William James Fellow Award Address
"How We Reason"
A long-standing tradition is that we are rational because our thinking is founded on the ‘laws of thought.’ This talk argues to the contrary that we do not follow these laws, but depend on envisaging possibilities. We judge a conclusion to be valid if it holds in all such mental models of the given information, and probable if it holds in most of them. This theory is based on three principles: Each model represents a possibility, the structure of models corresponds with the structure of what they represent, and models normally represent only what is true. The talk describes evidence corroborating the theory. Inferences from one model are easier than those from multiple models. Knowledge affects the process of reasoning. When falsity matters to an inference, we commit systematic fallacies. Yet, we do grasp the force of counterexamples. We are not always rational, but we are not intrinsically irrational, either.
Introduction by Susan T. Fiske
23rd APS Annual Convention
Washington, D.C. -- 2011