To what shall the character of utility be ascribed, if not to that which is a source of pleasure? - Jeremy Bentham

Intense, long, certain, speedy, fruitful, pure—
Such marks in pleasures and in pains endure.
Such pleasures seek if private be thy end:
If it be public, wide let them extend.
Such pains avoid, whichever be thy view:
If pains must come, let them extend to few.

Rights are, then, the fruits of the law, and of the law alone. There are no rights without law—no rights contrary to the law—no rights anterior to the law. Before the existence of laws there may be reasons for wishing that there were laws—and doubtless such reasons cannot be wanting, and those of the strongest kind;—but a reason for wishing that we possessed a right, does not constitute a right. To confound the existence of a reason for wishing that we possessed a right, with the existence of the right itself, is to confound the existence of a want with the means of relieving it. It is the same as if one should say, everybody is subject to hunger, therefore everybody has something to eat.

[P]leasure is in itself a good; nay, even setting aside immunity from pain, the only good: pain is in itself an evil; and, indeed, without exception, the only evil; or else the words good and evil have no meaning. And this is alike true of every sort of pain, and of every sort of pleasure.