In 1998, President Bill Clinton’s confession that he had had an “inappropriate relationship” of a sexual nature with White House intern Monica Lewinsky started a national discussion about how a politician’s personal moral standards might affect his or her ability to lead. Clinton’s indiscretions also sparked public debate about sexual ethics in the United States. Some observers lament that Americans have largely abandoned conventional sexual values that discourage casual sex, premarital sex, promiscuity, and adultery. Leon Kass, a professor at the University of Chicago, maintains that the sexual revolution of the 1960s precipitated this decline in traditional sexual ethics. Central to the 1960s ideal of sexual liberation, Kass asserts, was the concept of separating sex from procreation, manifested in society’s endorsement of nonmarital sex and contraception. Numerous social changes...