Flew was born in London in 1923, the son of a Methodist minister. He was educated at St. Faith's Preparatory School, Cambridge followed by Kingswood School, Bath. During the Second World War he studied Japanese at the School of Oriental and African Studies, and was a Royal Air Force intelligence officer. After the war, Flew achieved a first class degree in Literae Humaniores at St John's College, Oxford.

Flew was a graduate student of Gilbert Ryle, and one of the more prominent in the group identified with ordinary language philosophy. He was among many Oxford philosophers fiercely criticised in Ernest Gellner's book Words and Things, which he called a "juvenile work". Another early highlight in his career was a 1954 debate with Michael Dummett over backward causation.

He was a Lecturer in Philosophy at Christ Church, Oxford from 1949 to 1950, and followed this with four years as a lecturer at the University of Aberdeen, and twenty years as Professor of Philosophy at the University of Keele. Between 1973 and 1983 he was Professor of Philosophy at the University of Reading, and on his retirement took up a half-time post for a few years at York University, Toronto.

In his 1975 book Thinking about Thinking, he developed the No true Scotsman fallacy.

Political commitments
Flew has a long history of involvement in conservative politics. In the late 1980s he became an active vice-president of the Western Goals Institute, a pressure group opposed to immigration and free trade, and supportive of apartheid. Flew was also a committee member of Majority Rights, alongside Ray Honeyford and Tim Janman, MP.

He sits on the management committee of The Freedom Association, and has contributed to Right Now! magazine, the Salisbury Review, and publications of the Libertarian Alliance, the Social Affairs Unit, the Society for Individual Freedom and the Institute of Economic Affairs.

Atheism and Deism
While an undergraduate, Flew attended the weekly meetings of C. S. Lewis's Socratic Club fairly regularly. Although he found Lewis to be "an eminently reasonable man" and "by far the most powerful of Christian apologists for the sixty or more years following his founding of that club," he was not persuaded by Lewis's argument from morality as found in Mere Christianity. Other philosophical proofs for God's existence also fail, according to Flew. The ontological argument in particular is false because it is based on the premise that the concept of Being can be derived from the concept of Goodness. Only the scientific forms of the teleological argument impress Flew as being decisive.

In God and Philosophy (1966) and The Presumption of Atheism (1984), Flew earned his fame by arguing that one should presuppose atheism until evidence of a God surfaces. He still stands behind this evidentialist approach, though he has been persuaded in recent years that such evidence in fact exists, and his current position appears to be deism. In a December 2004 interview, he said: I'm thinking of a God very different from the God of the Christian and far and away from the God of Islam, because both are depicted as omnipotent Oriental despots, cosmic Saddam Husseins.

On several occasions, apparently starting in 2001, rumours circulated claiming that Flew had converted from atheism. Flew refuted these rumours on the Secular Web website. In 2003, he signed the Humanist Manifesto III.

In December 2004, an interview with Flew conducted by Flew's friend and philosophical adversary Gary Habermas was published in Biola University's Philosophia Christi, with the title Atheist Becomes Theist - Exclusive Interview with Former Atheist Antony Flew. Flew agreed to this title. According to the introduction, Flew informed Habermas in January 2004 that he had become a deist, and the interview took place shortly thereafter. Then the text was amended by both participants over the following months prior to publication.

In the article Flew states that he has left his long-standing espousal of atheism by endorsing a deism of the sort that Thomas Jefferson advocated ("While reason, mainly in the form of arguments to design, assures us that there is a God, there is no room either for any supernatural revelation of that God or for any transactions between that God and individual human beings."). Flew states that certain philosophical and scientific considerations had caused him to rethink his lifelong support of atheism. However, it is clear from the interview that Flew is not comfortable with either Christianity or Islam.

Flew's conception of God as explained in the interview is limited to the idea of God as a first cause, and he rejects the ideas of an afterlife, of God as the source of good (he explicitly states that God has created "a lot of" evil), and of the resurrection of Jesus as an historical fact. He is particularly hostile to Islam, and says it is "best described in a Marxian way as the uniting and justifying ideology of Arab imperialism."

Flew has subsequently made contradictory statements to those given in the Habermas interview as justification for his endorsing of deism. In October 2004 (before the December publication of the Flew-Habermas interview), a letter written to Richard Carrier of the Secular Web, stated that he was a deist and also said that "I think we need here a fundamental distinction between the God of Aristotle or Spinoza and the Gods of the Christian and the Islamic Revelations. Flew also said: My one and only piece of relevant evidence [for an Aristotelian God] is the apparent impossibility of providing a naturalistic theory of the origin from DNA of the first reproducing species ... [In fact] the only reason which I have for beginning to think of believing in a First Cause god is the impossibility of providing a naturalistic account of the origin of the first reproducing organisms.

In an another letter to Carrier of 29 December 2004 Flew went on to retract his statement "a deity or a 'super-intelligence' [is] the only good explanation for the origin of life and the complexity of nature." "I now realize that I have made a fool of myself by believing that there were no presentable theories of the development of inanimate matter up to the first living creature capable of reproduction." wrote Flew.

He blames his error on being "misled" by Richard Dawkins, claiming Dawkins "has never been reported as referring to any promising work on the production of a theory of the development of living matter". (Dawkins has - in "Evolutionary Chemistry: Life in a Test Tube," published in the 21 May 1992 issue of Nature, with Laurence Hurst.) The work of physicist Gerald Schroeder had been influential in Flew's new belief, but Flew admitted to Carrier that he had not read any of the scientific critiques of Schroeder that Carrier referred him to.

When asked in December 2004 by Duncan Crary of Humanist Network News if he still stood by the argument presented in The Presumption of Atheism, Flew replied he did but he also restated his position as deist: "I'm quite happy to believe in an inoffensive inactive god". When asked by Crary whether or not he has kept up with the most recent science and theology, he responded with "Certainly not", stating that there is simply too much to keep up with. Flew also denied that there was any truth to the rumours of 2001 and 2003 that he had abandoned his atheism or converted to Christianity.

A letter on Darwinism and Theology which Flew published in the August/September 2004 issue of Philosophy Now magazine left the world hanging when it closed with, "Anyone who should happen to want to know what I myself now believe will have to wait until the publication, promised for early 2005, by Prometheus of Amherst, NY of the final edition of my God and Philosophy with a new introduction of it as ‘an historical relic’

But in 2005, when God and Philosophy was republished by Prometheus Books, the new introduction failed to conclusively answer the question of Flew's beliefs. The preface says the publisher and Flew went through a total of four versions (each extensively peer-reviewed) before coming up with one that satisfied them both. The result is an introduction, written in a distinctly detached third-person context, which raises ten matters that came about since the original 1966 edition. Flew refrains from personally commenting on these issues, and basically says that any book to follow God and Philosophy will have to take into account these ideas when considering the philosophical case for the existence of God.

1. A novel definition of "God" by Richard Swinburne.
2. The case for the existence of the Christian God by Swinburne in the book Is There a God?.
3. The Church of England's change in doctrine on the eternal punishment of Hell.
4. The question of whether there was only one big bang and if time began with it.
5. The question of multiple universes.
6. The fine-tuning argument.
7. The question of whether there is a naturalistic account for the development of living matter from non-living matter.
8. The question of whether there is a naturalistic account for non-reproducing living matter developing into a living creature capable of reproduction.
9. The concept of an Intelligent Orderer as explained in the book The Wonder of the World: A Journey from Modern Science to the Mind of God by Roy Abraham Varghese.
10. An extension of an Aristotelian/Deist concept of God that can be reached through natural theology, which was developed by David Conway.
11. In an interview with Joan Bakewell for BBC Radio 4 in March 2005, Flew rejected the fine-tuning argument, and retracted his earlier claims that the origins of DNA could not be explained by naturalistic theories. However, he restated his deism, with the usual provisos that his God is not the God of any of the revealed religions:

Q And certainly in America where you've been to lecture...
A Oh America, this is a very real phenomenon - oh yes. Part of Bush's second election success is due to this. And the unbelievers are absolutely furious, not believing that anyone with any intelligence could be anything but a Democratic voter.
Q What view do you take of what is happening in America - where presumably you're being hailed now as ... one of them?
A Well, too bad (laughs). I'm not 'one of them'.

Works
1. A New Approach to Psychical Research (1953)
2. New Essays in Philosophical Theology (1955) editor with Alasdair Macintyre
3. Essays in Conceptual Analysis (1956)
4. Hume's Philosophy of Belief (1961)
5. Logic And Language (1961) editor
6. God and Philosophy (1966)
7. Logic & Language (Second Series) (1966) editor
8. Evolutionary Ethics (1967)
9. An Introduction to Western Philosophy - Ideas and Argument from Plato to Sartre (1971)
10. Body, Mind and Death (1973)
11. Crime or Disease (1973)
12. Thinking About Thinking (1975)
13. Sociology, Equality and Education: Philosohical Essays In Defence Of A Variety Of Differences (1976)
14. Thinking Straight (1977)
15. A Dictionary of Philosophy (1979) editor, later edition with Stephen Priest
16. Philosophy, an Introduction (1979)
17. Libertarians versus Egalitarians (c.1980) pamphlet
18. The Politics of Procrustes: contradictions of enforced equality (1981)
19. Darwinian Evolution (1984)
20. The Presumption of Atheism (1984)
21. Examination not Attempted in Right Ahead, newspaper of the Conservative Monday Club, Conservative Party Conference edition, October 1985.
22. God: A Critical Inquiry (1986) - reprint of God and Philosophy (1966) with new introduction
23. Agency and Necessity (Great Debates in Philosophy) (1987) with Godfrey Norman Agmondis Vesey
24. Did Jesus Rise From the Dead? The Resurrection Debate (1987) with Gary Habermas
25. Power to the Parents: Reversing Educational Decline (1987)
26. Prophesy or Philosophy? Historicism or History? in Marx Refuted, edited by Ronald Duncan and Colin Wilson, Bath, (U.K.), 1987, ISBN 0-906798-71-X
27. Readings in the Philosophical Problems of Parapsychology (1987) editor
28. God, A Critical Inquiry (1988)
29. Does God Exist?: A Believer and an Atheist Debate (1991) with Terry L. Miethe
30. A Future for Anti-Racism? (Social Affairs Unit 1992) pamphlet
31. Atheistic Humanism (1993)
32. Thinking About Social Thinking (1995)
33. Education for Citizenship (Studies in Education No. 10) (Institute of Economic Affairs, 2000)
34. Merely Mortal? (2000)
35. Does God Exist: The Craig-Flew Debate (2003) with William Lane Craig
36. Social Life and Moral Judgment (2003)
37. God and Philosophy (2005) - another reprint of God and Philosophy (1966) with another new introduction

Quotations

"You cannot ... transmute some incoherent mixture of words into sense merely by introducing the three-letter word "God" to be its grammatical subject. "

"If it is to be established that there is a God, then we have to have good grounds for believing that this is indeed so. Until and unless some such grounds are produced we have literally no reason at all for believing; and in that situation the only reasonable posture must be that of either the negative atheist or the agnostic. So the onus of proof has to rest on the proposition [of theism]. "

"Pascal makes no attempt in this most famous argument to show that his Roman Catholicism is true or probably true. The reasons which he suggests for making the recommended bet on his particular faith are reasons in the sense of motives rather than reasons in [the] sense of grounds. Conceding, if only for the sake of the present argument, that we can have no knowledge here, Pascal tries to justify as prudent a policy of systematic self-persuasion, rather than to provide grounds for thinking that the beliefs recommended are actually true. "

"In the ordinary, everyday understandings of the words involved, to say that someone survived death is to contradict yourself; while to assert that all of us live forever is to assert a manifest falsehood, the flat contrary of a universally known truth: namely, the truth that all human beings are mortal. For when, after some disaster, the 'dead' and the 'survivors' have both been listed, what logical space remains for a third category? "

"However far back we may be able to trace the -- so to speak -- internal history of the Universe, there can be no question of arguing that this or that external origin is either probable or improbable. We do not have, and we necessarily could not have, experience of other Universes to tell us that Universes, or Universes with these particular features, are the work of Gods, or of Gods of this or that particular sort. "

"Now, if anything at all can be known to be wrong, it seems to me to be unshakably certain that it would be wrong to make any sentient being suffer eternally for any offence whatever. "

"What would have to occur or to have occurred to constitute for you a disproof of the love of, or of the existence of, God? "

"Someone tells us that God loves us as a father loves his children. We are reassured. But then something awful happens. Some qualification is made.... We are reassured again. But then perhaps we ask: what is this assurance of God's (appropriately qualified) love worth, what is this apparent guarantee really a guarantee against? Just what would have to happen not merely (morally and wrongly) to tempt but also (logically and rightly) to entitle us to say "God does not love us" or even "God does not exist"? "

"Once upon a time two explorers came upon a clearing in the jungle. In the clearing were growing many flowers and many weeds. One explorer says, "Some gardener must tend this plot." The other disagrees, "There is no gardener." So, they pitch their tents and set a watch. No gardener.... So they set up a barbed wire fence. They electrify it. They patrol it with bloodhounds.... But no shrieks even suggest that some intruder has received a shock. No movements of the wire ever betray an invisible climber. The bloodhounds never give cry. Yet still the Believer is not convinced. "But there is a gardener, invisible, intangible, insensible to electric shocks, a gardener who has no scent and makes no sound, a gardener who comes secretly to look after the garden which he loves." At last the Skeptic despairs, "But what remains of your original assertion? Just how does what you call an invisible, intangible, eternally elusive gardener differ from an imaginary gardener or even no gardener at all?" "

"The word "atheism", however, has in this contention to be construed unusually. Whereas nowadays the usual meaning of "atheist" in English is "someone who asserts that there is no such being as God", I want the word to be understood not positively but negatively. I want the originally Greek prefix "a" to be read in the same way in "atheist" as it customarily is read in such other Greco-English words as "amoral", "atypical", and "asymmetrical". In this interpretation an atheist becomes: not someone who positively asserts the non-existence of God; but someone who is simply not a theist. Let us, for future ready reference, introduce the labels "positive atheist" for the former and "negative atheist" for the latter."