You too have heard from some storyteller of a woman of surpassing beauty, beyond the Graces themselves or Heavenly Aphrodite; and, although you had not first asked whether he was telling the truth and whether this woman existed anywhere in the world, you fell in love with her at once, as they say Medea fell in love with Jason from a dream. But what above all brought you to this love—and has brought all who are in love with the same vision as you—was, I should guess, this: when he had told you about the woman and his first sketch had won your belief, he proceeded to fill in the details. You looked at nothing else, and so, when once you had let him get the first grip, he dragged you all by the nose and led you to the beloved by what he said was a straight path. The rest, I fancy, was easy: not one of you turned back to the entrance and enquired whether it was the true one and whether he had made a mistake and should not have entered; no, you followed in the steps of those who had made the journey before you, like sheep following their leader, although you should have considered at the entrance right at the beginning whether you ought to enter in there.

You will see better what I mean if you consider this analogy: suppose one of these daring poets were to say that there was once a man with three heads and six hands, and suppose that you facilely accepted this without asking if it were possible, just believing, he would at once follow it up by filling in the details appropriately—six eyes, six ears, three voices coming from three mouths, each taking food, and thirty fingers, unlike us with our ten on two hands; and, if he had to go to war, three hands held three shields—light, oblong, or round—, and three brandished axe, spear, and sword. Who would disbelieve these details now—details which are consistent with the first outline? It was there that you ought to have seen whether it was credible or acceptable thus. Once you admit the premises the rest comes flooding in; you will never stay its course, and disbelief is difficult now, for what follows is consistent in the way it follows the agreed premises. This has happened to you all. Because of your love and enthusiasm you made no enquiry into the conditions at each entrance. You go forward led by the consistency of what came after, not considering that things may be consistent and false. Suppose for instance you were to believe someone who said that twice five is seven and did not count for yourself, he will clearly go on to say that four times five is certainly fourteen, and so on, as long as he likes. This is what that marvellous geometry does—in the beginning it presents certain monstrous postulates and demands that we consent to them though they cannot exist—for instance points without parts, lines without breadth, and so on—and on these rotten foundations it erects its structure and claims to demonstrate truths, in spite of the fact that it starts from a false beginning.