Categories often exert a tyranny over our perceptions and judgments. An old joke— perhaps it even happened—from the bad old days of McCarthyism tells of a leftist rally in Philadelphia, viciously broken up by the police. A passerby gets caught in the melee and, as the cops are beating him, he pleads: “Stop, stop, I’m an anticommunist.” “I don’t care what kind of communist you are,” says the cop, as he continues his pummeling.
We seem to think by dichotomies and separations. Protagoras asserted, according to Diogenes, “that there were two sides to every question, exactly opposite to each other.” We set up our categories, often by arbitrary division based on tiny differences; then, mistaking names for moral principles, and using banners and slogans as substitutes for reason, we vow to live or die for one or the other side of a false dichotomy. The situation is lamentable enough when the boundaries are profound and natural; if cows declared war on chickens, we might deplore the barnyard carnage, but at least the divisions would be deep, and membership by birth could not be disputed. But when humans struggle with other humans, the boundaries are almost always fluid and largely arbitrary (or at least a curious result of very recent historical contingencies). If we are so prepared to base our struggles on group identification, we should at least try to understand (and maybe even to improve) our methods of classification.
We do not ponder the bases of our classifications with sufficient scrutiny. Taxonomy, or the study of classification, occupies a low status among the sciences because most people view the activity as a kind of glorified