Philosopher who identified consciousness, sensation and thought with physical processes of the brain
Jack Smart, who has died aged 92, changed the course of philosophy of mind. He was a pioneer of physicalism – the set of theories that hold that consciousness, sensation and thought do not, as they seem to, float free of physicality, but can – or will eventually – be located in a scientific material worldview. His article Sensations and Brain Processes (1959) put forward his Type Identity theory of mind – that consciousness and sensations are nothing over and above brain processes. Invariably included in any collection of mind-body problem papers, it is now part of the canon, for, along with UT Place and David Armstrong, Smart converted what was once "the Australian heresy" into orthodoxy.
While all three were based principally at Australian universities, Place was born in Yorkshire and Smart to Scottish parents in Cambridge, where his father was professor of astronomy. Jack went to the Leys School in the city, studied maths, physics and philosophy at Glasgow University, and during the second world war served mainly in India and Burma. He gained a BPhil at Queen's College, Oxford, in 1948, under the behaviourist Gilbert Ryle, and in 1950 became professor at Adelaide, where he stayed until 1972.
Away from the language-centred philosophy of Britain, Smart was freer to draw the implications that science had for philosophy. He began to ask why consciousness alone should remain exempt from physico-chemical explanation. The behaviourist view he had espoused at Oxford got round this question by denying that mental states, like anger, pain or believing, can even qualify as things or events, whether physical or non-physical. Rather, to talk about mental states is, for behaviourism, simply to talk about collections of actual or potential behaviour. But Smart objected that in this case seeing an after-image due to strong light can amount to nothing more than saying "I have a yellowish-orange after-image". Such an utterance is surely superfluous to the sensation on which the utterer, who has just experienced it, would be "reporting".
Smart agreed with old-fashioned mind-body dualism – against behaviourism – that many mental states are indeed episodic, inner and potentially private; what he disputed was that this made their essential nature non-physical. "Why should not sensations just be brain processes of a certain sort?" he demanded. If regarded as neuro-physiological processes, they too would be potentially explicable by scientific laws.
It is no objection that someone reporting their sensations does not know or feel that they are brain processes. Because such reports are "topic-neutral" – uncommitted as to what sort of process, ghostly or material, is going on – they are open to revision by increasing scientific knowledge.
Smart's Type Identity theory unleash ed a torrent of argument that has persisted over the last half century. Characteristic of him in its no-nonsense seizing of the main issue, Sensations and Brain Processes ends on a note of satisfaction at a job well done, having presented eight objections to its thesis, and eight answers. As was soon pointed out, however, to postulate specific neuro/mental identities inadvertentlyrestricts mental states to human brains, ignoring the wide range of sensation processes in other species.
But Smart regarded the development of complementary ideas in the field with equanimity, in fact claimed that his "topic neutral" approach had anticipated the theory of functionalism whichthat soon became fashionable.
But Smart was blithe about the development of complementary theories. He claimed that his own "topic-neutral" approach had anticipated the soon-prevailing theory of functionalism, which identifies mental states, like software programs, by what they do rather than how they are physically implemented.
He was one of the leading figures to push Anglo-American analytic philosophy into collusion with the sciences. In his earliest article, The River of Time (1949), published while he was a junior research fellow at Corpus Christi College, Oxford, he invoked Einstein's special theory of relativity, arguing that our notion of time passing must be an illusion – a then-unfashionable position, which, largely thanks to him, moved more into the mainstream. He developed "the tenseless theory of time", influencing later philosophers of time such as DH Mellor and Huw Price. We should, he said, consider reality "a four-dimensional space, three of whose dimensions correspond to space in the ordinary sense of this word, and one of whose dimensions is taken to be a time dimension".
Over the years he changed his mind as to his explanation – respectively linguistic, then psychological – for why we feel as if time flows, but always remained an eternalist, claiming all points in time to be equally real. A few years ago, meeting an exponent of the opposite view, the presentist philosopher John Bigelow, at a conference, he remarked that he very much hoped that presentism is false, since, if not, this beloved friend would only be a single instantaneous time-slice: much better to regard him as an elongated and eternal space-time worm.
In Philosophy and Scientific Realism (1963) and subsequently, Smart acknowledged that what science tells us about the world is often hard to reconcile with how it seems in experience, but he stuck up for a reality that exists independently of our conceptions of it. He fiercely combated anti-realism, and postmodern notions that scientific theories (and the unobservable entities they depend on) are merely helpful, but arbitrary and disposable, human tools.
If the theories were not approximately true, and the entities did not more-or-less exist, went his No Miracles argument, the predictive success they have would be miraculous. One reason he gave for liking Australian philosophers was that they were not as liable to talk nonsense as French ones did.
After an Episcopalian upbringing – his brother, Ninian Smart, was a theology professor and respected writer on religion – Smart had become "a reluctant atheist". Whether in philosophy of mind, philosophy of science or ethics, he strove to resolve apparently mysterious entities or values as parts of the natural world. His aim throughout was to produce a comprehensive worldview that accommodated both common-sense and scientific stringency. In moral philosophy, he applied his swashbuckling approach to bringing utilitarianism – the theory that goodness consists of promoting the greatest overall happiness – back to centre stage after it had been ignored for more than 50 years.
In An Outline of a System of Utilitarian Ethics (1961; and published in tandem with Bernard Williams's A Critique of Utilitarianism in 1973), he embraced its then-unpopular extreme form – act utilitarianism. Its milder version, rule utilitarianism, was "superstitious rule worship", he said, and negated precisely the deft adaptability to the actual situation that was utilitarianism's whole point. He recognised the unpalatable upshot of his ethical arguments – that they would sanction an innocent man being killed if greater suffering were thereby spared – but nonetheless stuck to them.
The entry for "OutSMART" in the jocular Philosophers' Lexicon refers to Smart's readiness, rare in a philosopher, to embrace his opponents' reductio ad absurdum arguments – take-that-to-its-logical-conclusion rebuffs that are traditionally designed to make the rebuffed one revise his view. For all his geniality and exuberant laughter, he admitted that truth could be unsatisfactory.
In addition to his chair at the Australian National University, Canberra (1976-85), at various times Smart had visiting posts in the US at Princeton, Harvard, Yale and Stanford. He was also awarded honorary fellowships by his Oxford colleges.
An enthusiastic player of cricket and hockey, Smart won university colours in both. He would sometimes hold a small radio to his ear during philosophy seminars to check on the Test Match score. In others, he sometimes snoozed – or seemed to. Suddenly he would open his eyes and ask a devastating question. He loved bush-walking, but tended to get lost, and the friends he took with him were dismayed equally by his excellent stamina and poor sense of direction.
Smart was that rare phenomenon – a great and successful philosopher who had no enemies. Brisk and down-to-earth in debate, he was never aggressive. There are endless anecdotes of his spontaneous kindness. "We've got to find you a bike," was his first comment to a lonely visiting student, and the bike which duly turned up next day transformed his stay. Smart himself continued to cycle as an emeritus professor well into his 70s. The child-like, unpretentious openness for which he was so much loved was reflected in the fearless, direct clarity with which he did philosophy.With his first wife, Janet Paine, who died in 1967, he had two children, Helen and Robert. They survive him, as does his second wife, Elizabeth Warner, whom he married in 1968.
• Jack (John Jamieson Carswell) Smart, philosopher, born 16 September 1920; died 6 October 2012