This article begins by examining the bad reputation humor traditionally had in philosophy and education. Two of the main charges against humor--that it is hostile and irresponsible--are linked to the Superiority Theory. That theory is critiqued and two other theories of laughter are presented--the Relief Theory and the Incongruity Theory. In the Relief Theory, laughter is a release of pent-up nervous energy. In the Incongruity Theory, humor is the enjoyment of something that violates ordinary mental patterns and expectations. The development of the Incongruity Theory is traced in thinkers like Aristotle, Kant, Schopenhauer and Kierkegaard, and refinements are suggested to the theory. The Incongruity Theory, it is argued, helps us to appreciate the affinity between philosophy and humor, especially the genre known as stand-up comedy. The article concludes by using Robert Nozick's analysis of wisdom to show how dramatic comedy embodies practical lessons for living well.