Armstrong, David M. (1926–)

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ARMSTRONG, DAVID M.
(1926–)

David Malet Armstrong was born in Melbourne, Australia. He received his first degree at the University of Sydney where John Anderson held the Challis chair of philosophy. He then completed the bachelor of philosophy at Oxford (in 1954), being one of the first of the many Australian philosophers in the 1950s and 1960s to take that degree. After a short spell at Birkbeck College, London, he accepted a position at the University of Melbourne. In 1964 he took up the Challis chair in Sydney where he stayed until his retirement in 1991.

Armstrong has made influential contributions to a remarkable range of major topics in epistemology and metaphysics, including perception, materialism, bodily sensations, belief and knowledge, laws, universals, and the metaphysics of possibility. Recurrent themes have been the need to reconcile what the philosopher says with the teachings of science, a preference for realist over instrumentalist theories, and an interest in the fundamental elements of being. A feature of his work is his ability to write about difficult issues with directness and clarity without sacrificing rigor.

Armstrong's A Materialist Theory of the Mind (1968) is a seminal and comprehensive presentation of the mind-brain identity theory, the view that mental states are states of the brain. Armstrong argues that for each mental state, there is a distinctive functional role. For each mental state, we can specify what it does by way of mediating between inputs, outputs, and other mental states. For example, pain is typically caused by bodily injury and typically causes behavior that tends to alleviate it; thirst is typically caused by lack of water and typically gives rise to behavior that leads to drinking water, provided there is water knowingly available to the subject. This means, Armstrong argues, that the question of the identity of a given mental state is nothing more than the question of the identity of that which plays the functional role distinctive of that state: Thirst is that which plays the role just described. It is then a question for science what state in fact plays that role, and that it will in fact be some state of the brain. Thus, Armstrong derives the mind-brain identity theory from a view about the distinctive roles played by mental states, combined with a view about what kinds of states—namely brain states—play those roles.

In the philosophy of perception he was one of the first to argue that we must move away from the tradition that thinks of perception as acquaintance with a special, mental item sometimes called a "sense datum." Instead, we should adopt an account that analyses perception as the acquisition of putative belief about our world—an account that has the signal advantage of making sense of the role of perception in our traffic with the world. Armstrong saw bodily sensations as being a special kind of perception—in the case of pain, a perception of putative damage in a part of one's body, accompanied by a desire that it cease. His work on sensations and perception may be seen as a precursor to currently much discussed representationalist accounts that analyze an experience in terms of how the experience represents things as being.

Armstrong revived interest in F. P. Ramsey's view that belief is like a map by which we steer, in opposition to approaches that think of belief as a kind of "saying to oneself." His account of knowledge is a version of reliabilism: S's true belief that P is knowledge if it is an empirically reliable sign that P.

Armstrong is a realist about universals: they exist, they are not reducible to sets of particulars (squareness is not the set of square things), and although they serve as the truth makers for predication, there is no simple one-to-one correspondence between predicates and universals. But there are no uninstantiated universals, so Armstrong is not a realist in Plato's sense. Armstrong deploys his realism about universals to deliver an account of laws of nature and of possibility. Laws are to be understood in terms of relations of nomic necessitation between universals: Roughly "Every F is G" is a fundamental law if being F necessitates being G. Armstrong's account of possibility is a combinatorial one. The various possibilities are the various combinations and recombinations of particulars (individuals) and universals that obey the right combinatorial rules (for example, combining being square with not being square does not deliver a possibility).

Armstrong's overall position in analytic ontology—that part of metaphysics that seeks to inventory at the most fundamental level what there is—is given in A World of States of Affairs (1997), where states of affairs are the basis on which accounts of properties, relations, numbers, necessity, dispositions, classes, causes, and laws are constructed.