Gabriel Arana says opponents of gay rights have long relied on disgust to justify discrimination, but recent legal gains suggest this argument is losing its potency. The most incendiary evidence presented in court last January in the effort to overturn California's Proposition 8 -- the ban on same-sex unions adopted by the state's voters in 2008 -- dealt with whether prejudice had motivated the ban's advocates. Video footage and documents from the "Yes on 8" campaign showed its organizers claiming, for example, that gays are 12 times more likely than straight people to molest children and that the "homosexual agenda" includes legalizing pedophilia. If gay marriage were allowed to continue in California, one "Yes on 8" organizer wrote, "every child, when growing up, would fantasize [about] marrying someone of the same sex." And if the measure did not pass, he warned, the states would fall "one by one into the hands of Satan." In a simulcast rally, campaigners compared gay marriage to September 11. To many Americans, it seems bizarre to think of gay marriage as a threat comparable to terrorism. Those who have gay friends see them pursuing fulfillment in familiar ways: raising healthy children, working, and living beside us. Nonetheless, Proposition 8's campaigners seem to have tapped into a feeling shared by enough California voters to get the measure passed. In her new book, From Disgust to Humanity, University of Chicago philosopher Martha Nussbaum argues that visceral appeals to disgust -- as opposed to rational principles -- lie at the heart of contemporary laws targeting gay people, particularly gay men. Some philosophers and ethicists have defended the use of disgust as a moral barometer, but Nussbaum contends that such an approach is incompatible with the goals of a fair and equitable society. What may be surprising to some is that laws targeting gays and lesbians are, in historical terms, fairly recent. Although Anglo-American legal tradition has long included laws against sodomy, these prohibitions were part of general bans on non-procreative sexual activity; it was only in the late 19th century that specific laws were enacted targeting "homosexual acts." Nussbaum hazards that the shift is related to Victorian morality, but a more compelling explanation is that laws targeting gays and lesbians came about simultaneously with the emergence of the homosexual as a social identity in the 19th century. A distinct identity and targeted repression came together. KEEP READING. . .