What did Justice William Brennan mean by describing public debate as “uninhibited, robust, and wide-open”?

In the landmark case New York Times Co. v. Sullivan, Justice William Brennan used the phrase “uninhibited, robust, and wide-open” to characterize the nature of public debate essential to a democracy.1

By this, Brennan meant that in order to ensure a full and meaningful discussion on important public issues, the First Amendment must protect all opinions, including those that are unpleasant or expressed in an unpleasant manner. This standard was established to prevent libel laws from being used to silence critics of government officials.1

Consequently, the court ruled that for a public official to succeed in a defamation suit, they must prove “actual malice”—meaning the statement was made with knowledge of its falsity or with reckless disregard for the truth. This decision effectively constitutionalized defamation law, ensuring that minor factual errors made in good faith do not stifle the freedom of speech and the press.1