“What doesn’t kill me makes me stronger.” Nietzsche was right, and Nasim Taleb’s book “Antifragile” explains why. Kids need thousands of hours of unsupervised play and thousands of conflicts and challenges that they resolve without adult help, in order to become independently functioning adults. But because of changes in American childrearing that began in the 1980s, and especially because of the helicopter parenting that took off in the 1990s for middle class and wealthy kids, they no longer get those experiences.Instead they are enmeshed in a “safety culture” that begins when they are young and that is now carried all the way through college. Books and words and visiting speakers are seen as “dangerous” and even as forms of “violence.” Trigger warnings and safe spaces are necessary to protect fragile young people from danger and violence. But such a culture is incompatible with political diversity, since many conservative ideas and speakers are labeled as threatening and banned from campus and the curriculum. Students who question the dominant political ethos are worn down by hostile reactions in the classroom. This is one of the core reasons why universities must choose one telos. Any institution that embraces safety culture cannot have the kind of viewpoint diversity that Mill advocated as essential in the search for truth.