Rationality and Fallibilism

Dogmatic philosophers see rational thought or action as being that which conforms with the forces or the dictates of Reason. In contrast, I offer a critical account. First, after rejecting the theories of Aristotle, Bill Brewer, John Broome, Rene Descartes, and Christine Korsgaard, I explain deductive reasoning as guessing, testing and freely deciding. I expound Lewis Carroll’s puzzle about deduction before repudiating Gilbert Ryle’s celebrated solution. Second, I outline how philosophers’ attempts to understand knowledge typically founder on the problem of scepticism, before explaining Karl Popper’s revolutionary solution in terms of conjecture, criticism and methodological rules. Third, I discuss and reject solutions offered by contemporary decision theory to decision problems afflicted by risk, ignorance and uncertainty, and I offer solutions in terms of guessing and testing. I consider some well-known decision problems involving trapped miners and a doctor, and I expose the confusions of Niko Kolodny and John MacFarlane, of Peter Graham, and of Helen Steward. I discuss the matter of blame before considering how we can decide what to do when we cannot know what we ought to do. Finally, I contrast my Popper-inspired approach to practical and theoretical reasoning and rationality with traditional and contemporary ones.