BOOM: Peter Berkowitz: An Open Letter to Swarthmore President Valerie Smith. “The creation of an environment hospitable to the exchange of opinions and the careful examination of rival analyses and assessments is a hallmark of liberal education. The promulgation of opinions and ideas insulated from critical examination, the stigmatizing and silencing of nonconformist voices, and the rallying of members of the campus community around a political cause are distinguishing features of indoctrination.”