The man was at a loss for an answer. Carmen suddenly crumpled the sketch in her small hand and smiled up at him. "Padre dear, I don't believe our outside eyes see anything. We just think they do, don't we?" Josè looked out through the open door. Carmen's weird heron was stalking in immense dignity past the house. "I think Cantar-las-horas is getting ready to sing the Vespers, _chiquita_. And so Doña Maria probably needs you now. We will talk more about the eye to-morrow." By the light of his sputtering candle that night Josè sat with elbows propped on the table, his head clasped in his hands, and a sketch of the human eye before him. In his confident attempt to explain to Carmen the process of cognition he had been completely baffled. Certainly, light coming from an object enters the eye and casts a picture upon the retina. He had often seen the photographic camera exhibit the same phenomenon. The law of the impenetrability of matter had to be set aside, of course--or else light must be pure vibration, without a material vibrating concomitant. Then, too, it was plain that the light in some way communicated its vibration to the little projecting ends of the optic nerve, which lie spread out over the rear inner surface of the eye. And equally patent that this vibration is in some way taken up by the optic nerve and transmitted to the center of sight in the brain. But after that--what? He laughed again at Carmen's pertinent question about the mind climbing up into the brain to see the vibrating nerve. But was it so silly a presumption, after all? Is the mind within the brain, awaiting in Stygian darkness the advent of the vibrations which shall give it pictures of the outside world? Or is the mind outside of the brain, but still slavishly forced to look at these vibrations of the optic nerve and then translate them into terms of things without? What could a vibrating nerve suggest to a well-ordered mind, anyway? He might as logically wave a piece of meat and expect thereby to see a world! He laughed aloud at the thought. Why does not the foolish mind leave the brain and look at the picture on the retina? Or why does it not throw off its shackles and look directly at the object to be cognized, instead of submitting to dependence upon so frail a thing as fleshly eyes and nerves? As he mused and sketched, unmindful of the voracious mosquitoes or the blundering moths that momentarily threatened his light, it dawned slowly upon him that the mind's awareness of material objects could not possibly depend upon the vibrations of pieces of nerve tissue, so minute as to be almost invisible to the unaided sight. Still more absurd did it appear to him that his own mind, of which he might justly boast tremendous powers, could be prostituted to such a degree that its knowledge of things must be served to it on waving pieces of flesh.