On Liberty by John Stuart Mill Chapter 2 Page 66

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 cognizant of all that they ought to know, everything must be free to be written and published without restraint.

If, however, the mischievous operation of the absence of free discussion, when the received opinions are true, were confined to leaving men ignorant of the grounds of those opinions, it might be thought that this, if an intellectual, is no moral evil, and does not affect the worth of the opinions, regarded in their influence on the character.

The fact, however, is, that not only the grounds of the opinion are forgotten in the