On the Application of Logic to Certain Philosophical Questions

This talk will focus on various aspects of the relationship between logic and philosophy, including the extent to which the logical frameworks we develop presuppose an ontology, the extent to which logic is free of existence assumptions, and the extent to which set theory succeeds as a tool for understanding language. In a series of case studies I will describe, among other things, how analytically true principles of logic can have synthetically true consequences, how logical and analytic truths can fail to be necessary, how the `philosophically proper' choice of semantics for modal logic has the consequence that simple propositional modal logic is not an intensional logic, and how to interpret comprehension principles in a way that may be consistent with the view that meanings of expressions are constituted by their use or by their inferential roles. Finally, I will discuss some of the recent successful applications of logic to philosophical problems, and indicate a few of the obstacles we face in the attempt to use logic to investigate philosophical questions.

Edward N. Zalta