Derek Bok, former president of Harvard University, writes:  Last month the presidents of Harvard, Penn, and MIT were summoned to appear before a congressional committee. For five hours, they were subjected to withering interrogation about the response of their universities to the harassment and intimidation of Jewish students following the massacre of 1,200 people in Israel and the subsequent invasion of Gaza. In response to repeated questions about how their universities would deal with students calling for “intifada” or chanting “from the river to the sea,” the answers the presidents gave in seeking to explain the intricacies of the First Amendment provoked an angry response from several members of the committee for being too legalistic and even calls by a few for the presidents to resign.