This essay is cited all over the pajama-sphere. Well worth reading. The excerpt is his closing passage, but the argument leading up to it is very well-crafted and insightful.
That’s why academic freedom is so important. It may not be written into the Bill of Rights—you know, the real one, the one in the Constitution. It is far younger than the rights enumerated there, and more fragile. But together with freedom of speech, freedom of religion, freedom of assembly, freedom of the press, freedom to petition the government for a redress of grievances, and the freedom of the people to be secure in their persons, houses, papers, and effects against unreasonable searches and seizures, academic freedom is an aspect of procedural liberalism that is one of the cornerstones of a free society. If you believe in the ideals of the open society and the intellectual legacies of the Enlightenment, you should believe in academic freedom—and you should believe that it is a freedom is worth defending.