"True! But I should not be at all surprised, when I take you there, if you claim that it is the counterpart of your dream."
"Why do you think that, Doctor, when you have just said truly, that such a fact would be impossible?"
"It would be impossible that such a thing should be a fact, but it is not at all impossible that you should think it to be a fact. Let me explain myself more clearly. As I said before, one cannot produce in the mind an absolutely accurate image of a thing which he has never seen. But mental images may be created, not alone through the sense of sight, but also through the sense of hearing. Last night I told you the story of Æsculapius. I described to you the teocali which had been reared in his memory. I told you that at the very top a dome-like chamber was specially dedicated to Æsculapius. I also explained to you that in the dome which I have discovered the walls are covered with hieroglyphical sculpturing. With such a description of the place, meagre as it is, you could readily construct a mental image, which would be sufficiently like the original for you to believe it identical. A dome is a dome, and, in regard to hieroglyphical figures, in the books in my library you have seen many pictures of those found on this continent."
"Still, Doctor, that would only enable me to create an image which would be similar. It could not be identical."
"No! It could not be identical. But suppose that you enter the crypt! Instantly you look about you, and an image of the place is imprinted upon your brain. This is objectively produced. You compare it with the subjective image left by your dream, and you are astonished at the similarity. Note the word! You look around you again, and again an objective image is formed. Again you essay a comparison: but what happens now? As clearly fixed upon your brain as you believe your dream to be, it is but a shadowy impression compared to those which come to you when awake. So your subjective image of the place is readily displaced by that first objective impression, and when you compare the second, it is with this, and not with your dream at all. As both are identical, you form the conclusion that your dream and the actuality are identical. So your first idea that they are similar passes, and you adopt the erroneous belief that they are identical. You have compared two objective impressions, where you believe that one was the subjective image of your dream. Thus you are deceived into believing that a miracle has occurred. And thus have all miracles been accepted as such; thus have all superstitions been created, through the incorrect appreciation of events and their causes."
"I see what you mean, Doctor, and I recognize, now, how easy it is to fall into error. Few in this world have the analytical instinct possessed by yourself. Yet, I must confess, I am anxious for the test to-night. Now that you have warned me, I wish to see whether my first comparison will give me the idea that the two images are identical, or merely similar."
From this speech Dr. Medjora saw that the lad was not entirely convinced. He concluded therefore to risk a test, that would definitely settle the question.
"Leon," said he, "you are a good draughtsman. Draw for me a picture of any part of the hieroglyphical sculpture which is most distinct in your recollection!"
In this the Doctor depended upon the fact that Leon could have but an indistinct remembrance of the place itself, because, from the moment of his awakening in the crypt, his mind had been confused by the rapid series of surprises presented to his eyes. The revolving lamps, and the glare emitted by them, would have been sufficient to create such shadows, that the sculptured figures would have been distorted, the mind itself being too much occupied for more than a very cursory glance at the walls of the place. Leon, however, at once began to draw, and within a few minutes he handed the paper to the Doctor, who was pleased to find upon it a poor copy of some figures in Kingsborough's Antiquities. Thus the Doctor's speculation was vindicated, because as soon as Leon had endeavored to draw, he copied an image in his mind, made by a picture which he had had time to study closely, yet which in his thought replaced the indistinct impression obtained in the crypt.
"You are quite sure, Leon," asked the Doctor, "that this is a figure which you saw in your dream."