Why have kings, emperors, and governments killed and imprisoned people to shut them up? And why have countless people risked death and imprisonment to express their beliefs? What role has free speech played in the struggles for the values that define the aspirations of modern democracies:  Full suffrage, equality of the sexes and the emancipation and empowerment of minorities. In his new podcast “Clear and Present Danger: A History of Free Speech”, Columbia Global Freedom of Expression Visiting Scholar Jacob Mchangama explores the history of free speech from the trial of Socrates to the Great Firewall. Go to www.freespeechhistory.com for more details