Can otherwise constitutionally protected speech lose its protection because of the speaker’s supposedly improper purpose? The Supreme Court has sometimes said “no”—but sometimes it has endorsed tests (such as the incitement test) that do turn on a speaker’s purpose. Some lower courts have likewise rejected purpose tests. But others hold that, for instance, a purpose to annoy or distress can turn otherwise protected speech into criminal “harassment,” or that a selfish purpose can strip protection from otherwise protected government employee speech. This Article analyzes purpose tests in First Amendment law, and concludes that such tests are on balance unsound; the protection of speech should not turn on what a factfinder concludes about the speaker’s purposes.