David Malet Armstrong

David Malet Armstrong (1926-2014) was an Australian philosopher best known for his work in metaphysics and the philosophy of mind. He is associated with a factualist ontology, a functionalist theory of mind, an externalist epistemology and a necessitarian view of the laws of nature. Educated in Sydney, Oxford and Melbourne, he taught at Melbourne before becoming Challis Professor of Philosophy at the University of Sydney, a post he held from 1964 until his retirement in 1991. He was also a visiting lecturer at several American institutions, including Yale and Stanford.

His philosophy is broadly naturalistic. It rests on the assumption that what exists is the physical world of space and time, and it rejects abstract objects, including Platonic forms. He held that universals exist, but only those that scientific investigation treats as basic, so that the full ontology of universals would be settled only when physics is complete. His central notion is the state of affairs, the instantiation of a particular by a universal, which he regarded as a fundamental structure of reality and not a mere sum of its parts. Building on this, he understood laws of nature as relations between universals, a non-Humean account he proposed alongside Michael Tooley and Fred Dretske.

His influence extends across contemporary analytic metaphysics, especially in debates about properties, relations and natural laws.