Freedom of expression is imperiled on today's college campuses. Citizens and educators alike are concerned about the number of shout-downs and disinvitations and their silencing effect on intellectual diversity. The use of speech codes, "safe spaces," new rules demanding "trigger warnings," and condemning "micro-aggressions" raises the specter of some new and unforeseen force in our history, where mere ideas are considered offensive and dangerous. In a fresh, analytically rich essay, "Campus Intolerance, Then & Now: The Influence of Marcusian Ideology," scholar Guenter Lewy examines the ways in which history is repeating itself and helps readers understand the philosophical underpinnings of today's campus difficulties. He explores in detail how "[w]hen today's students identify speech as violence and feel they can meet it with coercion, they are echoing Herbert Marcuse." The essay brings to light the effects of a philosophical ideology and, in so doing, empowers campus communities to address problems in more effective ways.