The protracted study of pornography’s effect on women has led to a heated debate within the women’s movement between those who oppose pornography and those who defend it. According to writer Edward H. Hurley, the history of the feminist response to pornography can be divided up into three “waves.”

During the first wave of the feminist critique of pornography, which began in the early 1970s, feminists such as Gloria Steinem viewed pornography as a means of objectifying women and sex. Others, such as Helen Longini, stressed that pornography degraded women. First wave feminists claimed that pornography—as opposed to erotica—portrayed women in a demeaning way.

In the 1970s, however, this mainstream feminist stance gave way to the more radical view that pornography subordinated women and therefore enforced gender inequality. Radical...