In class the other night I was talking about Emmett Till, and placed his murder in 1954. One of my students said she thought it was 1955, and I said something about how I thought it was ’54, but there was a chance I was wrong.

Someone quickly Googled, and confirmed that she was right. (I don’t know what I was thinking.) But before that happened, another student expressed shock that I had admitted the possibility that I might have been mistaken — in her experience, professors almost never did that. I said, “I’m a white guy teaching black history. If I insisted I was always right, I wouldn’t last five minutes.”

It’s a specific story with a larger point — there’s no surer way to turn potential allies against you than arrogance, and no quicker way to turn skeptics into friends than humility.