I, like Lawrence H. Summers, am concerned about antisemitism on college campuses. Mr. Summers wrote in his Nov. 16 Thursday Opinion column, “Why are universities confused about antisemitism?,” that we can address it with timely statements. But edicts cannot change culture.

Culture change on college campuses is a contact sport. If you aren’t on the ground, engaging with the campus community regularly, you cannot change the culture. College students don’t care about some statement from someone they never met. Changing culture is hard; it means tough conversations over a sustained period of time. It requires building a community of trust so that people know you care about them, that you are not there to offer moral sermons via email and social media.