The most stringent protection of free speech would not protect a man falsely shouting fire in a theatre and causing a panic... 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.

Snowden, Ethel. "Women and War." Journal of Proceedings and Addresses of the National Education Association. 1915.

Taney, Roger B. United States, Supreme Court. Dred Scott v. Sandford. United States Reports, vol. 60, 6 Mar. 1857, pp. 393-633. Justia, supreme.justia.com/cases/federal/us/60/393/.

Luxemburg, Rosa. "The Russian Revolution." The Russian Revolution and Leninism or Marxism? Trans. Bertram Wolfe. University of Michigan Press, 1961, ch. 6. Originally, Die russische Revolution [The Russian Revolution]. Paul Levi, 1922, ch. 6.