The self-cannibalization of Europe

Unlimited tolerance must lead to the disappearance of tolerance. If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them.

Karl Popper, “On the Paradox of Tolerance,” in The Open Society and Its Enemies, 1945