Hilary Putnam (1926– ) is an American philosopher, best known for his work in epistemology, philosophy of language and philosophy of science.
Putnam offers a well-known thought experiment on the issue of scepticism: the brain in a vat. In it, he supposes that a brain in a vat, which is fed sensory data identical to that it would normally receive, has now way of knowing whether it is a brain in a vat or a brain in a skull. Essentially, the problem highlights the epistemic problem of confirming the existence of an external world.
Name: Hilary Whitehall Putnam
Born: July 31, 1926
Degrees: Ph.D. (UCLA, 1951)
BA (University of Pennsylvania)