WASHINGTON — When Ruth Bader Ginsburg went to work as a U.S. Supreme Court justice this month, capping a legal career spent, in part, fighting gender bias, one person who was overjoyed was the feminist legal theorist and anti-pornography crusader Catharine A. MacKinnon.

In many circles, MacKinnon is the better known of the two--a leading figure in the movement to rid the law of male bias, a popular professor, author and, lately, gossiped-about companion of Jeffrey Masson, the psychoanalyst suing Janet Malcolm of the New Yorker for libel.

At first glance, MacKinnon and Ginsburg appear to approach the problem of sexual inequality differently. As a lawyer, Ginsburg focused on issues of economics and status, such as equal pay. MacKinnon is preoccupied with pornography, rape and sexual abuse.

When MacKinnon developed her now famous anti-pornography ordinance in the 1980s, the American Civil Liberties Union accused her of promoting censorship. For years, Ginsburg worked for the ACLU, arguing many of its biggest sex-discrimination cases in the '70s, sometimes on behalf of men.

Yet, MacKinnon contends that their differences are largely generational. "Because she did what she did, I can do what I'm trying to do," the 47-year-old University of Michigan law professor said of the 60-year-old justice.

A Yale Law School graduate with a Ph.D. in political science, MacKinnon is credited with having persuaded the Supreme Court that sexual harassment is discrimination--not only when it involves a quid pro quo but also when the harasser simply creates a "hostile environment" for the victim.

In her new book, "Only Words," MacKinnon argues that equality and freedom-of-speech laws are "on a collision course." Pornography should be seen not as speech, she argues, but as an act of discrimination--something \o7 done to\f7 women and no more worthy of protection than a "Whites Only" sign.

The entire print run sold out before the publication date.

On leave from teaching, MacKinnon is spending the year in Europe on a fellowship, preparing a casebook on sex equality, pursuing litigation on behalf of Croatian and Bosnian victims of sexual atrocities and researching how pornography is produced worldwide.

Passing through Washington on a recent afternoon, she discussed Ginsburg's record as a lawyer and feminism's impact on the law.

Question: \o7 What was your reaction to Ruth Bader Ginsburg's nomination?\f7