Deductive reasoning, also called deductive logic, is reasoning which constructs or evaluates deductive arguments. Deductive arguments are attempts to show that a conclusion necessarily follows from a set of premises or hypotheses. A deductive argument is valid if the conclusion does follow necessarily from the premises, i.e., if the conclusion must be true provided that the premises are true. A deductive argument is sound if it is valid and its premises are true. Deductive arguments are valid or invalid, sound or unsound, but are never false nor true. Deductive reasoning is a method of gaining knowledge. An example of a deductive argument: #All men are mortal #Socrates is a man #Therefore, Socrates is mortal

The first premise states that all objects classified as "men" have the attribute "mortal". The second premise states that "Socrates" is classified as a man – a member of the set "men". The conclusion states that "Socrates" must be mortal because he inherits this attribute from his classification as a man.

Law of detachment

The law of detachment is the first form of deductive reasoning. A single conditional statement is made, and then a hypothesis (P) is stated. The conclusion (Q) is deduced from the hypothesis and the statement. The most basic form is listed below: #P→Q #P (Hypothesis stated) #Q (Conclusion given)

We can conclude Q from P by using the law of detachment from deductive reasoning. However, if the conclusion (Q) is given instead of the hypothesis (P) then there is no valid conclusion.

The following is an example of an argument using the law of detachment in the form of an If-then statement: #If m∠A>90°, then ∠A is an obtuse angle. #m∠A=120°. #∠A is an obtuse angle.

Since the measurement of angle A is greater than 90° degrees, we can deduce that A is an obtuse angle.

Law of syllogism

The law of syllogism takes two conditional statements and forms a conclusion by combining the hypothesis of one statement with the conclusion of another. The following is an example: #If Larry is sick, then he will be absent from school. #If Larry is absent, then he will miss his classwork. #If Larry is sick, then he will miss his classwork.

We deduced the solution by combining the hypothesis of the first problem with the conclusion of the second statement.

Deductive logic

Deductive arguments are generally evaluated in terms of their ''validity'' and ''soundness''.

An argument is ''valid'' if it is impossible for its premises to be true while its conclusion is false. In other words, the conclusion must be true if the premises, whatever they may be, are true. An argument can be valid even though the premises are false.

An argument is ''sound'' if it is valid and the premises are true.

The following is an example of an argument that is valid, but not sound; a premise is false: #Everyone who eats steak is a quarterback. #John eats steak. #Therefore, John is a quarterback.

The example's first premise is false (there are people who eat steak that are not quarterbacks), but the conclusion must be true, so long as the premises are true (i.e. it is impossible for the premises to be true and the conclusion false). Therefore the argument is ''valid'', but not ''sound''.

The theory of deductive reasoning known as categorical or term logic was developed by Aristotle, but was superseded by propositional (sentential) logic and predicate logic.

Deductive reasoning can be contrasted with inductive reasoning. In cases of inductive reasoning, even though the premises are true and the argument is "valid", it is possible for the conclusion to be false (determined to be false with a counterexample or other means).

Hume's skepticism

Philosopher David Hume presented grounds to doubt deduction by questioning induction. Hume's problem of induction starts by suggesting that the use of even the simplest forms of ''induction'' simply cannot be justified by inductive reasoning itself. Moreover, induction cannot be justified by deduction either. Therefore, induction cannot be justified rationally. Consequentially, if induction is not yet justified, then deduction seems to be left to rationally justify itself – an objectionable conclusion to Hume.

Hume did not provide a strictly rational solution per se. He simply explained that we do induce, and that it is useful that we do so, but not necessarily justified. Certainly we must appeal to first principles of some kind, including laws of thought.

See also

Argument (logic)

Logic

Mathematical logic

Abductive reasoning

Analogical reasoning

Correspondence theory of truth

Defeasible reasoning

Decision making

Decision theory

Fallacy

Geometry

Hypothetico-deductive method

Inquiry

Inductive reasoning

Inference

Logical consequence

Natural deduction

Propositional calculus

Retroductive reasoning

Scientific method

Soundness

Syllogism

References

Further reading

Vincent F. Hendricks, ''Thought 2 Talk: A Crash Course in Reflection and Expression'', New York: Automatic Press / VIP, 2005, ISBN 87-991013-7-8

Philip Johnson-Laird, Ruth M. J. Byrne, ''Deduction'', Psychology Press 1991, ISBN 9780863771491jiii

Zarefsky, David, ''Argumentation: The Study of Effective Reasoning Parts I and II'', The Teaching Company 2002

Category:Deduction Category:Problem solving Category:Reasoning

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Region	Western Philosophy
Era	21st-century philosophy
Color	#B0C4DE
Name	William Lane Craig
Birth date	August 23, 1949
Birth place	Peoria, Illinois
School tradition	Analytic Philosophy
Main interests	Philosophy of religion, Natural theology, Philosophy of time, Christian Apologetics
Notable ideas	Kalam cosmological argument
Influences	Alvin Plantinga, Francis Schaeffer, Edward John Carnell, Stuart Hackett, John Hick, Wolfhart Pannenberg
Influenced	J. P. Moreland, Francis Beckwith }}

William Lane Craig (born August 23, 1949) is an American Evangelical Christian apologist in the evidentialist tradition. Craig is a prolific debater, philosophical theologian, and analytic philosopher known for his work on the existence of God, defense of Christian theism, philosophy of religion, historicity of Jesus and the philosophy of time. In 1979, he authored ''The Kalam Cosmological Argument'', a defense of the argument of the same name. He is currently a Research Professor of Philosophy at Talbot School of Theology, Biola University.

Biography

Craig received a BA in Communications from Wheaton College, Illinois in 1971 and two MA degrees from Trinity Evangelical Divinity School, Deerfield, Illinois, in 1975, in philosophy of religion and church history. He earned a Ph.D. in Philosophy at the University of Birmingham, England in 1977 and Th.D. under Wolfhart Pannenberg at the University of Munich in 1984.

From 1980 to 1986 he was an Assistant Professor of Philosophy at Trinity Evangelical Divinity School. He briefly held the position of associate professor of Religious Studies at Westmont College, Santa Barbara, California in 1986-1987. Between 1987 and 1994 Craig pursued further research at the University of Leuven, Belgium. Since 1996 he has been a Research Professor of Philosophy at Talbot School of Theology, La Mirada, California.

Career

He is a fellow of the Discovery Institute's Center for Science and Culture, which is the hub of the intelligent design movement, and a fellow of the International Society for Complexity, Information and Design(ISCID).

Craig is a Molinist who embraces a Reformed epistemology and in regard to biological origins is inclined towards progressive creationism, although he concedes the possibility of theistic evolution. He has published on the historicity of the resurrection accounts of Jesus and the philosophy of time for which he advocates a tensed or A-theory of time and a Neo-Lorentzian interpretation of the theory of relativity. He argues for a finely tuned theistic universe, a personal cause of the universe and a theistic objective morality. His work in Christian apologetics includes advocacy of intelligent design, and critiques of "New Atheism," liberal theology, metaphysical naturalism, logical positivism and scientism, postmodernism, anti-realism, moral relativism and subjectivism, Mormonism, Islam, and the methodology and conclusions of the Jesus Seminar.

Bibliography

''The Kalam Cosmological Argument''. London: MacMillan. 1979. ISBN 157910438X / ISBN 978-1579104382

''The Cosmological Argument from Plato to Leibniz''. London: MacMillan. 1980. ISBN 1579107877 / ISBN 978-1579107871

''The Son Rises: Historical evidence for the resurrection of Jesus''. Chicago: Moody Press. 1981. ISBN 9781579104641 / ISBN 978-1579104641

''Apologetics: An Introduction''. Chicago: Moody Press. 1984. ISBN 0802404057

''The Historical Argument for the Resurrection of Jesus during the Deist Controversy''. Toronto: Edwin Mellen. 1985. ISBN 0-88946-811-7

''The Only Wise God: The Compatibility of Divine Foreknowledge and Human Freedom''. Grand Rapids: Baker Bookhouse. 1987. ISBN 1579103162 / ISBN 978-1579103163

''The Problem of Divine Foreknowledge and Future Contingents from Aristotle to Suarez''. Leiden: E.J. Brill. 1988. ISBN 9004085165 / ISBN 978-9004085169

''Knowing the Truth About the Resurrection''. Ann Arbor: Servant. 1988. ISBN 089283384X / ISBN 978-0892833849

''Assessing the New Testament Evidence for the Historicity of the Resurrection of Jesus''. Toronto: Edwin Mellen Press. 1989. ISBN 0889466165/ ISBN 978-0889466166

''Divine Foreknowledge and Human Freedom: The Coherence of Theism I: Omniscience''. Leiden: E.J. Brill. 1990. ISBN 9004092501 / ISBN 978-9004092501

''No Easy Answers''. Chicago: Moody Press. 1990. ISBN 0802422837 / ISBN 978-0802422835

''Theism, Atheism, and Big Bang Cosmology'' (with Quentin Smith). Oxford: Clarendon Press. 1993. ISBN 978-0198263838

''The Tensed Theory of Time: A Critical Examination''. Dordrecht: Kluwer Academic Publishers. ISBN 0792366344 / ISBN 978-0792366348

''Will the Real Jesus Please Stand Up? A Debate Between William Lane Craig and John Dominic Crossan''. Grand Rapids: Baker Bookhouse. 1998.

''God, Are You There?''. Atlanta: RZIM. 1999. ISBN 1930107005 / ISBN 978-1930107007

''The Tenseless Theory of Time: A Critical Examination''. Dordrecht: Kluwer Academic Publishers. 2000. ISBN 9780792366355 / ISBN 978-0792366355

''God, Time and Eternity''. Dordrecht: Kluwer Academic Publishers. 2001. ISBN 9781581342413 / ISBN 978-1581342413

''Time and The Metaphysics of Relativity''. Dordrecht: Kluwer Academic Publishers. 2001. ISBN 0 7923 6668 9

''Time and Eternity: Exploring God's Relationship to Time''. Wheaton: Crossway. 2001. ISBN 9781581342413 / ISBN 978-1581342413

''What Does God Know?'' Atlanta: RZIM. 2002. ISBN 9781930107052

''Hard Questions, Real Answers''. Wheaton: Crossway Books. 2003. ISBN 9781581344875 / ISBN 978-1581344875

''God?: A Debate Between a Christian and an Atheist''(with Walter Sinnot-Armstrong). New York: Oxford University Press. 2003.

''Philosophical Foundations for a Christian Worldview'' (with J.P. Moreland). Downers Grove: InterVarsity Press. 2003.

''Creation out of Nothing: Its Biblical, Philosophical, and Scientific Exploration'' (with Paul Copan). Grand Rapids: Baker Bookhouse. 2004. ISBN 0801027330

''Reasonable Faith''. Wheaton: Crossway. 1994. rev. 3rd ed. 2008. ISBN 0891077642 / ISBN 978-0891077640

''On Guard: Defending Your Faith with Reason and Precision''. Colorado Springs: David C. Cook. 2010. ISBN 1434764885 / ISBN 978-1434764881

See also

List of American philosophers

References

External links

Faculty webpage

Comprehensive Debate list

Interviews from the program Closer to Truth

Category:1949 births Category:Living people Category:Alumni of the University of Birmingham Category:Ludwig Maximilian University of Munich alumni Category:American philosophers Category:American religion academics Category:American theologians Category:Analytic philosophers Category:Biblical scholars Category:Biola University faculty Category:Intelligent design advocates Category:Christian philosophers Category:Christian apologists Category:Christian writers Category:Christian scholars Category:Discovery Institute fellows and advisors Category:Fellows of the International Society for Complexity, Information, and Design Category:Philosophers of religion Category:People from Keokuk, Iowa Category:American Christians Category:Trinity Evangelical Divinity School alumni Category:Wheaton College (Illinois) alumni

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William Lane (6 September 1861 – 26 August 1917) was a journalist, advocate of Australian labour politics and a utopian.

Early life

Lane was born in Bristol, England, eldest son of James Lane, a Protestant Irishman and landscape gardener, and his English wife Caroline, ''née'' Hall. When Lane was born his father was earning a miserable wage, but later his circumstances improved and he became an employer. The boy was educated at Bristol Grammar School and showed ability, but he was sent early to work as an office boy. Lane's mother died when he was 14 years of age, and at age 16 he migrated to Canada, then to the United States, where he worked first as a printer, then as a reporter for the Detroit Free Press (1881), there meeting his future wife Ann MacGuire. In 1885 they migrated to Brisbane, Australia, where Lane immediately got work as a feature writer for the weekly newspaper ''Queensland Figaro'', then as a columnist for the newspapers Brisbane Courier and Evening Telegraph, using a number of pseudonyms ("Lucinda Sharpe", which some consider to be the work of Annie Lane, "John Miller" and "Sketcher").

A life-long abstainer from alcohol, in 1886 he created an Australia-wide sensation by spending a night in the Brisbane lock-up disguised as a drunk, and subsequently reporting the conditions of the cells as "Henry Harris". Lane's father was a drunk who impoverished the family.

With the growth of the Australian labour movement, "Sketcher"'s columns, especially his "Labour Notes" in the ''Evening Telegraph'', increasingly promoted labourist philosophy, and Lane himself attended meetings supporting all manner of popular causes, speaking with his "American twang" against repressive laws and practices and Chinese immigrants.

After becoming the de facto editor of the Courier, Lane departed during November 1887 to found the weekly ''The Boomerang'', "a live newspaper, racy, of the soil", in which pro-worker themes and lurid racism were brought to a fever-pitch by both "Sketcher" and "Lucinda Sharpe". He became a powerful supporter of Emma Miller and Women's suffrage. A strong proponent of Henry George's Single Tax Movement, Lane became increasingly committed to a radically alternative society, and ended his relationship with the ''Boomerang'' due to its private ownership.

In May 1890 he began the community-funded Brisbane weekly ''The Worker'', the rhetoric of which became increasingly threatening towards the employers, the government, and the British Empire itself. The defeat of the 1891 Australian shearers' strike convinced Lane that there would be no real social change without a completely new society, and ''The Worker'' became increasingly devoted to his New Australia utopian idea.

''The Workingman's Paradise'', an allegorical novel written in sympathy with the shearers involved in the 1891 Shearer's Strike, was published under his pseudonym ''John Miller'' in early 1892. In the novel Lane articulated the belief that anarchism is the noblest social philosophy of all. Through the novel's philosopher and main protagonist he relates his belief that society may have to experience a period of State socialism to achieve the ideal of Communist anarchism. Mary Gilmore, later a celebrated Australian writer, said in one of her letters ''"the whole book is true and of historical value as Lane transcribed our conversations as well as those of others"''.

New Australia Colony

Contriving a division among Australian labour activists between the permanently disaffected and those who later formed the Australian Labor Party, Lane refused the Queensland Government's offer of a grant of land on which to create a utopian settlement, and began an Australia-wide campaign for the creation of a new society elsewhere on the globe, peopled by rugged and sober Australian bushmen and their proud wives.

Eventually Paraguay was decided upon, and Lane and his family and several hundred acolytes from New South Wales, Queensland and South Australia departed Mort Bay in Sydney in the ship ''Royal Tar'' on 1 July 1893.

New Australia soon had its crisis, brought on by the issues of inter-racial relationships (Lane singled out the Guarani as racially taboo) and alcohol. Lane's dictatorial manner soon alienated many in the community, and by the time the second boat-load of utopians arrived from Adelaide a year later, Lane had left with a core of devotees to form a new colony nearby named Cosme.

Eventually Lane became disillusioned with the process, and returned to Australia in 1899.

Later life

Lane then went with his family to New Zealand. After initial melancholia, he soon refound his old verve as a pseudonymous feature-writer from 1900 for the newspaper ''New Zealand Herald'' ("Tohunga"), only this time as ultra-conservative and pro-Empire. He had strong racial antipathy toward East Asians, and during World War I he developed extreme anti-German sentiments. He died on 26 August 1917 in Auckland, New Zealand, having been editor of the ''Herald'' from 1913 to 1917, much admired, having lost one son Charles at a cricket match in Cosme in Paraguay, and another Donald on the first day of the ANZAC landings (25 April 1915) on the beaches of Gallipoli.

References

Gavin Souter's account of Lane and New Australia in his ''A Peculiar People''

Peter Bruce's thesis (Univ Sydney) ''The Journalistic Career of William Lane''.

''Larry Petrie (1859-1901) - Australian Revolutionist?'' by Bob James

Whitehead, Anne (1997) ''Paradise Mislaid — in Search of the Australian Tribe of Paraguay'' University of Queensland Press, St. Lucia

External links

''Workingman's Paradise'', Pdf at University of Sydney

Category:1861 births Category:1917 deaths Category:Australian anarchists Category:Australian trade unionists Category:Australian journalists Category:New Zealand journalists Category:Old Bristolians Category:People from Bristol Category:Georgists

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