Domare Oliver Wendell Holmes (i artikeln ”Natural Law” i Harvard Law Review, 1919):
Deep-seated preferences cannot be argued about — you cannot argue a man into liking a glass of beer — and therefore, when differences are sufficiently far reaching, we try to kill the other man rather than let him have his way. But that is perfectly consistent with admitting that, so far as appears, his grounds are just as good as ours.
Helt riktigt. Värderingar är subjektiva och går ytterst inte att rubba med rationell argumentation, eftersom de inte kan vara sanna eller falska.