This is an essay about a love affair with an idea: “What do human beings really want?” and the biography of that idea in the recent history of American psychology, including the autobiography of my own idea. I offer it not only as history, but as a contribution to understanding. Understanding not only of the nature of motivation, but of motivation as a vehicle of what I have called the psychology of knowledge (Atwood & Tomkins, 1976; Tomkins, 1963b, 1965a). This is a field that would concern itself with the personal as well as social influences on the ebb and flow of affect investment in ideas and ideology, in methods and styles of investigation, and in what are considered acceptable criteria of evidence. By ideology I mean any organized set of ideas about which human beings are at once both articulate and passionate and about which they are least certain. At the growing edge of the frontier of all sciences there necessarily is a maximum of uncertainty, and what is lacking in evidence is filled by passion and faith and by hatred and scorn for the disbelievers.