In any debate today about how to respond to “offensive” or “inflammatory” speech, it is only a matter of time before somebody trots out that most familiar of talking points. “There is no right,” the opiner will say, “to shout fire in a crowded theater!”

Taken from a 1919 Supreme Court decision by Justice Oliver Wendell Holmes, the fire-in-a-crowded-theater standard seldom gets much scrutiny. It tends to shut down discussion rather than to open it up. But that shouldn’t be—it is a flame well worth extinguishing.

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