Dr. Denis Walsh is an Academic Director and Professor at the University of Toronto's Institute for the History and Philosophy of Science and Technology. He is also currently co-PI on a collaborative project with evolutionary biologists entitled "Agency in Living Systems", and a member of the Leadership Team of the Schwartz Reisman Institute for Technology and Society at the University of Toronto.

Dr. Walsh has pioneered and defended the so-called 'statistical' interpretation of evolutionary population dynamics, according to which traditional Modern Synthesis models of evolution identify statistical parameters that predict and explain evolutionary population change but do not articulate the causes of population change. He develops the view that (perhaps uniquely) evolutionary theory deploys three distinct modes of explanation—causal, statistical, and teleological. Orthodox philosophical opinion, however, holds that the only genuine scientific explanations are causal. Walsh articulates a generalised account of scientific explanations in which causal, statistical, and teleological explanations are all legitimate variants (modes). He uses this conception of explanation to develop an account of the place of organisms, as natural purposive entities, in evolutionary processes. Organisms, in this view, are agents of evolutionary change, and not simply objects.

He received his PhD in Biology from McGill University. Subsequently, Dr. Walsh studied Philosophy at King's College Cambridge, and then on to King's College London, where he completed the MPhil and PhD (modal logic and modal metaphysics).