Thomas Sowell‘s latest column at Human Events depicts disappointing developments within the modern academic world.

Ironically, despite the victory of democracy over dictatorship that brought the Cold War to an end, within American society there has slowly but steadily developed in too many of our own colleges and universities a set of restrictions on what can be said on campus, either by students or professors, or by outside speakers with views that contradict the political correctness of our time.

There is no barbed wire around our campuses, nor armed guards keeping unwelcome ideas out. So there is no “iron curtain.” But there is a curtain, and it has its effect.

One effect is that many of the rising generation can go from elementary school through postgraduate education at our leading colleges and universities without ever hearing a coherent presentation of a vision of the world that is fundamentally different from that of the political left.

There are world class scholars who are unlikely to become professors at either elite or non-elite academic institutions because they do not march in the lockstep of the left. Some have been shouted down or even physically assaulted when they tried to give a speech that challenged the prevailing political correctness.

Harvard is just one of the prestigious institutions where such things have happened — and where preemptive surrender to mob rule has been justified by a dean saying that it was too costly to provide security for many outside speakers who would set off campus turmoil.

Despite the fervor with which demographic “diversity” is proclaimed as a prime virtue — without a speck of evidence as to its supposed benefits — diversity of ideas gets no such respect.