Paul Moon gets to the nub of the need for free speech:
. . . One of the reasons is that free speech is too often (and mistakenly) depicted as an end in itself. “It is our right,” is a common claim, as though that alone clinches the argument. What is missed in the ensuing sound and fury of people demanding either their free speech rights, or protection from unrestrained speech is the fact that for centuries, free speech was advanced not as a right to be attained for its own sake, but as a means of achieving something immeasurably more important: the truth.
Free speech is a right, but not an end, it’s a path to truth..
Perhaps the most insightful observation on this aspect of free speech is attributed to the Czech theologian Jan Hus (1369-1415). He urged humanity to “love the truth, let others have their truth, and the truth will prevail.” This succinct adage specifies the truth as the basis for free speech, the importance of allowing others to have divergent opinions, and the possibility that a consensus will ultimately be achieved. Is it idealistic? Of course it is. But the alternative, in which there is no tolerance for diverse views, and no greater purpose for speech, other than its own uttering, is an immeasurably worse approach. . .
Letting people air diverse views provides an opportunity to examine and debate them; to question and challenge; to prove and disprove.
. . The freedom to try to discover the truth was a burning issue (sometimes literally) in previous centuries, and yet in our more enlightened age, the emphasis on seeking truth seems to have been nearly extinguished. Promoting free speech as a right to insult, or conversely, censoring it for some perceived protective purpose, misses the point.
If free speech is to be defended, it ought to be primarily because it is the best means we have of attaining the truth, and those truths may indeed eventually make us free. . .
Censorship and bans might stop people airing their views publicly but they won’t change them.
Only when people are free to speak and speak freely, is there the opportunity to validate and verify, ridicule and repudiate, expose the lies and find the truth.