Justice Louis Brandeis:
Those who won our independence . . . believed liberty to be the secret of happiness, and courage to be the secret of liberty. They believed that freedom to think as you will and to speak as you think are means indispensable to the discovery and spread of political truth; that, without free speech and assembly, discussion would be futile; that, with them, discussion affords ordinarily adequate protection against the dissemination of noxious doctrine; that the greatest menace to freedom is an inert people; that public discussion is a political duty, and that this should be a fundamental principle of the American government.