The idea of intellectual freedom and a person's right to think and write whatever he wants is not a natural phenomenon in human history. It had to be developed and sustained by applying a lot of energy. So it is not so surprising that it collapsed once certain clear, bright lines began to be breached. We've witnessed the bridge point. ... When I arrived [at university in the 1960's] there was still an utter hegemony of the idea that the university is a sacred place where your obligation is to think and to write and you have freedom to do that. Once that ideal became contaminated with issues of social justice, the intellectual freedom principle quickly got lost. If it is not an absolute ideal, it is too obviously vulnerable to all sorts of emotional and very persuasive pleas, as in the 1960s. Intellectual freedom is a delicate plant.
Charles Murray Jan. 1995 - from "Forbidden Thoughts", a discussion published in American Enterprise by the American Enterprise Institute