The book Human Enhancement is finally out.  My chapter is second to last, just after a thoughtful one by Daniel Wikler:

It is often observed that mildly or even moderately retarded people do not seem dull to themselves as long as they stay on the farm (rather: certain farms), but become so immediately when they move to the city.  Here the relative difference between a dull or not-very-bright minority and the majority who are just below average, or better, becomes important, and as that majority arranges society to suit themselves, their less-bright peers become incompetent. …

Those who are rendered incompetent in this manner need supervision, and in order to protect them in that now-dangerous environment, their rights are taken away.  Humane regimes strive to protect as uch of their range of free choice as possible, consistent with the need to protect them from serious or irremediable harm (and to protect others), but there is no supposition that everyone has a natural, inalienable right to self-determination  that would rule out all configurations of the social and physical environment that are disadvantageous to the less-talented. …

What, then, would be the effect of selective enhancement of intellectual capacity – that is, enhancement of some, but not all – for the social and political world that we "normals" would inhabit?  Would it erode the foundations of egalitarianism, undermining the claims of many who now hold title ans citizens to that equal status?  Would those made or engineered to be born smart be within their rights to deprive the rest of our rights, presumably with a humanitarian intent?  In a word: yes. … 

Should we be eternally vigilant and suspicious of people who appoint themselves "guardians", profess humanitarian motives, and then take over our lives?  Or do the shoes just hurt because they would be on our feet?

This is a great test case for paternalists; if you feel that your superior minds justify ruling the lives of others, would do you accept having your life ruled by future folk with greatly enhanced minds?