"With our limited senses we are, in a way, merely peeping out of little slits in an armored conning-tower of life, out at the stupendous vibratory battles of the cosmos. Other creatures, in other planets, no doubt have other sense-organs to absorb other vibratory ranges. Their life-experiences are so different from ours that we could not possibly grasp them, any more than a blind man could understand a painting. "Nor could those creatures understand human life. We are safe in our own little corner of the universe, comfortably sheltered in our vestments of clay. And what we cannot understand, though it is all perfectly natural, we call religion, the supernatural, God." From a great vacancy, the Master's words proceeded. Leclair, tugging in vain at the bonds that, invisible yet strong as steel, held him powerless, stared with wild eyes. "There is no supernatural," said the now disembodied voice. "What we call spirit, psychic force, hypnosis, spiritualism, the fourth dimension, is really only life on another scale of vibration. If we could see the whole scale, we would recognize it as a vast, coherent, perfectly natural and rational whole, in which we human beings fill but a very insignificant part. That, monsieur, is absolutely true! "I have investigated, I have ventured along the coasts of the unknown vibratory sea, and even sailed out a little way on the waters of that unknown, mysterious ocean. Yet even I know nothing. What you are beholding now is simply a slightly new form of vibratory effect. The force that is holding you paralyzed on that chair is still another. A third, sent down the air-squadron. And--there are many more. "I am not really vanishing. That is but an illusion of your senses, unable to penetrate the screen surrounding me. I am still here, as materially as ever. Illusion, _mon cher monsieur_, yet to you very real!" The voice seemed moving about. The Frenchman now perceived something like a kind of moving blur in the cabin. It appeared a sort of hole of darkness, in the light; and yet the light shone through it, too. Every human eye has a blind spot in the retina. When things pass over this blind spot, they absolutely vanish; the other eye supplies the missing object. To the French ace it seemed that his eyes were all blind spots, so far as the Master was concerned. The effect of this vacancy moving about, shifting a chair, stirring a book, speaking to him like a spirit disembodied, its footfalls audible but its own self invisible, chilled the captive's blood. The Master said: "Now I have totally disappeared from your eye or any other material eye. I cannot even see myself! No doubt dwellers on some other planet would perceive me by some means we cannot imagine. Yet I am materially here. You feel my touch, now, on your shoulder. See, now I put out the lights; now I draw aside this curtain, and admit the golden morning radiance. You see that radiance, but you do not see me.