Rhetoric is useful because the true and the just are naturally superior to their opposites, so that, if decisions are improperly made, they must owe their defeat to their own advocates; which is reprehensible. Further, in dealing with certain persons, even if we possessed the most accurate scientific knowledge, we should not find it easy to persuade them by the employment of such knowledge. For scientific discourse is concerned with instruction, but in the case of such persons instruction is impossible.
AristotleThe ridiculous is produced by any defect that is unattended by pain, or fatal consequences; thus, an ugly and deformed countenance does not fail to cause laughter, if it is not occasioned by pain.
Aristotle