How is a false statement of fact different from an opinion in defamation law?

In defamation law, the distinction between a false statement of fact and an opinion is fundamental to protecting free speech. Under the First Amendment, while factual falsehoods can be subject to legal action, the expression of an opinion is generally protected and cannot be punished, even if that opinion is considered morally wrong.1

The key differences are:

• Objective Verifiability: A statement is considered a fact if it can be objectively proven true or false. Conversely, statements that cannot be objectively verified—such as "I think Bill is a jerk"—are classified as opinions and are not defamatory.2
• Implied Facts: An opinion can cross the line into defamation if it implies the existence of an underlying false fact that could damage a person's reputation. For example, stating "I think Bill embezzles money" implies a specific, injurious act that could be proven false.2
• Legal Context: As established in New York Times Co. v. Sullivan, the law protects robust public debate. For public officials to succeed in a libel suit, they must prove "actual malice," meaning the statement was made with knowledge of its falsity or reckless disregard for the truth.234