Non-voluntary sterilization

We cannot easily condemn in principle a policy where people are non-voluntarily sterilized with their informed consent (where they accept sterilization, if they do, in order to avoid punishment). There are conceivable circumstances where such a policy would be morally acceptable. One such conceivable circumstance is the one (incorrectly, as it were) believed by most decent advocates of eugenics in the late nineteenth and early twentieth century to exist: to wit, a situation where the human race as such is facing a threat. Perhaps today's Chinese experience with a threat of over-population is a more realistic example? Finally, there is some room for a kind of non-voluntary (and coercive) sterilization without informed consent. I think of people who are severely mentally retarded, and who cannot understand how sexual intercourse relates to conception. If some of these persons are fertile and sexually active, it may very well be the morally right thing to do to sterilize these persons, in their own best interest, but without their consent--if necessary even through coercive means.