The private interest of the individual would not be sufficiently provided for by reasonable and cool self-love alone; therefore the appetites and passions are placed within as a guard and further security, without which it would not be taken due care of.
Joseph Butler (1856). “The analogy of religion, natural and revealed, to the constitution and course of nature: to which are added, two brief dissertations : On personal identity, and On the nature of virtue; and fifteen sermons”, p.432
