In this context the inference metaphor is nothing new. Roughly 100 years before the inference revolution, the inference metaphor had already been introduced to explain the mechanism of object perception, in the guise of Hermann von Helmholtz's notion (1856-66/1962) of "unconscious inferences." Neo-Helmholtzians such as R. L. Gregory (1980) complain that Helmholtz's lead was not followed for a century or more. Instead the focus was on physiological theories and on Gestalt theory, which Gregory calls the "Dark Age." However, it is only partly true that unconscious inferences were neglected for almost an entire century. Between 1930 and 1950, Egon Brunswik transformed the meaning of Helmholtz' unconscious inferences into unconscious multiple regression statistics. Brunswik's conception, however, was rejected by the community of experimental psychologists at the time. Brunswik's "intuitive

These "inferences" posed something of a problem to Helmholtz. He was a great admirer of John Stuart Mill (1846) whose Logic he often quoted, and he believed that the conscious process one uses in making inductive inferences about the world had a parallel at a different cognitive level, where words were not required. In the first version of the Optics (1856-1866/1962) he called these unverbalized inductions "unconscious inferences" (unbewusste Schliisse); later he was attacked because his critics thought that, by definition, an "inference" had to be the result of a conscious, verbal process. Moreover, Schopenhauer had used the words quite differently in a way from which Helmholtz wished to disassociate himself (see Schopenhauer, 1918/1966, pp. 135-136). Nevertheless, at the end of his life, in his Founder's Day address at the University of Berlin, Helmholtz (1879/1968) decided to stay with his original term because he believed that when we make an unconscious inference about what we perceive, it has the same spontaneity and impressiveness as a raw sensation itself, and furthermore is not open to introspective analysis.