The Irrelevance of Aggregate Differences to Cartesian Individualism
Addressing a common challenge to radical equality between the sexes.
A common challenge to the assertion that all individuals share essentially the same mental substance is an empirical challenge invoking aggregate differences in cognitive abilities. For example, a sex essentialist might assert that women perform +/-X% at Y cognitive exercise, ergo women possess an essentially different mind than men. Prima facie, this actually sounds like a plausible challenge to Cartesian Individualism. Upon slightly closer scrutiny, this argument holds no water.
This essentialist claim can be debunked rather easily. Imagine two men—or any set of individuals who share the same immutable physical characteristic being scrutinized—whose performance on a particular mental task is measured. One man does better than the other. One might conclude from this data that the one man’s brain has been better trained or is innately superior at certain feats than the other’s. What one would not conclude is that these men’s mental substances are essentially different.
Likewise, if the same test were conducted between a man and a woman, and a differential existed, it would be causally dubious to attribute this difference to an essential difference in male and female minds. The reality of essential physical differences between men and women (whose existence is so trivial/obvious that I will not expound on this point) is not evidence of essential differences of the mind. There is no such difference; the immaterial substance of the mind cannot be differentiated by sex, race, or any other physical grounds. To do so would be to commit a category mistake, e.g., the color red sounds feels dry. The essence of color is visual, not physical.
Ayn Rand expresses a related appreciation for individualism in her 1964 philosophical work, The Virtue of Selfishness:
A genius is a genius, regardless of the number of morons who belong to the same race—and a moron is a moron, regardless of the number of geniuses who share his racial origin.1
Essentializing individuals minds/souls/essential substance to their physical attributes is a fallacious. Moreover, statistical aggregates tell you nothing about the individual with whom you’re engaged. All individuals, therefore, must be treated as possessing the same mental essence.2
Source: https://quotepark.com/quotes/954146-ayn-rand-a-genius-is-a-genius-regardless-of-the-number-of/
Not to be confused with the same cognitive capabilities. For example, my brother and I have divergent mental acuities and bases of knowledge but have, like all human beings, essentially the same mental substance.