That's A Good One, Plato

Even wit is educated insolence, thought Aristotle, Plato's student. During Aristotle's time, comedy was less vulgar and obscene than the comedy which disgusted Plato. 

Aristotle considered this comedy play or amusement. "Life includes rest as well as activity," he said in the Nicomachean Ethics, "and in this included leisure and amusement." 

Aristotle believed that we needed leisure and amusement because we cannot devote ourselves entirely to work and seriousness. The value of humor for Plato, in his Poetics, was such: 

Comedy...is in imitation of people who are worse than average. Their badness, however, is not of every kind. The ridiculous, rather, is a species of the ugly; it may be defined as a mistake or unseemliness that is not painful or destructive. The comic mask, for example, is unseemly and distorted but does not cause pain. 

Aristotle considered an overindulgence in humor, as well as the inability to engage in it, as a vice: 

Those who carry humor to excess are thought to be vulgar buffoons, striving after humor at all costs, and aiming more at raising a laugh than at saying what is becoming and at avoiding pain to the object of their fun; while those who can neither make a joke themselves nor put up with those who do are thought to be boorish and unpolished. 

According to aristotle, you have eutrapelia or ready-wittedness, if you engage in humor to the right degree, and at the right time and place. You don't have to be a comedian to know that timing is everything.