Benjamin Franklin was in his early twenties when he embarked on a "bold and arduous project of arriving at moral perfection," intending to master the virtues of temperance, silence, order, resolution, frugality, industry, sincerity, justice, moderation, cleanliness, tranquility, chastity, and humility. He soon gave up on perfection but continued to believe that these virtues, coupled with a generous heart and a bemused acceptance of human frailty,...