The average Protestant persists in believing that the attitude of the Church towards the human intellect is adequately summed up in the phrase, familiar to us from childhood, "Open your mouth and shut your eyes." It is supposed that anybody who is brought up as a Catholic retains, without any further questioning or instruction on the point, the pious credulity with which he accepted all that his mother told him, all that the priest told him, when he was too young to think for himself. Any dawning doubts as to the sufficiency of such a motive for belief are crushed, we must suppose, with threats of hell and excommunication. This would be extraordinary enough, considering the number of Catholics there are in the world and the ample opportunities they have for being infected, in a world like ours, with the germs of unbelief. But, still more extraordinary, this Church, which has no proof of anything she says beyond her own bare assertion, is making converts, in an enlightened country like ours, at the rate of some twelve thousand in the year. How does she manage (one wonders) to play off her confidence trick with such repeated success?
This is, indeed, a phenomenon at which non-Catholics profess to feel the utmost astonishment. But it is a kind of astonishment which has grown blunted by usage; they have come to regard it as part of the order of things that their neighbours should become the victims, now and again, of this extraordinary tour de force. If they were compelled to picture to themselves the process of a conversion, they would, I suppose, conceive it something after this fashion--that the mind of the inquirer is hypnotised into acquiescence by the crafty blandishments of a designing priest; not by his arguments, for he has none, he only goes on shouting "Become a Catholic, or you will go to hell!"; not by his arguments, but by some fatal quality of fascination, which we breed, no doubt, in the seminaries. In a dazed condition, like that of the bird under the snake's eye, he assents to every formula presented to him, binds himself by every oath that is proposed to him, in one openmouthed act of unreasoning surrender. After that, of course, pride forbids him to admit, so long as life lasts, that the choice so made was a mistaken one; besides, one knows the power these priests have. Yes, it is very curious, the power attributed to these priests. When you have had the privilege of assisting at their education for seven years, you feel that "curious" is too weak a word for it.
--Msgr Ronald Knox, The Belief of Catholics, 1927