"CONGRESS SHALL MAKE no law . . . abridging the freedom of speech." These words in the First Amendment to the Constitution are at issue when the government seeks to limit individual expression, whether that expression takes the form of words (political advocacy, racial slurs, song lyrics) or expressive conduct (wearing a peace symbol or swastika, burning a cross, trampling an American flag). The paradox that often underlies free speech conflicts is that the more the majority may object to certain speech, the more that speech may require, and even deserve, First Amendment protection. At the same time, the more protection given to words and actions under the First Amendment, the more society may be exposed to potential harm and risky choices.

The marketplace of ideas

Some wonder why speech, particularly speech that most people find objectionable and that may promote...