The aim of this paper is to describe a methodology for revising logical principles in the light of empirical psychological findings. Historical philosophy of science and wide reflective equilibrium in ethics are considered as providing possible models for arguing from the descriptive to the normative. Neither is adequate for the psychology/logic case, and a new model is constructed, employing criteria for evaluating inferential systems. Once we have such criteria, the notion of reflective equilibrium becomes redundant.

The principle of charity says that all agents are rational. The principle of meta‐charity says that all agents believe all agents are rational. My thesis is that the arguments which are used to support charity also support meta‐charity. Meta‐charity implies meta‐meta‐charity. By recursion, the principle of charity implies that it is common knowledge. But there appears to be intelligent, well‐informed disagreement with the principle of charity. So if the entailment thesis holds, opponents of the principle of charity have a new (...) objection to the principle. Defenders of the principle of charity must either refute the entailment thesis or accept much stronger consequences than they expected.“As I am, so I see.”—Ralph Waldo Emerson. (shrink)

The object of this paper is to show why recent research in the psychology of deductive and probabilistic reasoning does not have.