Berkeley, Calif.

LIFE, I found myself thinking as a line of Alameda County deputy sheriffs in Darth Vader riot gear formed a cordon in front of me on a recent night on the campus of the University of California, Berkeley, is full of strange contingencies. The deputy sheriffs, all white men, except for one young woman, perhaps Filipino, who was trying to look severe but looked terrified, had black truncheons in their gloved hands that reporters later called batons and that were known, in the movies of my childhood, as billy clubs.

The first contingency that came to mind was the quick spread of the Occupy movement. The idea of occupying public space was so appealing that people in almost every large city in the country had begun to stake them out, including students at Berkeley, who, on that November night, occupied the public space in front of Sproul Hall, a gray granite Beaux-Arts edifice that houses the registrar’s offices and, in the basement, the campus police department.

It is also the place where students almost 50 years ago touched off the Free Speech Movement, which transformed the life of American universities by guaranteeing students freedom of speech and self-governance. The steps are named for Mario Savio, the eloquent undergraduate student who was the symbolic face of the movement. There is even a Free Speech Movement Cafe on campus where some of Mr. Savio’s words are prominently displayed: “There is a time ... when the operation of the machine becomes so odious, makes you so sick at heart, that you can’t take part. You can’t even passively take part.”

Earlier that day a colleague had written to say that the campus police had moved in to take down the Occupy tents and that students had been “beaten viciously.” I didn’t believe it. In broad daylight? And without provocation? So when we heard that the police had returned, my wife, Brenda Hillman, and I hurried to the campus. I wanted to see what was going to happen and how the police behaved, and how the students behaved. If there was trouble, we wanted to be there to do what we could to protect the students.