THE BASIC IDEA

Aristotle observed that when we thought of one thing we were led to think of similar things. He was certainly right. It seems natural to say that ice cream is like sherbet, and that ice cream is more like sherbet than it is like pizza! Most of the time judgments of similarity are made almost without thought.

Categorical thinking is an equally natural thing to do (and Aristotle noted this, too). We speak of how to deal with DOGS, without necessarily referring to a particular dog. A good meal is supposed to have an entrée, green vegetables, and a starch. A politician may be categorized as a typical Republican, Democrat, or Socialist. We use such categorizations in our reasoning, by imputing characteristics of a class to characteristics of an individual. In 2002, my representative to Congress was a woman and a Republican (The Hon. Jennifer Dunn). You could immediately impute characteristics of the class to Rep. Dunn: guessing (correctly) that she was a fiscal and social conservative but, because she is a woman, being less sure that she espoused the anti-birth-control rhetoric of some members of the Republican Party at that time. (She did not.) As Aristotle noticed once again, objects are grouped together into classes because they are similar to each other in some way, although wide variation may be permitted in other ways. Continuing with my example, knowing that Rep.