Let us now consider whether justice requires the toleration of the intolerant, and if so under what conditions. There are a variety of situations in which this question arises. Some political parties in democratic states hold doctrines that commit them to suppress the constitutional liberties whenever they have the power. Again, there are those who reject intellectual freedom but who nevertheless hold positions in the university. It may appear that toleration in these cases is inconsistent with the principles of justice, or at any rate not required by them.

p. 216 - A Theory of Justice (1971; 1975; 1999)