Jacob Mchangama is a Danish lawyer, civil libertarian, human-rights advocate, and writer. He is the founder and director of Justitia, a think tank. He is an old friend of Jay’s, and a favorite of Jay’s. Mchangama’s new book is “Free Speech: A History from Socrates to Social Media.” Of the book, the late P.J. O’Rourke said, “The best history of free speech ever written and the best defense of free speech ever made.” With Jay, Mchangama goes over some basics, and some non-basics too.