"Freedom of expression is the well-spring of our civilization... The history of civilization is in considerable measure the displacement of error which once held sway as official truth by beliefs which in turn have yielded to other truths. Therefore the liberty of man to search for truth ought not to be fettered, no matter what orthodoxies he may challenge."

Previous Quote

A function of free speech under our system of government is to invite dispute. It may indeed best serve its high purpose when it invites a condition of unrest, creates dissatisfaction with conditions 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 passes for acceptance of an idea.

— William O. Douglas