I have chosen the subject of the slavery of the mind because I believe many worthy people imagine I am myself a slave. The nature of my supposed slavery I need not name and do not propose specially to discuss. It is shared by every sane man when he looks up a train in Bradshaw. That is, it consists in thinking a certain authority reliable; which is entirely reasonable. Indeed it would be rather difficult to travel in every train to find out where it went. It would be still more difficult to go to the destination in order to discover whether it was safe to begin the journey. Suppose a wild scare arose that Bradshaw was a conspiracy to produce railway accidents, a man might still believe the Guide to be a Guide and the scare to be only a scare; but he would know of the existence of the scare. What I mean by the slavery of the mind is that state in which men do not know of the alternative. It is something which clogs the imagination, like a drug or a mesmeric sleep, so that a person cannot possibly think of certain things at all. It is not the state in which he says, “I see what you mean; but I cannot think that because I sincerely think this” (which is simply rational): it is one in which he has never thought of the other view; and therefore does not even know that he has never thought of it. Though I am not discussing here my own religion, I think it only right to say that its authorities have never had this sort of narrowness. You may condemn their condemnations as oppressive; but not in this sense as obscurantist. St. Thomas Aquinas begins his enquiry by saying in effect, “Is there a God? It would seem not, for the following reasons”; and the most criticised of recent Encyclicals always stated a view before condemning it. The thing I mean is a man’s inability to state his opponent’s view; and often his inability even to state his own.

-The Thing (1929)