Two Penn State professors made the list of the nation's most dangerous academics of higher education, according to conservative author David Horowitz in his book, The Professors: 101 Most Dangerous Academics in America.

The book hit shelves on Feb. 13 and includes sections devoted to revealing the dangers of senior lecturer in sociology Sam Richards and professor of English Michael Berubé.

Horowitz said when he was in school, his professors never singled him out for his beliefs and he never heard them express their political views. He said this book is part of his fight to restore that respect.

"I have no problem with professors being left-wing. The problem is if they bring political agendas to the classroom," Horowitz said. "Advocacy is a form of preaching -- not teaching."

Among other things in the book, Horowitz accused Richards of teaching courses "in such fashionably Marxist-cum-post-modernist programs as 'cultural studies,' " and quoted him as saying that he is open about bringing his own ideology to the classroom.

He criticized him for giving his students credit to attend liberal events and said he has never been trained in the field he teaches.

"Sam Richards is an amateur academic ... you might as well go to the guy on the street and say, 'Hey, what

do you think about race relations?' " Horowitz said. "If Penn State were renamed the University of Marxism, I'd say no problem."

Richards said Horowitz attained content from his Web site and not class lectures.

"Horowitz has absolutely no idea what I do in my classroom," he said. "I haven't invoked the name Marx in a classroom in probably 12 years."

Richards said that while he agrees there may be a liberal bias in higher education, he feels that young people in general tend to be more liberal.

"I think this conversation we're having about liberal bias in the universities is an important conversation that we should have. It's just unfortunate for the conservatives that Horowitz is the one waving the flag for their cause because he's such a knucklehead," he said.

Richards said he gives students credit for attending both liberal and conservative events, including seeing Horowitz speak, and urges them to attend events that showcase views opposing their own to challenge individual beliefs.

Anterria Walker, who is one of Richards' teaching assistants for Sociology 119 (Race and Ethnic Relations), said Richards presents different sides of controversial issues.

"It's apparent what his opinion is, but he allows everybody to express their opinions, too," she said.

Berubé's teaching methods were also questioned in the book, which states, "The idea that a university might be an institution dedicated to the pursuit of knowledge rather than the imposition of left-wing fashions would seem to professors like Michael Berubé an idea from a galaxy far away."

Berubé disagreed.

"I feel I got in [the book] on a technicality because I've been mocking [Horowitz] mercilessly over the last year," Berubé said, referring to the numerous debates he has had with Horowitz and his magazine, FrontPage. "I'm in the least important category -- people who bother him to no end."

Berubé said the book has more to do with politics than education.

"It's a political campaign against liberals in academia," he said, calling Horowitz's claims "one string of nonsense after another" and "layers and layers of lunacy."

Berubé also said that much of the book attributes essays or quotations incorrectly.

Horowitz said his process for fact checking involves researching the topic, publishing it and then printing corrections if errors are pointed out. He added that no errors have been pointed out in the book.

Horowitz's publicist, Patricia Jackson, said Regnery Publishing, Inc. makes sure "the source was cited correctly and accurately tagged to where it appears in the books," but could not comment on claims like Berubé's.

"We don't normally specifically fact check," she said.