Final answer:
The "clear and present danger" test permits the limitation of free speech under the First Amendment when such speech poses a direct threat to national security, like during wartime. Today, speech that incites imminent violence may be restricted, especially if it encourages actions against the government or its people.
Step-by-step explanation:
The "clear and present danger" test is a legal concept used to determine when speech can be limited under the First Amendment of the U.S. Constitution. This doctrine was established in the Schenck v. United States case, where Justice Holmes indicated that free speech could be restricted if it poses a clear and present danger to the security of the nation or its people. Specifically, it was ruled that Schenck's actions in distributing leaflets urging resistance to the draft during World War I were not protected by the First Amendment because they created such a danger during wartime.
An example of what might be considered a clear and present danger today could involve someone spreading detailed instructions on how to create a bomb during a period of increased terrorist threats. If the speech is deemed to incite imminent lawless action and is likely to produce such action, it may be restricted.
It's important to note that the Supreme Court has evolved in its interpretation of subversive speech. While abstract discussions about government overthrow are protected, incitements to imminent violent acts against the government can be limited. This distinction emphasizes the protection of speech unless it presents a direct and immediate threat to the nation's security.