A sense of humor is a measurement of the extent to which we realize that we are trapped in a world almost totally devoid of reason. Laughter is how we express the anxiety we feel at this knowledge.
Source, in full
Originally published in "Encyclopedia Tropicana: A Reference Book for the Modern World, Volume 1" by Joel Achenbach, The Miami Herald, May 4, 1986; quoted by Bryan Curtis, "Dave Barry: Elegy for the humorist," Slate, January 12, 2005