Why we shouldn't chemically castrate sex offenders

NZPols objects to my post on Phil Goff's interest in castrating sex-offenders, on the familiar Consequentialist basis of "if it works, why not do it?"

The answer, of course, is that it would be a gross violation of the subject's human rights. NZPols doesn't think that this matters, but as a liberal, I do. Axiomatic differences in ethical theories, I guess. Anyway, for people wondering why I'm objecting so violently to this, here's a quick outline:

Human rights (and, to a lesser extent, preference-based consequentialisms) are ultimately based on the idea that individual autonomy - "the capacity to be one's own person, to live one's life according to reasons and motives that are taken as one's own and not the product of manipulative or distorting external forces" - is valuable. In order to protect this autonomy, we enforce a wide sphere around the individual where the State is forbidden to interfere. Prohibitions on government interference in people's choices of religion or relationships, for example, exist because these things are vitally important to people's life-plans and their sense of self.

Before people get the wrong impression, I am not arguing that the autonomous choices of paedophiles to rape children must to be respected; Mill's principle that interference is justified in order to punish or prevent harm to others deals with that quite handily. What I am arguing however is that the respect for autonomy on which a liberal society is based necessarily entails that those punishments or preventative measures should interfere as little as practicable with a criminal's autonomy. So, we can imprison criminals, and offer them non-coecive rehabilitation, but we cannot (for example) forcibly brainwash them into being obedient, law-abiding citizens (even though the results would probably be better for everyone if we did).

Needless to say, forcible medical treatment - whether surgical or chemical - is about as invasive of individual autonomy as you can get. Forcible treatment to modify people's desires is even worse. I can think of no better example of treating people like animals - or, in Kant-speak, as means rather than ends - than that.

(Why the concern with the rights of sex offenders? Because human rights are by their nature universal, and in order to claim them for myself, I have to also defend them even for the worst among us. How is my stance on this different from my mocking Libertarians for their "blind worship of private property rights"? Because property is a tool, not a core human right...)