Bergson believes that comedy is the opposite of tragedy because the latter relates to the emotions, and the former relates to the intellect. We can laugh at someone we pity or feel any strong emotion for, but we must first subvert these sentiments so as to view that person as an object. Bergson also gives the example of "ugliness" as a case where the intellect can stifle laughter. When we see something ugly, we can only find it amusing in the first instant, in the spontaneous and thoughtless response to it. Once we stop to consider its ugliness, we come to see it as an object of intellectual distaste, not of humor.

Comedy is, in Bergson’s mind, the province of humanity alone. We don’t laugh, for example, at buildings or at natural rock formations, and while we do sometimes laugh at animals, this is more often than not because they are exhibiting some recognizably human behavior. Furthermore, Bergson links comedy to human beings’ natural disposition toward sociability, in that it is far easier to laugh together as a group than it is to laugh all alone. For Bergson, the essential "cause" of comedy is the mechanical aspect of life, when the natural flux of human life is shown up or interrupted—for example, a man falling over while running. The reason we find imitation or parody funny is that the imitator is performing in a very mechanical fashion that which was not originally intended as mechanical.

Comedy for Bergson has a distinct moral and social purpose. The reason we laugh at those who appear eccentric is because they are engaging in non-social behavior and are thus threatening our sense of stable, socially proper behavior. To appear comic is the crime, and laughter is the punishment. But Bergson suggests that as much as laughter punishes eccentricity, it also punishes rigid conformity as an over-mechanical imitation of what we see as the fluid nature of our lives.