"This book explains the key principles of modern First Amendment law, showing that it embodies universal values and is eminently sensible; it lets government outlaw the most dangerous speech - speech that directly causes or threatens imminent harm, such as intentional incitement of imminent violence -- while outlawing the most dangerous censorship - restrictions on speech solely due to its unpopular or vaguely feared ideas. Before the modern Supreme Court adopted these speech-protective precepts - which are often summarized as the "emergency" and "viewpoint neutrality" principles - the government had discretion to restrict speech with an indirect, speculative connection to potential harm under the "bad tendency" test; it predictably wielded such discretion disproportionately to suppress its critics and advocates of human rights and social justice causes"--