Wit (n.) is a readiness to turn this way and that; jokes are movements of character, and characters, like bodies, are known by how they move.
Wit (n.) has two sides: the knack of jesting in good taste and the ability to stand being jested at — the boor can do neither, and gets angry.
Wit (n.) has no definition, Aristotle held, since what delights one hearer repels another; a joke manual, like a rulebook for virtue, does both too little and too much.
Wit (n.) is to jokes what a healthy appetite is to food: the boor is squeamish and takes nothing comic, the buffoon omnivorous and takes everything — and the true wit pleases a good judge even when the joke is on himself.