“To Douglas, the case turned on the purpose of the First Amendment. The judge had told the jury that in Chicago, it was unlawful to invite dispute. It followed that the conviction should be overturned. After all, he wrote, “a function of free speech under our system of government is to invite dispute. It may indeed best serve its high purpose when it induces a condition of unrest, creates dissatisfaction with conditions as they are, or even stirs people to anger. Speech is often provocative and challenging.”49”