"The history of intellectual growth and discovery clearly demonstrates the need for unfettered freedom, the right to think the unthinkable, discuss the unmentionable, and challenge the unchallengeable." (1974) @Yale HT @Rosalind_Arden_ https://yalecollege.yale.edu/get-know-yale-college/office-dean/reports/report-committee-freedom-expression-yale#Report_of_the_Committee

"We value freedom of expression…because it provides a forum for the new, the provocative, the disturbing, and the unorthodox. Free speech is a barrier to the tyranny of authoritarian or even majority opinion as to the rightness or wrongness of particular doctrines or thoughts."

Also quite right to point out that commitment to free speech, like everything else, is a hypothesis:

"We take a chance…when we commit ourselves to the idea that the results of free expression are to the general benefit in the long run, however unpleasant they may appear at the time. The validity of such a belief cannot be demonstrated conclusively."