Hysteria doesn’t care about the facts. In an extraordinary feat, Black Lives Matter protestors took something that didn’t happen from a case of justifiable use of police force in Ferguson, Mo., and made it the slogan — “hands up, don’t shoot” — of a movement alleging systemic police racism. The truth of Ferguson didn’t matter so much as the myth of Ferguson, into which could be poured great urgency and moral fervor.

Hysteria will believe anything. After the San Bernardino attack, the media hawked the bogus statistic that there had been more than 350 mass shootings this year, which would mean the country is a veritable daily shooting gallery for lunatics and fanatics. Mass shootings are horrific and they understandably dominate the news when they happen, but who could believe this number? A more careful measure at Mother Jones tallied four mass shootings in 2015.

Hysteria can be a powerful organizing tool. The entire world got together in Paris to sign on to a climate accord, based on the pretense that without immediate action the Earth will be rendered all but uninhabitable by the ravages of climate change.

Hysteria is a weapon. On college campuses, student didn’t just seek safe spaces from speech they deemed uncongenial and decry inadvertent slights known as micro-aggressions. They terrorized anyone not with the program.