John Stuart Mill, On Freedom, 1859

John Stuart Mill

“The peculiar evil of silencing the expression of an opinion is that it is robbing the human race; posterity as well as the existing generation; those who dissent from the opinion, still more than those who hold it. If the opinion is right, they are deprived of the opportunity of exchanging error for truth: if wrong, they lose, what is almost as great a benefit, the clearer perception and livelier impression of truth, produced by its collision with error...  [E]very age [has] held many opinions which subsequent ages have deemed not only false but absurd; and... many opinions, now general, will be rejected by future ages.”

John Stuart Mill, On Freedom, 1859