LEWISS,C.I. CALCULUS OF PREDICATES

In 1951 C. I. Lewis published a logic of general terms (or properties) that he called the calculus of predicates. Although this system is of less significance than Lewis's earlier work on propositional modal lo gic, it has considerable historical interest and does not deserve the almost total neglect it has received. My aim here is to situate this s ystem in the context of Lewis's earlier work and to examine several of its central features. After sketching the historical background, I pr esent the syntax of Lewis's system, discuss his reasons for preferring it to quantified modal logic, and develop a semantics for it that is suggested by Lewis's informal discussion of his system together with h is general views on meaning. I then discuss Lewis's sketchy extension of his system to include quantifiers and examine his claim that it can serve as a foundation for logic in general. I conclude by noting two minor changes in CP that, from today's vantage point, would count as i mprovements.