"[A] function of free speech under our system of government is to invite dispute. It may indeed best serve it's high purpose when it indices a condition of unrest, creates dissatisfaction with things as they are, or even stirs people to anger. Speech is often provocative and challenging. It may strike at prejudices and preconceptions and have profound unsettling effects as it presses for understanding."
in Free Speech and Political Protest [Marvin Summers], 1967