Mark Vernon’s book, 42: Deep Thought on Life, the Universe, and Everything, is a collection of essayistic riffs spinning off from 42 different aphorisms. The book’s title is inspired, of course, by the supercomputer Deep Thought in The Hitchhiker’s Guide to the Galaxy, which comes up with the reply “42? as the answer to, well, everything. Vernon, a writer, broadcaster and journalist, draws his aphorisms from an eclectic range of reading:

The optimist proclaims that we live in the best of all possible worlds; and the pessimist fears this is true. —James Branch Cabell

They say travel broadens the mind; but you must have the mind. —G.K. Chesterton

Ask yourself whether you are happy and you cease to be so. —J.S. Mill

Vernon takes these words of wisdom and, through his essays, applies them to contemporary life, addressing issues like morality, politics and the environment. The result is a welcome combination of old and new. “The ancients loved aphorisms,” Vernon writes in the introduction. “They believed that although your real aim should be to fill your sails, reason, like a rudder, can steer you in the right direction. Socrates said that wisdom is not like water that can be poured from a jug into a basin. Life’s wisdom is manifest in habits and choices, passions and reflection.”