Amanda Doerty, arguing for the intrisic immorality of theft, asks:

If, in any situation, we find it justifiable for any person or group to take the property of any other person without the consent of the other (whether by force, or threats of jail, etc.), we cannot argue that there is anything intrinsically wrong with that act. On what, then, do we base our objections to theft?

She dismisses the utilitarian answer thus:

Pure utilitarianism is of course impossible—you can’t know what serves the ‘greater good’ unless you have some conception of what that greater good is, and it obviously won’t work out too well if every single person gets to decide what he or she thinks the greater good is. ‘Happiness’ is often proposed, or ‘life,’ or something similarly vague. The difficulty of deciding how one would measure such things is problematic enough for the utilitarian route, and there is always the question of why a certain criteria should be used. Not only that, but for those people who do not personally benefit from serving the greater good, there is no compelling reason to do it anyway.

In any case, you can’t really hold on to a utilitarian ideal if you believe that individuals have certain unalienable personal rights, since those rights will likely be often violated if every one always acts for the ‘greater good.’ For those of us who want to hold on to the idea of individual rights, that is probably enough reason to stay away from utilitarianism.

As a card-carrying utilitarian, I feel compelled to respond.

First, a purely definitional matter. Classical utilitarianism, a la Bentham, certainly does have a “conception of what the greater good is”: pleasure is the good, and pain is the bad. Nothing vague about that. Some contemporary utilitarians define utility in terms of preference satisfaction, which comes close to “every single person gets to decide.”

Hard to measure? Yes. But do we have any reason to think that figuring out the right thing to do will always be easy? As for “the question of why a certain criteria should be used,” I don’t see how natural rights theories fare much better in this regard. The Kantians claim to have an answer, but that's responding to the Kantians is beyond the scope of this blog post.

And the only ethical theory that can provide a compelling reason for everyone to follow it is ethical egoism. As nice as it would be to have the ethical coextensive with the rational, I can’t see any reason to think that it must be.

Amanda is correct, though, that pure utilitarianism is incompatible with “inalienable rights.” But even if people do have “inalienable rights,” it doesn’t follow that the utilitarian answer isn't the correct explanation of the wrongness of theft. It seems to me that the strongest candidates for inalienable rights are rights to control one’s own body: the right not to be killed, the right get a tattoo, the right to injest whatever sort of intoxicating substance one pleases. There’s a big leap from those to general property rights. So perhaps a rights-based explanation is the correct explanation for the wrongness of murder, but a utilitarian explanation is the right explanation for the wrongness of theft.