ABSTRACT
In this chapter I argue for a connection among modality, pragmatism, and the a priori in C. I. Lewis’s philosophical development. First, I show that Lewis’s criticism of Bertrand Russell’s material implication rests on showing how the logic of material implication, by itself, is incapable of accounting for a central aspect of the usefulness of deductive reasoning. This aspect involves a certain kind of priority of our knowledge of logical principles to knowledge of empirical claims to which logic is applied. Lewis champions the modal principles of the logic of strict implication because they are capable of accounting for their own apriority in this sense. Second, I show that from this position Lewis was not able to advance to a fully pragmatic conception of the a priori without an answer to Josiah Royce’s doctrine of absolute, non-pragmatic, logical principles identifiable by their being “re-instated” through their denial. After publishing A Survey of Symbolic Logic, Lewis came to think that he has an argument for showing that Royce’s “re-instatement through denial” criterion is satisfied by all systems of logic. I conclude by raising some doubts about the success of Lewis’s argument, pointing to some issues on the limits of pragmatism for further examination.
