In his 1993 treatise “Medical Consequences of What Homosexuals Do,” Paul Cameron, the firebrand founder of the anti-gay Family Research Institute, revealed the “horror story” of “fecal sex.” Cameron claimed that “80 percent of gays” ingest “medically significant amounts of feces” on a regular basis, and also tend to “eat or wallow in it.” He and his allies – in other anti-gay groups and in legislatures across the country – can’t get enough of such descriptions, associating gay sex acts with feces, urine, blood, vomit, and other indelicacies that make for unpopular dinner-party discussion.

The lurid imaginings of Cameron and friends may seem a marginal oddity, just a small, eccentric fish paddling in the sea of propaganda that washes over Americans on a daily basis. But this fish has some mean fangs.

Disgust is a dangerous weapon. According to political philosopher Martha Nussbaum, we must understand its workings if we hope to comprehend how prejudice and discrimination have been hard-wired into this country’s legal system.