Relevant to the post below; from Utilitarianism, chapter five:
To have a right, then, is, I conceive to have something which society ought to defend me in the possession of. If the objector goes on to ask, why it ought? I can give him no other reason than general utility. If that expression does not seem to convey a sufficient feeling of the strength of the obligation, not to account for the peculiar energy of the feeling, it is because there goes to the composition of the sentiment, not a rational only, but also an animal element, the thirst for retaliation; and this thirst derives its intensity, as well as its moral justification, from the extraordinary important and impressive kind of utility which is concerned. The interest involved is that of security, to every one’s feelings the most vital of all interests. All other earthly benefits are needed by one person, not needed by another; and many of them can, if necessary, be cheerfully foregone, or replaced by something else; but security no human being can possibly do without; on it we depend for all our immunity from evil, and for the whole value of all and every good, beyond the passing moment; since nothing but the gratification of the instant could be of any worth to us, if we could be deprived of anything the next instant by whoever was momentarily stronger than ourselves. Now this most indispensable of all necessaries, after physical nutriment, cannot be had, unless the machinery for providing it is kept unintermittedly in active play. Our notion, therefore, of the claim we have on our fellow-creatures to join in making safe for us the very groundwork of our existence, gathers feelings around it so much more intense than those concerned in any of the more common cases of utility, that the difference in degree (as is often the case in psychology) becomes a real difference in kind. That claim assumes the character of absoluteness, that apparent infinity, and incommensurability with all other considerations, which constitute the distinction between the feeling of right and wrong and that of ordinary expediency and inexpediency. The feelings concerned are so powerful, and we count so positively on finding a responsive feeling in others (all being alike interested), that ought and should grow into must, and recognised indispensability becomes a moral necessity, analogous to physical, and often not inferior to it in binding force.
The argument here is fairly straightforward: we need our basic interest in security to be protected because it is the precondition of pursuing any other interest whatsoever. Thus, simply on utilitarian grounds, it makes sense to assign a higher status to this interest to ensure that it’s protected. Otherwise, no one could pursue any worthwhile projects without constantly looking over their shoulder and having to be on guard against their fellow man. (There are shades of a social contract account here.) Mill can, he thinks, account for the importance we attach to certain rights without needing to ground them in anything other than the principle of utility. I’m not 100% convinced that he’s correct here, but I do think there’s something persuasive about the idea that rights are grounded in the protection they provide to certain vital interests.