What’s bad for your nervous system, in contrast, are long stretches of simmering stress. If you spend a lot of time in a harsh environment worrying about your safety, that’s the kind of stress that brings on illness and remodels your brain. That’s also true of a political climate in which groups of people endlessly hurl hateful words at one another, and of rampant bullying in school or on social media. A culture of constant, casual brutality is toxic to the body, and we suffer for it.

That’s why it’s reasonable, scientifically speaking, not to allow a provocateur and hatemonger like Milo Yiannopoulos to speak at your school. He is part of something noxious, a campaign of abuse. There is nothing to be gained from debating him, for debate is not what he is offering.