This discipline recognises a knowledge of the enemy's case as beneficial to the teachers, but finds means, consistent with this, of denying it to the rest of the world: thus giving to the elite more mental culture, though not more mental freedom, than it allows to the mass. By this device it  succeeds in obtaining the kind of mental superiority which its purposes require; for though culture without freedom never made a large and liberal mind, it can make a clever nisi prius advocate of a cause. But in countries professing Protestantism, this resource is denied; since Protestants hold, at least in theory, that the responsibility for the choice of a religion must be borne by each for himself, and cannot be thrown off upon teachers. Besides, in the present state of the world, it is practically impossible that writings which are read by the instructed can be kept from the uninstructed. If the teachers of mankind are to be cognisant of all that they ought to know, everything must be free to be written and published without restraint.

On Liberty, by John Stuart Mill (1859)