it is today.

The tomb and its mausoleum are some of the few artifacts of German times preserved by the Soviets after they conquered and annexed the city. Today, many newlyweds bring flowers to the mausoleum.

A replica of the statue of Kant that stood in German times in front of the main University of Königsberg building was donated by a German entity in the early 1990s and placed in the same grounds.

After the expulsion of Königsberg's German population at the end of World War II, the historical University of Königsberg where Kant taught was replaced by the Russian-speaking "Kaliningrad State University", which took up the campus and surviving buildings of the historic German university. In 2005, that Russian-speaking university was renamed Immanuel Kant State University of Russia in honour of Kant. The change of name was announced at a ceremony attended by President Vladimir Putin of Russia and Chancellor Gerhard Schröder of Germany, and the university further formed a Kant Society, dedicated to the study of Kantianism.

List of works

(1746) ''Thoughts on the True Estimation of Vital Forces'' (''Gedanken von der wahren Schätzung der lebendigen Kräfte'')

(1755) ''A New Explanation of the First Principles of Metaphysical Knowledge'' (''Neue Erhellung der ersten Grundsätze metaphysischer Erkenntnisse''; Doctoral Thesis: ''Principiorum primorum cognitionis metaphysicae nova dilucidatio'')

(1755) ''Universal Natural History and Theory of Heaven'' (''Allgemeine Naturgeschichte und Theorie des Himmels'')

(1756) ''Monadologia Physica''

(1762) ''The False Subtlety of the Four Syllogistic Figures'' (''Die falsche Spitzfindigkeit der vier syllogistischen Figuren'')

(1763) ''The Only Possible Argument in Support of a Demonstration of the Existence of God'' (''Der einzig mögliche Beweisgrund zu einer Demonstration des Daseins Gottes'')

(1763) ''Attempt to Introduce the Concept of Negative Magnitudes into Philosophy'' (''Versuch den Begriff der negativen Größen in die Weltweisheit einzuführen'')

(1764) ''Observations on the Feeling of the Beautiful and Sublime'' (''Beobachtungen über das Gefühl des Schönen und Erhabenen'')

(1764) ''Essay on the Illness of the Head'' (''Über die Krankheit des Kopfes'')

(1764) ''Inquiry Concerning the Distinctness of the Principles of Natural Theology and Morality'' (the ''Prize Essay'') (''Untersuchungen über die Deutlichkeit der Grundsätze der natürlichen Theologie und der Moral'')

(1766) ''Dreams of a Spirit Seer'' (''On Emmanuel Swedenborg'') (''Träume eines Geistersehers'')

(1770) ''Inaugural Dissertation'' (''De mundi sensibilis atque intelligibilis forma et principiis'')

(1775) ''On the Different Races of Man'' (''Über die verschiedenen Rassen der Menschen'')

(1781) First edition of the ''Critique of Pure Reason'' (''Kritik der reinen Vernunft'' ) (1783) "''Prolegomena to any Future Metaphysics''" (''Prolegomena zu einer jeden künftigen Metaphysik'') (1784) "An Answer to the Question: What Is Enlightenment?" (''Beantwortung der Frage: Was ist Aufklärung?'' )

(1784) "Idea for a Universal History with a Cosmopolitan Purpose" (''Idee zu einer allgemeinen Geschichte in weltbürgerlicher Absicht'')

(1785) ''Groundwork of the Metaphysics of Morals'' (''Grundlegung zur Metaphysik der Sitten'')

(1786) ''Metaphysical Foundations of Natural Science'' (''Metaphysische Anfangsgründe der Naturwissenschaft'')

(1786) ''Conjectural Beginning of Human History''

(1787) Second edition of the ''Critique of Pure Reason'' (''Kritik der reinen Vernunft'' ) (1788) ''Critique of Practical Reason'' (''Kritik der praktischen Vernunft'' ) (1790) ''Critique of Judgement'' (''Kritik der Urteilskraft'' ) (1790) ''The Science of Right'' (1793) ''Religion within the Limits of Reason Alone'' (''Die Religion innerhalb der Grenzen der bloßen Vernunft'')

(1793) ''On the Old Saw: That may be right in theory, but it won't work in practice'' ''(Über den Gemeinspruch: Das mag in der Theorie richtig sein, taugt aber nicht für die Praxis)''

(1795) ''Perpetual Peace'' (''Zum ewigen Frieden'' )

(1797) ''Metaphysics of Morals'' (''Metaphysik der Sitten'')

(1798) ''Anthropology from a Pragmatic Point of View'' (''Anthropologie in pragmatischer Hinsicht'')

(1798) ''The Contest of Faculties'' (''Der Streit der Fakultäten'' )

(1800) ''Logic'' (''Logik'')

(1803) ''On Pedagogy'' (''Über Pädagogik'')

(1804) ''Opus Postumum''

(1817) ''Lectures on Philosophical Theology'' (''Immanuel Kants Vorlesungen über die philosophische Religionslehre'' edited by K. H. L. Pölitz). [The English edition of A. W. Wood & G. M. Clark (Cornell, 1978) is based on Pölitz' second edition, 1830, of these lectures.]

See also

''Aenesidemus (book)''

Kant Russian State University

List of liberal theorists

On Vision and Colors

Political philosophy of Immanuel Kant

Rechtsstaat

Rule according to higher law

Criticism

Schopenhauer's criticism of the Kantian philosophy

Schopenhauer's criticism of Kant's Groundwork of the Metaphysic of Morals

Schopenhauer's criticism of Kant's schemata

References and further reading

Any suggestion of further reading on Kant has to take cognizance of the fact that his work has dominated philosophy like no other figure after him. Nevertheless, several guideposts can be made out. In Germany, the most important contemporary interpreter of Kant and the movement of German Idealism which he began is Dieter Henrich, who has some work available in English. P.F. Strawson's "The Bounds of Sense" (1969) played a significant role in determining the contemporary reception of Kant in England and America. More recent interpreters of note in the English-speaking world include Lewis White Beck, Jonathan Bennett, Henry Allison, Paul Guyer, Christine Korsgaard, Stephen Palmquist, Robert B. Pippin, Roger Scruton, Rudolf Makkreel, and Béatrice Longuenesse.

General introductions to his thought

Scruton, Roger. ''Kant: A Very Short Introduction''. Oxford University Press, 2001. ISBN 0192801996 (Provides a brief account of his life, and a lucid introduction to the three major critiques.)

Broad C. D. ''Kant: An Introduction''. Cambridge University Press, 1978. ISBN 0-521-21755-5, ISBN 0-521-29265-4

Gardner, Sebastian ''Kant and the Critique of Pure Reason''. Routledge, 1999. ISBN 0-415-11909-X

Martin, Gottfried. ''Kant's Metaphysics and Theory of Science''. Greenwood Press, 1955 ISBN 978-0-8371-7154-8 (This study elucidates Kant's most fundamental concepts in their historical context.)

Perez, D. O. Kant e o problema da significação. Curitiba: Editora Champagnat, 2008.

Palmquist, Stephen. Kant's System of Perspectives: An architectonic interpretation of the Critical philosophy. University Press of America, 1993. ISBN 0-8191-8927-8

Seung, T. K. 2007. ''Kant: Guide for the Perplexed''. London: Continuum. ISBN 0-8264-8580-4

Uleman, Jennifer. ''An Introduction to Kant's Moral Philosophy''. Cambridge University Press, 2010. ISBN 978-0-521-13644-0

Biography and historical context

Beck, Lewis White. ''Early German Philosophy: Kant and his Predecessors.'' Harvard University Press, 1969. ''Survey of Kant's intellectual background''

Beiser, Frederick C. ''The Fate of Reason: German Philosophy from Kant to Fichte.'' Harvard University Press, 1987.

Beiser, Frederick C. ''German Idealism: The Struggle against Subjectivism, 1781-1801.'' Harvard University Press, 2002

Cassirer, Ernst. ''Kant's Life and Thought.'' Translation of ''Kants Leben und Lehre''. Trans., Jame S. Haden, intr. Stephan Körner. New Haven, CT: Yale University Press, 1981.

Chamberlain, Houston Stewart. ''Immanuel Kant a study and a comparison with Goethe, Leonardo da Vinci, Bruno, Plato and Descartes'', the authorised translation from the German by Lord Redesdale, with his 'Introduction', The Bodley Head, London, 1914, (2 volumes).

Gulyga, Arsenij. ''Immanuel Kant: His Life and Thought''. Trans., Marijan Despaltović. Boston: Birkhäuser, 1987.

Johnson, G.R. ed. ''Kant on Swedenborg. Dreams of a Spirit-Seer and Other Writings''. Swedenborg Foundation, 2002. (New translation and analysis, many supplementary texts)

Kuehn, Manfred. ''Kant: A Biography.'' Cambridge University Press, 2001. ISBN 0-521-49704-3. ''Now the standard biography of Kant in English''

Lehner, Ulrich L., Kants Vorsehungskonzept auf dem Hintergrund der deutschen Schulphilosophie und -theologie (Leiden: 2007) (Kant's Concept of Providence and its background in German School Philosophy & Theology)

Pinkard, Terry. ''German philosophy, 1760-1860: The Legacy of Idealism.'' Cambridge, 2002.

Sassen, Brigitte. ed. ''Kant's Early Critics: The Empiricist Critique of the Theoretical Philosophy'', 2000.

Collections of essays

Guyer, Paul. ed. ''The Cambridge Companion to Kant.'' Cambridge University Press, 1992. ISBN 0-521-36587-2, ISBN 0-521-36768-9. ''Excellent collection of papers that covers most areas of Kant's thought''

Förster, Eckart ed. "Kant's Transcendental Deductions: The Three 'Critiques' and the 'Opus Postumum.'" Stanford: Stanford University Press, 1989. ''Includes an important essay by Dieter Henrich'

Cohen, Ted and Paul Guyer eds. ''Essays in Kant's Aesthetics. Chicago: University of Chicago Press, 1982. ''Essays on Kant's Critique of Judgment''

Firestone, Chris L. and Stephen Palmquist (eds.). ''Kant and the New Philosophy of Religion''. Indiana University Press, 2006. ISBN 0-253-21800-4

Mohanty, J.N. and Robert W. Shahan. eds. ''Essays on Kant's Critique of Pure Reason.'' Norman: University of Oklahoma Press, 1982. ISBN 0-8061-1782-6

Phillips, Dewi et al. ''Kant and Kierkegaard on Religion.'' Palgrave Macmillian, 2000, ISBN 0-312-23234-9 ''Collection of essays about Kantian religion and its influence on Kierkegaardian and contemporary philosophy of religion.''

''Proceedings of the International Kant Congresses.'' Several Congresses (numbered) edited by various publishers.

Theoretical philosophy

Allison, Henry. ''Kant’s Transcendental Idealism.'' New Haven: Yale University Press, 1983, 2004. ISBN 0-300-03629-9, ISBN 0-300-03002-9. ''Very influential defense of Kant's idealism, recently revised''

Ameriks, Karl. ''Kant's Theory of Mind: An Analysis of the Paralogisms of Pure Reason.'' Oxford: Clarendon Press, 1982. ''One of the first detailed studies of the Dialectic in English''

Banham, Gary. ''Kant's Transcendental Imagination'' London and New York: Palgrave Macmillan, 2006: "has an unrivalled ability to make Kant our contemporary and to show that the critical philosophy still contains untapped resources and even surprises".

Dottarelli Luciano, ''Kant e la metafisica come scienza'', Roma, Erre Emme, 1995. ISBN 88-85378-75-7

Farias, Vanderlei de Oliveira. Kants Realismus und der Aussenweltskeptizismus. OLMS. Hildesheim, Zürich, New York. 2006.

Deleuze, Gilles. ''Kant's Critical Philosophy''. Trans., Hugh Tomlinson and Barbara Habberjam. University of Minnesota Press, 1984. ISBN 0-8166-1341-9, ISBN 0-8166-1436-9

Gram, Moltke S. ''The Transcendental Turn: The Foundation of Kant's Idealism.'' Gainesville: University Presses of Florida, 1984. ISBN 0-8130-0787-9

Greenberg, Robert. Kant's Theory of A Priori Knowledge, Penn State Press, 2001 ISBN 0-271-02083-0

Guyer, Paul. ''Kant and the Claims of Knowledge.'' Cambridge, UK: Cambridge University Press, 1987. ''Modern defense of the view that Kant's theoretical philosophy is a "patchwork" of ill-fitting arguments''

Heidegger, Martin. ''Kant and the Problem of Metaphysics'', Indiana University Press, 1997. ISBN 0-253-21067-4

Henrich, Dieter. ''The Unity of Reason: Essays on Kant’s Philosophy.'' Edited and with an introduction by Richard L. Velkley; translated by Jeffrey Edwards... [et al.]. Harvard University Press, 1994. ISBN 0-674-92905-5

Kemp Smith, Norman. ''A Commentary to Kant's ‘Critique of Pure Reason''. London: Macmillan, 1930. ''Somewhat dated, but influential commentary on the first Critique, recently reprinted''

Kitcher, Patricia. ''Kant's Transcendental Psychology.'' New York: Oxford University Press, 1990.

Longuenesse, Béatrice. ''Kant and the Capacity to Judge.'' Princeton University Press, 1998. ISBN 0-691-04348-5. ''Argues that the notion of judgment provides the key to understanding the overall argument of the first Critique''

Melnick, Arthur. ''Kant's Analogies of Experience.'' Chicago: University of Chicago Press, 1973. ''Important study of Kant's Analogies, including his defense of the principle of causality''

Sgarbi, Marco. La Kritik der reinen Vernunft nel contesto della tradizione logica aristotelica, Hildesheim, Olms 2010

Paton, H. J. ''Kant’s Metaphysic of Experience: A Commentary on the First Half of the Kritik der reinen Vernunft''. Two volumes. London: Macmillan, 1936. ''Extensive study of Kant's theoretical philosophy''

Pippin, Robert B.. ''Kant's Theory of Form: An Essay on the Critique of Pure Reason.'' New Haven: Yale University Press, 1982. ''Influential examination of the formal character of Kant's work''

Sala, Giovanni. Kant, Lonergan und der christliche Glaube (Nordhausen: Bautz, 2005), ed. by Ulrich L. Lehner and Ronald K. Tacelli

Schopenhauer, Arthur. ''Die Welt als Wille und Vorstellung. Erster Band. Anhang. Kritik der Kantischen Philosophie''. F. A. Brockhaus, Leipzig 1859 (In English: Arthur Schopenhauer, New York: Dover Press, Volume I, Appendix, "Criticism of the Kantian Philosophy", ISBN 0-486-21761-2)

Seung, T. K. ''Kant's Transcendental Logic''. New Haven: Yale University Press, 1969.

Strawson, P.F. ''The Bounds of Sense: an essay on Kant's Critique of Pure Reason.'' Routledge, 1989. ''Work that revitalized the interest of contemporary analytic philosophers in Kant''

Wolff, Robert Paul. ''Kant's theory of mental activity: A commentary on the transcendental analytic of the Critique of Pure Reason.'' Cambridge, Mass.: Harvard University Press, 1963. ''Detailed and influential commentary on the first part of the Critique of Pure Reason''

Yovel, Yirmiyahu. ''Kant and the Philosophy of History.'' Princeton: Princeton University Press, 1989.

Practical philosophy

Allison, Henry, ''Kant's theory of freedom'' Cambridge University Press 1990.

Banham, Gary. ''Kant's Practical Philosophy: From Critique to Doctrine'' Palgrave Macmillan, 2003.

Koorsgaard, Christine M. ''The Sources of Normativity'' Cambridge University Press, 1996.

Michalson, Gordon E. ''Fallen Freedom: Kant on Radical Evil and Moral Regeneration.'' Cambridge University Press, 1990.

Michalson, Gordon E. ''Kant and the Problem of God.'' Blackwell Publishers, 1999.

Paton, H. J. ''The Categorical Imperative; a study in Kant's moral philosophy'' University of Pennsylvania Press 1971.

Rawls, John. ''Lectures on the History of Moral Philosophy. '' Cambridge, 2000.

Seung, T.K. ''Kant's Platonic Revolution in Moral and Political Philosophy''. Johns Hopkins, 1994.

Wolff, Robert Paul. ''The Autonomy of Reason: A Commentary on Kant's Groundwork of the Metaphysic of Morals.'' New York: HarperCollins, 1974. ISBN 0-06-131792-6.

Wood, Allen. ''Kant's Ethical Thought'' New York: Cambridge University Press: 1999.

Aesthetics

Allison, Henry. ''Kant's Theory of Taste: A Reading of the Critique of Aesthetic Judgment''. Cambridge, UK: Cambridge University Press, 2001.

Banham, Gary. ''Kant and the Ends of Aesthetics''. London and New York: Macmillan Press, 2000.

Crawford, Donald. ''Kant's Aesthetic Theory''. Wisconsin, 1974.

Guyer, Paul. ''Kant and the Claims of Taste''. Cambridge, MA and London, 1979.

Hammermeister, Kai. ''The German Aesthetic Tradition''. Cambridge University Press, 2002.

''Immanuel Kant'' entry in Kelly, Michael (Editor in Chief) (1998) ''Encyclopedia of Aesthetics''. New York, Oxford, Oxford University Press.

Makkreel, Rudolf, ''Imagination and Interpretation in Kant''. Chicago, 1990.

McCloskey, Mary. ''Kant's Aesthetic''. SUNY, 1987.

Schaper, Eva. ''Studies in Kant's Aesthetics''. Edinburgh, 1979.

Zammito, John H. ''The Genesis of Kant's Critique of Judgment''. Chicago and London: Chicago University Press, 1992.

Zupancic, Alenka. ''Ethics of the Real: Kant and Lacan''. Verso, 2000.

Philosophy of religion

Palmquist, Stephen. Kant's Critical Religion: Volume Two of ''Kant's System of Perspectives''. Ashgate, 2000. ISBN 0-7546-1333-X

Perez, D. O. . Religión, Política y Medicina en Kant: El Conflicto de las Proposiciones. Cinta de Moebio. Revista de Epistemologia de Ciencias Sociales., v. 28, p. 91-103, 2007. Uchile.cl

Other work

Braver, Lee. ''A Thing of This World: a History of Continental Anti-Realism''. Northwestern University Press: 2007. ISBN 978-0-8101-2380-9 (This study covers Kant and his contribution to the history of Continental Anti-Realism)

Caygill, Howard. ''A Kant Dictionary''. Oxford, UK; Cambridge, Mass., USA: Blackwell Reference, 1995. ISBN 0-631-17534-2, ISBN 0-631-17535-0

Derrida, Jacques. ''Mochlos; or, The Conflict of the Faculties''. Columbia University, 1980.

Mosser, Kurt. ''Necessity and Possibility; The Logical Strategy of Kant's Critique of Pure Reason''. Catholic University of America Press, 2008. ISBN 978-0-8132-1532-7

Perez, D. O. . Os significados dos conceitos de hospitalidade em Kant e a problemática do estrangeiro. Revista Philosophica (Chile), v. 31, p. 43-53, 2007. Também em Konvergencias, 2007, nro. 15. UCV.cl, Konvergencias.net

Perez, D. O. A loucura como questão semântica:uma interpretação kantiana. Trans/Form/Ação, São Paulo, 32(1): 95-117, 2009. Scielo.br

Contemporary philosophy with a Kantian influence

Herman, Barbara. ''The Practice of Moral Judgement''. Harvard University Press, 1993.

Korsgaard, Christine. ''Creating the Kingdom of Ends.'' Cambridge; New York, NY, USA: Cambridge University Press, 1996. ISBN 0-521-49644-6, ISBN 0-521-49962-3 (pbk.) ''Not a commentary, but a defense of a broadly Kantian approach to ethics''

McDowell, John. ''Mind and World.'' Harvard University Press, 1994. ISBN 0-674-57609-8. ''Offers a Kantian solution to a dilemma in contemporary epistemology regarding the relation between mind and world''

Parfit, Derek. Climbing the Mountain

Pinker, Steven. ''The Stuff of Thought.'' Viking Press, 2007. ISBN 978-0-670-06327-7. ''Chapter 4 - Cleaving the Air - discusses Kant's anticipation of modern cognitive science''

Wood, Allen. ''Kant's Ethical Thought.'' Cambridge; New York, NY, USA: Cambridge University Press, 1999. ISBN 0-521-64836-X. ''Comprehensive, in depth study of Kant's ethics, with emphasis on formula of humanity as most accurate formulation of the categorical imperative (according to similar arguments as Korsgaard)''

External links

(More German works at Wikisource)

(More German works at Project Gutenberg)

(More English works at The University of Adelaide Library)

Digital edition of Kant's Collected Works, vols. 1-23 in German

Works by Immanuel Kant in audio format from LibriVox

Stephen Palmquist's Glossary of Kantian Terminology

Kant's Categories as grammatical reifications

Kant's Ethical Theory Kantian ethics explained, applied and evaluated

Kant & Ethics Extensive links and discussions from Lawrence Hinman at University of San Diego

Notes on Deontology A conveniently brief survey of Kant's deontology

Kant on the Web on Stephen Palmquist's website

Kant Links

Kant Can: Allen Wood Clears A Path To Kants Complex Philosophies

Kant's Epistemology and Metaphysics according to the Friesian school

German Idealist Foundations of Durkheim's Sociology and Teleology of Knowledge

Several Kant's works in clickable pdf

Routledge Encyclopedia of Philosophy (14 sections on Kant)

International Kant Interview - 2004

Readable versions of Prolegomena, Groundwork for the Metaphysic of Morals, Critique of Pure Reason, and Metaphysical Foundations of Natural Science (J. Bennett translations)

Kant's moral philosophy and the question of pre-emptive war, Revue Sens Public

Kant in the Classroom background information for Kant's lectures

Works: text, concordances and frequency list

Kant's Death Mask

The ''Stanford Encyclopedia of Philosophy'' has several entries on Kant:

* Immanuel Kant

* Kant's Philosophical Development

* Kant's Critique of Metaphysics

* Kant's Theory of Judgment

* Kant's Philosophy of Science

* Kant's View of the Mind and Consciousness of Self

* Kant's Aesthetics and Teleology

* Kant's Philosophy of Religion

* Kant's Moral Philosophy

* Kant and Leibniz

Footnotes

Category:1724 births Category:1804 deaths Kantianism Kantian philosophers Category:18th-century German people Category:18th-century Prussian people Category:18th-century philosophers Category:Enlightenment philosophers Category:Christian philosophers Category:Continental philosophers Category:Deontological ethics Category:Epistemologists Category:German-language philosophers Category:German idealism Category:German philosophers Category:German anthropologists Category:Idealists Category:German logicians Category:Philosophers of art Category:Philosophers of law Category:Philosophers of science Category:Philosophy of sexuality Category:Moral philosophers Category:Natural philosophers Category:Ontologists Category:Political theorists Category:Members of the Prussian Academy of Sciences Category:German Lutherans Category:German people of Scottish descent Category:People of Baltic German descent Category:People from East Prussia Category:People from Königsberg Category:People from Kaliningrad Category:University of Königsberg faculty Category:University of Königsberg alumni

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Coordinates	67°52′34″N178°44′20″N
Color	#B0C4DE
Name	Manuel de Landa
Birth date	1952
Birth place	Mexico City, Mexico
Main interests	MorphogenesisNonlinear dynamics }}

Manuel De Landa, (born 1952 in Mexico City), is a writer, artist and philosopher who has lived in New York since 1975. He is presently the Gilles Deleuze Chair of Contemporary Philosophy and Science at the European Graduate School in Saas-Fee, Switzerland; a lecturer at the Canisius College in Buffalo, New York; a lecturer at the University of Pennsylvania School of Design in Philadelphia, Pennsylvania; and an adjunct professor at the Pratt Institute School of Architecture in Brooklyn, New York. He was previously an Adjunct Associate Professor in the Graduate School of Architecture, Planning and Preservation at Columbia University. De Landa has a BFA from New York's School of Visual Arts.

He is the author of ''War in the Age of Intelligent Machines'' (1991), ''A Thousand Years of Nonlinear History'' (1997), ''Intensive Science and Virtual Philosophy'' (2002) and ''A New Philosophy of Society: Assemblage Theory and Social Complexity'' (2006). He has published many articles and essays and lectured extensively in Europe and in the United States. His work focuses on the theories of the French philosopher Gilles Deleuze on one hand, and modern science, self-organizing matter, artificial life and intelligence, economics, architecture, chaos theory, history of science, nonlinear dynamics, cellular automata on the other.

De Landa became a principal figure in the "new materialism" based on his application of Deleuze's realist ontology. His universal research into "morphogenesis" - the production of the semi-stable structures out of material flows that are constitutive of the natural and social world - has been of interest to theorists across many academic and professional disciplines.

Alongside his intellectual work, De Landa made several short Super 8 and 16mm films in the 1970s and early 1980s. He pulled them from circulation after the original negatives were lost. In 2011, Anthology Film Archives restored and reissued them. Cited by filmmaker Nick Zedd in his Cinema of Transgression Manifesto, De Landa associated with many of the experimental and art filmmakers of this New York based movement. Much of De Landa's film work is inspired by his interest in philosophy and critical theory; one of his best known films, ''Raw Nerves'', has been described as a 'Lacanian thriller' by at least one critic.

His latest book (as of March 2011) is ''Philosophy and Simulation: The Emergence of Synthetic Reason'', which explores simulations of emergence in systems of different scales, from the atomic to the social.

Books

''War in the Age of Intelligent Machines'' (1991)

''A Thousand Years of Nonlinear History'' (1997)

''Intensive Science and Virtual Philosophy'' (2002)

''A New Philosophy of Society: Assemblage Theory and Social Complexity'' (2006)

''Deleuze: History and Science'' (2010)

''Philosophy & Simulation: The Emergence of Synthetic Reason'' (2011)

See also

Gilles Deleuze

Noosphere

Realism

Wargaming

External links

Manuel de Landa Faculty profile at European Graduate School EGS. Biography, bibliography, photos, quotes and video lectures.

Manuel DeLanda Annotated Bibliography with links to articles

Various texts

http://www.canisius.edu/topos/delanda.asp

Interview

Interview on ''Ctheory''

Other interview by Paul Miller

"Markets and antimarkets in the world economy" by DeLanda

Notes

Category:1952 births Category:Living people Category:Mexican philosophers Category:People from Buffalo, New York Category:Columbia University faculty Category:European Graduate School faculty Category:Cellular automatists

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