The term Weltanschauung, literally, "view of the world," had a very specific meaning for Freud, who defined it in the New Introductory Lecture as follows: "A Weltanschauung is an intellectual construction which solves all the problems of our existence uniformly on the basis of one overriding hypothesis, which, accordingly, leaves no question unanswered and in which everything that interests us finds its fixed place" (1933a [1932], p. 158).

Indeed Freud had already used this concept as a stick with which to beat philosophies and religions—both lambasted, for example, in his Future of an Illusion (1927c). In 1933, however, he broadened the notion, bringing science too under its aegis; this with the proviso, though, that "the Weltanschauung of science already departs noticeably from our definition. It is true that it too assumes the uniformity of the explanation of the universe; but it does so only as a...