Human nature, at war for itself. For centuries, that was the fundamental view of our interior life: a perpetual struggle between the brain — the capital of rationality — and the heart, the sloppy seat of passion. A line from Ludacris' “Can't Live With You” voices this dilemma: “My mind says yes, but my heart says no” — a conundrum whose lyrical ancestry runs from Shakespeare to Coleridge (Samuel T.) to Cole (Porter).
But that vexing civil war, with its shifting fields of victory and surrender, has actually never been waged with such crisp skirmishing. Indeed, the fact that we can't trust our brains to be sober assessors, that they are as lacking in objective vigilance as the untrustworthy heart, that they were wired by an ancient (and often amoral) electrician and are thus no longer entirely useful in a modern age, has become reasonably well known to the general reader. Disciplines from neuroscience to behavioral psychology to evolutionary biology have created a new cranial transparency that's unleashed a gush of books like “Blink,” by Malcolm Gladwell; “Sway: The Irresistible Pull of Irrational Behavior,” by Ori Brafman and Ron Brafman; “Nudge: Improving Decisions About Health, Wealth and Happiness,” by Richard H. Thaler and Cass R. Sunstein; and “The Upside of Irrationality: The Unexpected Benefits of Defying Logic and Work and at Home,” by Dan Ariely.