On the Logic of Perception

Abstract

Should the title of this paper prompt you to ask, “What is the logic of perception?”, there is an answer at hand. I shall argue here that the logic of our perceptual terms is a branch of modal logic.¹ In saying this, I mean by ‘perceptual terms’ both such words as ‘sees’, ‘hears’, ‘feels’, etc., which involve a reference to one particular sense modality, and such words as ‘perceives’, which are neutral in this respect. By modal logic, I mean not only the logic of the terms ‘necessary’ and ‘possible’ but also the logic of all the other terms that can be studied in the same ways as they. Among these terms are most of the words that are usually said to express propositional attitudes, including ‘knows’, ‘believes’, ‘remembers’, ‘hopes’, ‘strives’, etc. What is in common to all the modal notions in this extended sense of the term will be partly explained later.²