In what follows, I try to clarify historically the idea of the third in philosophy and in psychoanalysis. It is an account that has its own point of view, the evidential justification of which, of necessity, is only scantily presented. The exposition suggests an agreement and differences between the various philosophical thirds and the psychoanalytic thirds found in this issue. Even the agreement that emerges is at present controversial. I make no claim that this exposition of the topic escapes the influence of the controversy. My purpose is to provide background and to raise questions.