I've been reading The Comic Mask in the Commedia Dell'Arte by Antonio Fava. Here's a direct quote:
"[Theatre] instantly organizes itself in means, ways, and genres, all of which are aimed at catharsis, at purification, at overcoming anguish. Serious, tragic, dramatic theater offers thoughtful, moving, and intimate relief. Magic theater reassures without openly explaining why but effectively spreads the sensation of having escaped from something terrible. Epic-heroic theater allows us to participate in unforgettable triumphs. Mystical theater saves us through spiritual elevation or the superiority of thought. But above all, comic theater discharges anguish with an efficacy and rapidity unknown to the other genres.
It's curious, this condition of superiority of the inferiority of the comic. The aim is high: complete catharsis, purification, relief from anguish, but the means of attaining this catharsis are low. In fact, they are the very meanest. That's the natural state of the comic character. "
"Comedy literally shatters fear, releasing collective joy expressed in raucous, liberating, communal laughter. The comic actor neither arouses emotions nor raises questions. Rather, by exposing them to destruction, he resolves them. The laughing spectator is relieved. He is saved."
"The sacredness of laughter renders the laugher immortal. He who laughs is immortal. Certainly, it is only a brief immortality, lasting the duration of the the laugh itself, but with certainty that the laugh, and with it, immortality, will be repeated. To the long and tormented catharsis of tragedy, comedy opposes an irresistible, brief, intense series of catharses, loudly expressed by the whole assembly."
This is why I love theater.