A professor at the University of Illinois, who taught courses on Catholicism in the school's religion department, has not been asked to return next semester. The instructor, Kenneth Howell, says the decision is a violation of his academic freedoms and claims the termination came after a student complained about an email he sent to students, in which he described homosexuality as a violation of "natural law."

According to The (Champaign, Ill.) News-Gazette, Howell wrote the email in preparation for an exam on natural law theory.

"Natural Moral Law says that Morality must be a response to REALITY," he wrote in the email, published by The News-Gazette. "In other words, sexual acts are only appropriate for people who are complementary, not the same."

Later in the email, Howell says society has disassociated sexuality and morality.

The student who complained about the professor's email took his concerns to the head of the university's religion department and other faculty. He called Howell's comments hate speech.

"Teaching a student about the tenets of a religion is one thing," the student wrote. "Declaring that homosexual acts violate the natural laws of man is another. The courses at this institution should be geared to contribute to the public discourse and promote independent thought; not limit one's worldview and ostracize people of a certain sexual orientation."

Howell has retained the services of the Alliance Defense Fund, an anti-LGBT legal defense organization based in Scottsdale, Ariz.