David Horowitz can't seem to get into Saint Louis University no matter how hard he tries.

Six months ago, the university blocked a student organization from bringing Horowitz to the university for one of his talks about "Islamo-fascism." Horowitz is a conservative critic of higher education as well as a wide range of other sectors of society. The university said at the time that it didn't want Horowitz to talk on campus in a way that could be divisive (as many of Horowitz's critics have said his talks on Islam tend to be). Students also reported that they were told by university administrators that they didn't want Horowitz speaking without someone who would offer contrasting views.

Horowitz believes that the university is trying to keep him off campus no matter what -- and he's trying to call the university's bluff. Working with students at the university, he's now proposed a new topic for his appearance (academic freedom) and he's willing to appear with someone who will disagree with him in a debate (Cary Nelson, national president of the American Association of University Professors and a strong critic of Horowitz).

Again, however, the university is refusing to allow the event to take place. This time, according to an account posted by Horowitz on his Web site, the university is demanding that a third speaker be added to represent Roman Catholic values, given the university's religious ties. Horowitz says that this requirement for a Catholic perspective is hypocritical, given that the university holds many events that aren't from a Catholic perspective. He cited a recent program on "Living a Muslim Life in a Not-So-Muslim World."

A university spokesman declined repeatedly to discuss details of the institution's response to the proposed Horowitz-Nelson debate.

The spokesman said that the university was "not in direct discussions with Mr. Horowitz," but was talking to students and helping them "achieve their goals." Asked if the university was in fact telling the students that they could bring Horowitz and Nelson to campus only if they also had someone representing Catholic views, the spokesman said that "among other things, having a Catholic perspective was part of the discussion."

He also said: "Saint Louis University has a long history of encouraging a diversity of ideas, opinions and voices on its campus. Any suggestion to the contrary is simply not true."

In an interview, Nelson confirmed that he had agreed to appear with Horowitz. While Nelson has criticized many of Horowitz's views, he has defended his right to appear on campuses and criticized Saint Louis when it barred Horowitz last year.

Nelson believes that colleges should not force student groups who bring controversial speakers to campus to also bring someone with an opposing view, but he said he was fine appearing at Saint Louis University because Horowitz wanted to propose a debate format. He said the university was wrong to require yet another speaker to join them.

"I think what the university is now trying to do is not so much offensive as completely ludicrous," he said, saying that Saint Louis was acting "as if the keystone cops" were in charge of academic freedom.