Ever since Adam and Eve ate the apple, Ulysses had himself tied to the mast, the grasshopper sang while the ant stored food and St. Augustine prayed “Lord make me chaste — but not yet,” individuals have struggled with self-control. In today’s world this virtue is all the more vital, because now that we have largely tamed the scourges of nature, most of our troubles are self-inflicted. We eat, drink, smoke and gamble too much, max out our credit cards, fall into dangerous liaisons and become addicted to heroin, cocaine and e-mail.