Timothy Williamson b. 1955

Timothy Williamson is a British philosopher, Wykeham Professor of Logic at the University of Oxford, and one of the most influential analytic philosophers of his generation. Knowledge and Its Limits defended the audacious thesis that knowledge is the most general factive mental state and cannot be analyzed in terms of more basic conditions such as belief, truth, and justification. The Philosophy of Philosophy offered a robust defense of the methods of analytic philosophy as continuous with the sciences, while his work on vagueness, modality, and counterfactuals has reshaped contemporary metaphysics and philosophical logic.

Timothy Williamson was born at Uppsala in Sweden in August 1955 to British parents and grew up in the United Kingdom. He read mathematics and philosophy at Balliol College, Oxford, took his bachelor's in 1976 and his doctorate at Oxford in 1981 under Michael Dummett and Dana Scott. He taught at Trinity College Dublin and at University College Oxford, was Wykeham Professor of Logic at Oxford from 2000 until 2024, and concurrently held visiting and permanent positions at Edinburgh, Princeton, and Yale.

His books include Identity and Discrimination (1990), Vagueness (1994), Knowledge and Its Limits (2000), The Philosophy of Philosophy (2007), Modal Logic as Metaphysics (2013), the popular dialogue Tetralogue (2015), Doing Philosophy: From Common Curiosity to Logical Reasoning (2018), and Suppose and Tell: The Semantics and Heuristics of Conditionals (2020).

Williamson has defended an epistemicist account of vagueness on which there are sharp but unknowable boundaries to vague predicates, a knowledge-first epistemology in which knowledge is the basic mental state and not a special kind of justified true belief, and a metaphysics that takes higher-order modal logic as a guide to ontology. His meta-philosophical writings have made him a leading defender of the rigour and continuity of analytic philosophy.