"But then," I have pressed him, "why do you hesitate to speak of what you heard on that afternoon?" And once he answered me: "I glimpsed a finality," he said, "and that appalled me. Don't you see that ignorance is the means of our intellectual pleasure? It is the solving of the problem that brings enjoyment--the solved problem has no further interest. So when all is known, the stimulus for action ceases; when all is known there is quiescence, nothingness. Perfect knowledge implies the peace of death, implies the state of being one--our pleasures are derived from action, from differences, from heterogeneity. "Oh! pity the child," said Challis, "for whom there could be no mystery. Is not mystery the first and greatest joy of life? Beyond the gate there is unexplored mystery for us in our childhood. When that is explored, there are new and wonderful possibilities beyond the hills, then beyond the seas, beyond the known world, in the everyday chances and movements of the unknown life in which we are circumstanced. "Surely we should all perish through sheer inanity, or die desperately by suicide if no mystery remained in the world. Mystery takes a thousand beautiful shapes; it lurks even in the handiwork of man, in a stone god, or in some mighty, intricate machine, incomprehensibly deliberate and determined. The imagination endows the man-made thing with consciousness and powers, whether of reservation or aloofness; the similitude of meditation and profundity is wrought into stone. Is there not source for mystery to the uninstructed in the great machine registering the progress of its own achievement with each solemn, recurrent beat of its metal pulse? "Behind all these things is the wonder of the imagination that never approaches more nearly to the creation of a hitherto unknown image than when it thus hesitates on the verge of mystery. "There is yet so much, so very much cause for wondering speculation. Science gains ground so slowly. Slowly it has outlined, however vaguely, the uncertainties of our origin so far as this world is concerned, while the mystic has fought for his entrancing fairy tales one by one. "The mystic still holds his enthralling belief in the succession of peoples who have risen and died--the succeeding world-races, red, black, yellow, and white, which have in turn dominated this planet. Science with its hammer and chisel may lay bare evidence, may collate material, date man's appearance, call him the most recent of placental mammals, trace his superstitions and his first conceptions of a god from the elemental fears of the savage. But the mystic turns aside with an assumption of superior knowledge; he waves away objective evidence; he has a certainty impressed upon his mind.