Clear and present danger test
The "clear and present danger test" is a legal standard established by the U.S. Supreme Court to determine when speech can be limited under the First Amendment. Originating in the early 20th century, this test was articulated by Justice Oliver Wendell Holmes in the case of Schenck v. United States (1919). Holmes argued that the government could restrict speech if it posed a "clear and present danger" of inciting substantive evils that Congress has the right to prevent. Initially used to uphold convictions of antiwar activists during World War I, the test was later re-evaluated by Holmes and Justice Louis D. Brandeis, who emphasized the importance of protecting free speech, even during wartime.
As legal interpretations evolved, the clear and present danger test shifted from a tool for restricting speech to one that safeguards it. Notably, in Brandenburg v. Ohio (1969), the Supreme Court refined the test, asserting that advocacy of law violation could only be curtailed if it incited imminent lawless action. This modern interpretation significantly enhances protections for diverse and controversial speech, affirming the foundational principle that freedom of expression is essential in a democratic society.
Clear and present danger test
Description: First legal standard established by the Supreme Court in 1919 to determine whether speech posed such a direct and imminent threat to society that it could be punished without violating the free speech guarantees of the First Amendment to the U.S. Constitution.
Significance: Originally adopted to uphold the convictions of radicals during World War I, the clear and present danger test was transformed into a standard protecting a wide spectrum of controversial, offensive, and even hateful speech.
Although the First Amendment was ratified in 1791, thereby guaranteeing that Congress could make no law abridging freedom of speech, freedom of the press, or other personal rights, it was not until 1919 that the Supreme Court squarely addressed the limits of free speech.

Fearing the impact of disloyal speeches, leaflets, and newspaper articles during World War I, Congress passed the Espionage Act of 1917, which prohibited obstruction of the war effort. By 1919 three separate cases had reached the Court in which Eugene Debs, leader of the Socialist Party; Charles Schenck, an official of the Socialist Party; and Jacob Frohwerk, the publisher of a socialist newspaper, had all been convicted of violating the Espionage Act and sentenced to jail. In each case, the Court voted unanimously to uphold the convictions, despite arguments that the antiwar activists’ statements and publications were constitutionally protected under the First Amendment.
The task fell to Justice Oliver Wendell Holmes to write the opinions explaining the Court’s decisions. By 1919, Holmes, at age seventy-six, had served on the Court for seventeen years and had acquired a reputation as one of the finest legal minds in the country. In Schenck v. United States, Holmes wrote that the “question in every case is whether the words 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.” Without using the words “clear and present danger,” the companion opinions in Debs v. United States and Frohwerk v. United States, also written by Holmes, upheld the convictions.
A Reconsideration
In the coming months, however, Holmes and his friend and colleague, Justice Louis D. Brandeis, seriously reconsidered the importance of free speech in a democratic society, even in times of war. In Abrams v. United States (1919), while the majority of the Court upheld the convictions of a group of Russian immigrants for distributing pamphlets condemning President Woodrow Wilson for sending U.S. troops to fight against the Bolshevik Revolution in Russia, Holmes and Brandeis joined in a vigorous dissent.
Speaking for the Court, Justice John H. Clarke relied on Holmes’s own clear and present danger test. The leaflets violated the law because they had been distributed “at the supreme crisis of the war” and amounted to “an attempt to defeat the war plans of the Government.” Moreover, the general strike advocated by the Abrams defendants would have necessarily hampered prosecution of the war with Germany.
In dissent, Holmes did not repudiate his earlier opinions. Instead, he denied that “the surreptitious publishing of a silly leaflet by an unknown man” created “a clear and imminent danger that will bring about forthwith certain substantial evils that the United States constitutionally may seek to prevent.” Tilting the clear and present danger test away from an instrument in service of restricting speech and toward a shield protecting speech, Holmes argued that the First Amendment protected the expression of all opinions “unless they so imminently threatened immediate interference with the lawful and pressing purposes of the law that an immediate check is required to save the country.”
A Tool for Protection
The clear and present danger test fell out of favor until the late 1930’s when for more than a decade the Court used it to protect speech in a wide array of situations. However, in the midst of the Cold War and the mounting fear of communism, in Dennis v. United States (1951), the Court ignored the immediacy requirement of the clear and present danger test and upheld the convictions of eleven Communist Party leaders for conspiring to advocate the violent overthrow of the government.
In 1969 the Supreme Court adopted the Holmes-Brandeis dissent in Abrams. In Brandenburg v. Ohio, the Court reversed the conviction of a Ku Klux Klan leader under a state statute prohibiting criminal syndicalism. Consequently, a half century after it was first articulated, the clear and present danger test matured into a modern barrier to censorship, setting a high threshold protecting a wide spectrum of diverse and controversial speech. The Court held that the guarantees of the First Amendment “do not permit a State to forbid or proscribe advocacy of the use of force or of law violation except where such advocacy is directed to inciting or producing imminent lawless action and is likely to incite or produce such action.” In words reminiscent of Holmes’s prescient dissent in Abrams, the Court significantly strengthened constitutional protection for freedom of expression.