Timothy Williamson is Wykeham Professor of Logic at the University of Oxford and Whitney Griswold Visiting Professor at Yale University. He has also taught at MIT, Princeton, Edinburgh, Trinity College Dublin, Chinese University of Hong Kong, and elsewhere. He works on logic, philosophy of language, epistemology, metaphysics, and metaphilosophy. His books include Doing Philosophy, Tetralogue, Modal Logic as Metaphysics, and The Philosophy of Philosophy. He is a Fellow of the British Academy, Foreign Honorary Member of the American Academy of Arts and Sciences, and Member of the Academia Europaea.