At a moment when the boundaries of freedom of speech are being debated, ex—New York Times columnist Anthony Lewis recaps America's love-hate relationship with the First Amendment in Freedom for the Thought That We Hate.

Has America always honored the First Amendment's guarantee of free speech?

Certainly not. The Sedition Act of 1798 made it a crime to publish rants against the president. Many editors and even a congressman were prosecuted.

When did an expansive reading of the First Amendment take hold?

The great moment was [Supreme Court Justice] Holmes's dissent in the 1919 Abrams case, [concerning] radicals who distributed pamphlets objecting to President Wilson's dispatch of troops to Russia after the Bolshevik revolution. Holmes's opinion—the first that viewed freedom of speech as a fundamental right—said that we have to respect even those opinions we believe to be “fraught with death.” The first cases that found a [Court] majority supporting free speech were in 1931.

Why did it take so long?

Most great First Amendment cases have been state, not federal, cases and it was only in 1925 that the Court applied the free speech guarantee to the states. Also, America often gets caught up in waves of fear and repression, as in World War I.

Speaking of a modern-day wave of fear, you write, “We should be able to punish speech that urges terrorist violence to an audience... whose members are ready to act.” How do you do that without censorship and repression?

I brought myself to [that sentence] with reluctance. The Court said in the 1969 Brandenburg case that you couldn't punish speech [that] urged violence or lawbreaking unless there would likely be an immediate response. Today, we know from bitter experience that people are ready to act immediately and violently; some were in the mosque that [shoe-bomber Richard] Reid attended.

In their uphill battle for First Amendment freedoms, were Holmes and Brandeis pioneers or just following the public consensus?

Both. Judges led the way; that's the point of my book. But they didn't do that in a vacuum. They did that with more and more Americans believing that free speech was a good thing. Still, [Holmes and Brandeis] were remarkably foresighted, and very lonely at the beginning. When Holmes wrote his Abrams dissent, members of the Court pleaded with him not to issue it. They said it would be unpatriotic [and] hurt the country; Holmes said he was sorry, but he wanted to do it. In that action, he very dramatically showed what free speech is all about: the right to say what he believed.