A timeless guide to laws and principles that can help us make decisions and navigate the chaos of everyday life.

There are laws of nature—like gravity, thermodynamics, and Newtonian principles—that help explain our reality. And then there are human laws, many of which cannot be scientifically proven and yet are clearly true.

The law of ketchup, for example: First there is nothing for a long time . . . then suddenly there is too much. Or physicist Douglas Hofstadter's law: Everything always takes longer than expected (even if you take Hofstadter's law into account). Or Parkinson's law: Meetings always take at least as twice long as we expect them to. Some of these truisms are world-famous; some well-kept secrets. Some are tongue-in-cheek; others imbue wisdom. But they all help us reframe our perspective and navigate the absurdities of everyday life. Rules of Thumb offers us the best of these laws for posterity.