Willard Van Orman Quine, who died on December 25th aged 92, was regarded by many as the greatest American philosopher in the second half of the 20th century. He revolutionised developments in epistemology, metaphysics, logic, philosophy of language and philosophy of maths.
The youngest son of an engineer, he was born in Akron, Ohio, and attended Oberlin College, where he studied mathematics and philosophy. He won a scholarship to Harvard and completed his Ph.D in two years on Bertrand Russell and Alfred Whitehead's Principia Mathematica.
He travelled to Europe on a research fellowship in 1932 and met members of the Vienna Circle.odel, who had just completed his incompleteness theorem. The circle It espoused an anti-metaphysical and scientific-minded philosophy. Willard Quine's distinctive philosophical contribution was to develop its views in revolutionary ways, undermining positivism from within using resources from American pragmatism and creating a new philosophical landscape.
In 1951, his article Two Dogmas Of Empiricism caused a furore in the philosophical world. It challenged received notions of knowledge, meaning and truth, and exceeded even the extreme empiricism of logical positivism by arguing that logic and maths, like factual statements, are open to revision in the light of experience.
Experience, he added, does not confirm or falsify individual statements, but instead confronts an interlocking theory-laden system of statements, which has to be adjusted as a whole. And there cannot be any unique universally-held system of beliefs, he argued in his major work, Word And Object (1960), since the way any theory describes the world is relative to that theory's linguistic background.
Willard Quine revised and clarified such theses in more than 20 books and numerous articles. He taught at Harvard from 1936 - becoming a full professor in 1948 - until his retirement in 1978, and lectured all over the world.
When travelling, he preferred lecturing in the audience's language - German, Spanish, Portuguese or whatever - rather than English.
Despite the austerity of his philosophical vision (his taste for desert landscapes as he put it), he was a master stylist, revelling in the pithy epigram. In citing an historical forebear of his empiricist philosophy he
noted "The Human predicament is the human predicament". In holding that our account of what exists (our ontology) is best captured and expressed in the calculus of mathematical logic, he expressed it as, "to be is to be the value of a variable".
Among his most powerful metaphors was that of our system of beliefs as a web, with those parts at the centre less liable to change, those at the edge quite changeable - but every thing revisable in principle, even logic and mathematics.
His influence has been immense. Among the leading contemporary philosophers are his students Hilary Putnam and Donald Davidson, who respond in quite different ways to his work. Developments in cognitive science are indebted to his lead (especially the work of Daniel Dennett), while he has set much of the agenda for philosophy of language, epistemology and curiously enough contemporary metaphysics.
He resisted the therapeutic tendency of philosophers influenced by the later Ludwig Wittgenstein, robustly producing a systematic and distinctive metaphysical system. In so doing Willard Quine strongly influenced the contemporary practice of philosophy in America, Britain and elsewhere.
He was distinguished by his openness and generosity to students, acknowledging the "close collaboration" on Word and Object of Donald Davidson, then a Harvard classics student, later the renowned philosopher.
Willard Quine is often considered a behaviourist (someone who sees all mental life as nothing more than observable behaviour). Certainly he claimed that behaviourism is essential in linguistics, but he eventually adopted Davidson's anomalous monism, which holds that, although there is nothing over and above the physical, our mental states cannot neatly be identified with our brain states, or subsumed under physical laws.
As for the immemorial problem of how we can know about the world around us, his "naturalised epistemology" relocated the problem as that of how we learn to talk about things. If there is any dualistic split, it is not that between mind and body, but between physical objects, including humans, and the concepts that refer to them. This led to the charge that he devalues the mental. "I have been accused of denying consciousness," he said, "but I am not conscious of having done so." However, his 1985 autobiography, The Time Of My Life, is little more than a travel itinerary, notoriously lacking in personal input or glimpses of subjectivity. Some take this as conclusive evidence of a lack of sensibility on his part leading to a flawed view of mind. Yet even if true, it doesn't deny the strength of the arguments he deploys for his position, which is what makes him a philosopher of first rank.
Willard Van Orman Quine: born 1908; died, December, 2000.