Nice New Yorker piece by Jill Lepore which starts with the Berkeley Free Speech movement of the 1960s and goes right up to the recent ‘kneeling’ protest by black NFL players. Concludes thus:

N.F.L. players insist that a stadium is a public square in which they have a right to exercise free speech. Their fight will rage on. But this fight began on college campuses, and it needs to be won there. All speech is not equal. Some things are true; some things are not. Figuring out how to tell the difference is the work of the university, which rests on a commitment to freedom of inquiry, an unflinching search for truth, and the fearless unmasking of error. But the university has obligations, too, to freedom of speech, whose premise, however idealized, is that, in a battle between truth and error, truth, in an open field, will always win. If the commitment to these difficult freedoms has sometimes flagged—and it has—it has just as often been renewed. Free speech is not a week or a place. It is a long and strenuous argument, as maddening as the past and as painful as the truth.