Commensurability (philosophy of science)

Commensurability is a concept, in philosophy of science, whereby scientific theories are commensurable if scientists can discuss using a shared nomenclature that allows direct comparison of theories to determine which theory is more valid or useful. On the other hand, theories are incommensurable if they are embedded in starkly contrasting conceptual frameworks whose languages do not overlap sufficiently to permit scientists to directly compare the theories or to cite empirical evidence favoring one theory over the other. Discussed by Ludwik Fleck in the 1930s, and popularized by Thomas Kuhn in the 1960s, the problem of incommensurability results in scientists talking past each other, as it were, while comparison of theories is muddled by confusions about terms, contexts and consequences.

Thesis

In 1962, Thomas Kuhn and Paul Feyerabend both independently introduced the idea of incommensurability to the philosophy of science. In both cases the concept came from mathematics and in its original sense is defined as the absence of a common unit of measurement that would allow a direct and exact measurement of two variables, such as the prediction of the diagonal of a square from the relationship of its sides.

Philosophy of science

Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ultimate purpose of science. This discipline overlaps with metaphysics, ontology, and epistemology, for example, when it explores the relationship between science and truth.

There is no consensus among philosophers about many of the central problems concerned with the philosophy of science, including whether science can reveal the truth about unobservable things and whether scientific reasoning can be justified at all. In addition to these general questions about science as a whole, philosophers of science consider problems that apply to particular sciences (such as biology or physics). Some philosophers of science also use contemporary results in science to reach conclusions about philosophy itself.

While philosophical thought pertaining to science dates back at least to the time of Aristotle, philosophy of science emerged as a distinct discipline only in the middle of the 20th century in the wake of the logical positivism movement, which aimed to formulate criteria for ensuring all philosophical statements' meaningfulness and objectively assessing them. Thomas Kuhn's landmark 1962 book The Structure of Scientific Revolutions was also formative, challenging the view of scientific progress as steady, cumulative acquisition of knowledge based on a fixed method of systematic experimentation and instead arguing that any progress is relative to a "paradigm," the set of questions, concepts, and practices that define a scientific discipline in a particular historial period.

Philosophy

Philosophy is the study of the general and fundamental nature of reality, existence, knowledge, values, reason, mind, and language. The Ancient Greek word φιλοσοφία (philosophia) was probably coined by Pythagoras and literally means "love of wisdom" or "friend of wisdom". Philosophy has been divided into many sub-fields. It has been divided chronologically (e.g., ancient and modern); by topic (the major topics being epistemology, logic, metaphysics, ethics, and aesthetics); and by style (e.g., analytic philosophy).

As a method, philosophy is often distinguished from other ways of addressing such problems by its questioning, critical, generally systematic approach and its reliance on rational argument. As a noun, the term "philosophy" can refer to any body of knowledge. Historically, these bodies of knowledge were commonly divided into natural philosophy, moral philosophy, and metaphysical philosophy. In casual speech, the term can refer to any of "the most basic beliefs, concepts, and attitudes of an individual or group," (e.g., "Dr. Smith's philosophy of parenting").

Science

Science is a systematic enterprise that creates, builds and organizes knowledge in the form of testable explanations and predictions about the universe.

Contemporary science is typically subdivided into the natural sciences which study the material world, the social sciences which study people and societies, and the formal sciences like mathematics. The formal sciences are often excluded as they do not depend on empirical observations. Disciplines which use science like engineering and medicine may also be considered to be applied sciences.

During the middle ages in the Middle East, foundations for the scientific method were laid by Alhazen. From classical antiquity through the 19th century, science as a type of knowledge was more closely linked to philosophy than it is now and, in fact, in the West the term "natural philosophy" encompassed fields of study that are today associated with science, such as physics, astronomy and medicine.

In the 17th and 18th centuries scientists increasingly sought to formulate knowledge in terms of laws of nature. Over the course of the 19th century, the word "science" became increasingly associated with the scientific method itself, as a disciplined way to study the natural world. It was in the 19th century that scientific disciplines such as physics, chemistry, and biology reached their modern shapes. The same time period also included the origin of the terms "scientist" and "scientific community," the founding of scientific institutions, and increasing significance of the interactions with society and other aspects of culture.