Zealotry hostile to freedom of academic thought and speech has historically originated in a variety of sources: lay boards of trustees and administrators, the lay public, government, and, in the 1960s, students. The newest threat is from the group that academic freedom was designed to protect: the professoriat itself. As Professor Paul Walters observed in his 1986 presidential address to the AAUP:

The most dangerous threat to academic freedom... is that which comes from within the professoriate itself. For we bring to the academy our own deeply held political, religious, economic, and social convictions, convictions which make some of us rise in anger against colleagues whom we see as leftist, rightist, racist, sexist, atheistic, or anti-semitic. But insofar as we, educators and scholars, deny academic freedom to others, just as far do we sanction others who would deny it to us. 1