Freedom of speech and the expression of controversial political viewpoints have been at the forefront on college campuses for a long while. Decade after decade, America has seen some of its finest moments and most horrific tragedies bubble up from movements that gained traction at universities before spreading into the nation’s consciousness.

Of course, this is old hat to anyone who lived through the 1960s, but on today’s campuses there are fewer people who witnessed it first-hand and a growing number who know only what they’ve read in history books or seen briefly in old news reels.

There are the iconic images of the four students gunned down at Kent State on May 4, 1970. But the tradition of campuses erupting in political strife goes much further back than that. The first such instance dates back to 1766, when Harvard University was beset by the Butter Rebellion. The protest was led by Asa Dunbar, grandfather of Henry David Thoreau, and was prompted when the university started serving rancid butter to students. Things got so tense that Harvard had to reach out to the Massachusetts governor to help stop the rebelling students.

Most recently, there have been instances across the country, and even here in Alabama at Auburn University, where there were attempts to stop controversial speakers from coming to campus because they espoused “hate speech” that marginalized large groups of people.

While the debate over who can say what on campus has focused oftentimes on First Amendment arguments, the center of attention is usually on either a student group or an outside speaker. But a new controversy has sprung up at Princeton University that centers entirely upon a professor who has been teaching there for four decades.

Professor Emeritus Lawrence Rosen, who is white, opened a course called “Cultural Freedoms: Hate Speech, Blasphemy and Pornography” by asking students a question. According to the Daily Princetonian, Rosen asked, “What is worse, a white man punching a black man, or a white man calling a black man a …” Rosen then used the racially-charged slur that many now substitute as the “N-word.” The student newspaper reported that Rosen went on to use the word several times. Though several students reportedly objected strongly, Rosen continued to use the word. Before the lecture was over, several students had walked out. One week later, the course has been cancelled.

A university spokesperson says Rosen chose to cancel the course and that Princeton did not pressure him. Princeton President Christopher L. Eisgruber and Carolyn Rouse, chairwoman of Princeton’s anthropology department, defended Rosen’s efforts to openly discuss what they acknowledged was a difficult word in order to provoke an emotional response from students and begin exploring what generated that reaction.

The incident has led campus leaders to begin discussing a wide range of topics that go well-beyond Rosen’s teaching methods. While the incident and ensuing uproar may be regrettable, the heated discussions that are now taking place are not. Words can be powerful and freedom often gets messy.