Stoppard (1998) in his great play “The Invention of Love” has suggested that the love poem “Like everything else, like clocks and trousers and algebra … had to be invented” (emphasis added). In this essay I argue that the concept of Purgatory was not always with us either, but also had to be invented. If theology got the concept started, I suggest that eventually it may have found its way into psychology, even influencing psychoanalytic ideas about the origins of the Superego. If the concepts Heaven and Hell reflect primitive Superego absolutes, the concept of Purgatory seems like the primitive Superego modulating its own severity and becoming more mature in the process. This influence of a theological concept (Purgatory) on a psychoanalytic concept (Superego) is then outlined and explicated in some detail.