More on educational equity
Richard Chappell takes issue with my suggestion that people who favor progressive taxation and national health care should also put a premium on helping the least proficient students rather than gifted students. His main point is that there are other reasons besides egalitarianism or Rawlsian social justice to favor progressive taxation and national health care, and these reasons (e.g., utilitarianism) don't necessarily favor focusing on the least proficient students. So basically believing in the former needn't require believing in the latter. That's fair enough.
But I do want to clarify what I meant in the previous post. I was working off Rawls's Difference Principle, that inequality is justified only insofar as it benefits the least well-off. This leaves room for all sorts of qualifications on the claim that we should focus our effort on the least proficient students. For example, gifted students are likely to become scientists, engineers, intellectuals, or entrepeneurs who create innovation and therefore benefit everyone, even the least well-off. (This being analogous to a Rawlsian argument why capitalism is better than socialism, even for the poor.) Or, a focus on mediocrity rather than excellence is a kind of "soft bigotry of kind-of-low expectations" that leads to a general devaluing of education.
Richard also mentions a couple issues I should discuss. Richard brings up the idea of cost-efficiency - that it's less cost-effective to educate less-able students (ie less able students require more effort to get X improvement in education than gifted students), or that you might get more utility out of education the more educated you are (ie gifted students get more enjoyment out of X improvement in education than mediocre students). Aside from questioning the latter suggestion (it's quite plausible that increased intelligence actually makes you less happy), I must disagree even on principle - I think a decent society must, to some extent, give priority to the least well-off [with the Rawlsian qualification that inequality can also help the least well-off], even if this is cost-inefficient. Just think how much extra money we spend on special education - I'd have a hard time arguing that giving disabled students extra attention is wasted money.
I'm sympathetic to Richard's view that intellectual excellence is "an intrinsically valuable mode of human flourishing" (as opposed to material or medical "excellence"). However, I have trouble justifying it and suspect that intellectual excellence is actually instrumentally valuable, in that geniuses discover new scientific theories, create great works of art, and so on. Certainly, it is in some sense better to have a hermit genius who doesn't try to discover new things than a hermit of mediocre intelligence who also doesn't try to discover new things, but it's not clear to me that the former is so much better than the latter that we should spend any money on it.
Anyway, with all these qualifications, it might even be that the current system doesn't give enough attention to gifted students. Given how hard it is to disentangle the facts of the matter (how much do you weigh this gifted student's future discovery of cold fusion against this less-able student's inability to get a decent job?), it's not clear that this discussion has any actual policy implications. But I suppose it's worth discussion anyway, if only to sharpen the tensions between equity and excellence.