Time is nature's way to keep everything from happening all at once.

Wheeler quoted this saying in Complexity, Entropy, and the Physics of Information (1990), p. 10, with a footnote attributing it to "graffiti in the men's room of the Pecan Street Cafe, Austin, Texas". Later publications, such as Paul Davies' 1995 book About Time (p. 236), credited Wheeler with variations of this saying, but the quip is actually much older. The earliest known source is Ray Cummings' 1922 science fiction novel The Girl in the Golden Atom, Ch. V: " 'Time,' he said, 'is what keeps everything from happening at once.' " It also appears in his 1929 novel The Man Who Mastered Time. The earliest known occurrence other than Cummings is from 1962 in Film Facts: Volume 5, p. 48.