Daniel Algom William S. Cain John B. Pierce Foundation Laboratory and Yale University
All students of Western philosophy are familiar with the term mental chemistry conceived within the British tradition of associationism in the nine- teenth century. The notion that elements of thought (i.e., sensations and their copies, ideas) interact to form new complex ideas, just as chemical elements combine to produce new mixtures and compounds, was suggested in 1820 by Thomas Brown in his Lectures (cf. Murray, 1988). Nine years later, James Mill, in his Analysis, advanced a closely related concept by the name of inseparable ideas. But it was left to his son, John Stuart Mill, to develop these notions about mental mixtures or complete fusion of mental elements (such that the resultant idea is different from the elements that made it up) more fully into a more coherent theory denoted by the new famous mental chemistry. In a substantive vein, the cognitive processes implied by J. S. Mill's analysis (in his Logic of 1843) were readily embraced by the newly emancipated science of psychology on the Continent. Wundt would use the terms mental elements and mental compounds fairly frequently (characteristically, perhaps, without attribution). Later, many of the same ideas reappear in Gestalt psychology (cf. Hergenhahn, 1986) as well as in modern cognitive psychology.
Given that venerable tradition, it would seem quite imprudent, not to say impudent, to evoke the same metaphor to signify a different, though, to be sure, not completely unrelated referent. Yet we submit that, in this case, one should follow exactly this venture: The experiments described in this chapter are best summarized as probing the cognitive processes