1926 – 2014
David Malet Armstrong (1926–2014) was an Australian analytic philosopher and Emeritus Professor at the University of Sydney, widely regarded as one of the most significant metaphysicians of the twentieth century. He is best known for defending naturalism across multiple domains, developing an immanent realist theory of universals, and his influential contributions to philosophy of mind, laws of nature, and truthmaker theory.
Developed immanent realism about universals, arguing universals are instantiated in space-time rather than abstract realms
Defended a functionalist materialist theory of mind in A Materialist Theory of the Mind (1968)
Advanced a necessitarian account of laws of nature as relations between universals
Contributed foundational work to truthmaker theory, grounding truth in worldly states of affairs
Developed a combinatorial theory of possibility, constructing modality from actual particulars and universals