Abstract
The concept of knowledge, more than any other, has invited truth-functional analysis. In saying of a person that he knows that p, we are, according to many philosophers, saying no more and no less than three or four distinct things. In spite of setbacks suffered by the “traditional” analysis, the belief remains strong that there is a definitive answer to the question “What is knowledge?” in truth-functional terms. Yet the word ‘know’, like most others having to do with human beings, is used for a variety of purposes in a variety of situations. It would be surprising if all these uses could be captured in a single formula.