Writing for a unanimous Court, Justice Oliver Wendell Holmes established the clear and present danger test, a crucial standard for evaluating restrictions on free speech. Holmes wrote, “The question in every case is whether the words used are used in such circumstances and are of such a nature as to create a clear and present danger that they will bring about the substantive evils that Congress has a right to prevent.” This standard essentially meant that speech could be restricted if it posed a direct and immediate threat to public safety or order. Holmes further elaborated on this principle, explaining that “[t]he most stringent protection of free speech would not protect a man in falsely shouting fire in a theatre and causing a panic.”

Holmes also distinguished between the intent and effect of Schenck's speech, arguing that while the pamphlets may not have directly incited violence, their potential to disrupt military recruitment and undermine the war effort constituted a clear and present danger. He noted, “[w]e admit that in many places and in ordinary times the defendants in saying all that was said in the circular would have been within their constitutional rights. . . but the character of every act depends upon the circumstances in which it is done.” Holmes acknowledged the importance of context in evaluating free speech claims and recognized that the government's power to restrict speech was broader during wartime, given the heightened need for national security and order.

While acknowledging the importance of protecting freedom of speech, Holmes stated that “[w]hen a nation is at war many things that might be said in time of peace are such a hindrance to its effort that their utterance will not be endured.” Holmes ultimately concluded that free speech protections were not absolute and must be balanced with the government's duty to maintain order and security, particularly during wartime.