I think I unhelpfully ran a few ideas together in the post on libertarianism that should be more clearly distinguished. First, there is the distinction between “negative” and “positive” rights. That is, I asserted that, in practical political terms, this distinction is fuzzier than often imagined because the protection of any right–positive or negative–requires dedicated resources. For example, my right to life isn’t a mere claim against others not to kill me, but something that we think society is obliged to take positive steps to protect (via laws, police, courts, etc.). Similarly with other rights. So, the distinction between a “negative” right to life and a “positive” right to, say, welfare does less work than libertarians sometimes suppose.
The second issue, which I didn’t adequately distinguish, is how rights are justified in the first place. A consequentialist justification would be that, all things considered, having a society that protects certain rights will, over the long run, result in a balance of good over evil consequences (bracketing the question of what “the good” consists in). As Mill said, they are the precondition of our pursuing any worthwhile projects. A deontological justification, on the other hand, would be that people (and possibly other animals) have rights simply in virtue of the kinds of beings they are. Specifically, they cannot be used merely as means for the benefit of others. Or one might say that they have the right to freedom and well-being, independently of any value they may contribute to others.
I’m more amenable to deontological arguments than the post made it sound. Indeed, I think my main point–that strict (anarcho-) libertarianism has unacceptable consequences–could be couched in more deontological terms. If human beings have certain rights in virtue of the kinds of beings they are, then a just society is one, at least, in which those rights are adequately protected. My claim was that the anarcho-libertarian utopia will not adequately protect rights because, inter alia, the rights of the weak and dependent would be dependent on either their ability to pay or on the charity of others. Moreover, if one of the rights that people have is access to the basic goods which are the precondition of any meaningful life, there are good reasons to think that a thoroughgoing laissez-faire regime would also fail miserably at securing those rights.