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.
John Stuart MillThe struggle between Liberty and Authority is the most conspicuous feature in the portions of history with which we are earliest familiar; particularly in that of Greece, Rome, and England
John Stuart MillBad men need nothing more to compass their ends, than that good men should look on and do nothing.
John Stuart MillEven if the received opinion be not only true, but the whole truth; unless it is suffered to be, and actually is, vigorously and earnestly contested, it will, by most of those who receive it, be held in the manner of a prejudice, with little comprehension or feeling of its rational grounds
John Stuart Mill