One of Sonia Sotomayor’s lower-candlepower remarks was the one about a Latina judge making a better decision yada yada, [UPDATE: this is too flip, as Brad Delong notes and I discuss in this post] to which the franticosphere has clung as to a slippery rock in a Class V river, and with as little success. Stupid and unconstructive as is their leap from this misfire to “she’s a racist!” it’s not the main problem with the deliberation over her appointment. [I must digress a little here, to admire Obama’s ability to throw the Republican noisemakers concrete life preservers, again and again; they just can’t stop themselves from grabbing these things and sinking in a single news cycle…amazing.]
What the discussion of diversity on the court, appointing a woman (partly) because of her sex, and the like is missing is the distinction between intensive and integral, or ensemble, properties. The difference is very important in physics, for example when we think about a piece of material being “iron” or “hot” or having a velocity. Ironness and velocity are intensive properties that can be predicated of any part of a horseshoe, right down to a single atom. But temperature is not like that; it’s only meaningful in regard to a large ensemble of atoms that can have an average random speed of vibration, without a net velocity in a particular direction. A single atom can be going somewhere, but it cannot be hot or cold. Or purple.
If you don’t like thermodynamics, think of this distinction as a figure-ground issue. If you didn’t have an environment, you couldn’t have a self. An orange has lots of intrinsic qualities, but “feminist” is not one of them: it’s an integral property of a seder plate with an orange on it, but not of a fruit bowl with the same orange.
Diversity is not predicable of a person, only of an ensemble. A person added to an ensemble can increase its diversity (the variance of whatever properties one wishes to note, like “life histories” or skin color), but not because she brings any intrinsic diversity. Sotomayor will make the current Supreme Court more diverse in important ways when she arrives for work; Sotomayor will not diversify her Abogados Bronxiqueñas reunion dinner that same evening. It’s not an intrinsic property of any single appointment that should be of interest here (of course smart, educated, wise and the like are important intensive qualities) but the quality of the court as an ensemble.
Here diversity is extremely important. The limiting case is nine clones of your favorite justice ever: eight of them won’t add enough insight to the first to be worth the cleaning bills for their robes. My best boss ever was thus largely because he would never hire anyone not smarter than himself in at least one important way, and would never hire anyone like someone he already had on the team, where “like” covered things like professional qualification, social background, sex. age, and Rolodex. The idea of “a good Assistant Secretary” simply didn’t mean anything for him except with reference to gaps in the existing squad. So what I hope Sotomayor meant was that a group of judges, other things being equal, that had (for example) a smart Latina in it would make better decisions than one without. Obama is absolutely correct to resist the idea of choosing someone merely on a mechanistic scoring of intrinsic qualities, and to count the increment in (for example) ethnic and sex diversity of the institution heavily. It’s not so much that anyone’s personal history is especially better than anyone else’s, it’s whether it adds to the resources already on hand.