the heart of love.4 No wonder we think it’s all we need for marriage. Of course, as social scientists—no, strike that—as people who have simply been married for a few years, we all know that love, the kind that lasts, is far more than a heart-skips-a-beat sensation. Yet still this notion persists for far too many good-intentioned couples—even experienced couples who are marrying for the second or third time.5 In case you’re wondering, we have nothing against romance. We resonate with philosophical