The Nature of Logic

Abstract

How does Frege conceive of logic, if not in modal terms? For Frege, logic is a system of truths that divides into primitive truths, which are axioms or basic laws, and logical truths justified by primitive logical truths. Frege appears to hold that what makes a thought a primitive logical truth is that it provides its own justification. However, Frege appears also to give arguments for the basic laws of Frege’s systems of logic. I argue that these arguments cannot be understood as non-question-begging demonstrations that the basic laws are self-justifying. Knowledge of self-justification results from the exercise of a perception-like capacity, and Frege’s “arguments” are intended to provide his readers with the occasion to exercise this capacity with respect to the thoughts expressed by his basic logical laws.