The morning hours sped past. From arithmetic, they turned to the English lesson. Next to perfection in her own Castilian, Josè felt that this language was most important for her. And she delighted in it, although her odd little pronunciations, and her vain attempts to manipulate words to conform to her own ideas of enunciation brought many a hearty laugh, in which she joined with enthusiasm. The afternoon, as was his plan for future work, was devoted to narratives of men and events, and to descriptions of places. It was a ceaseless wonder to Josè how her mind absorbed his instruction. "How readily you see these things, Carmen," he said, as he concluded the work for the day. "See them, Padre? But not with my outside eyes." The remark seemed to start a train of thought within her mentality. "Padre," she at length asked, "how do we see with our eyes?" "It is very simple, _chiquita_," Josè replied. "Here, let me draw a picture of an eye." He quickly sketched a rough outline of the human organ of sight. "Now," he began, "you know you cannot see in the dark, don't you?" "Yes, Padre?" "In order to see, we must have light." "What is light, Padre dear?" "Well--light is--is vibrations. That is, rapid movement." "What moves?" "A--a--a--well, nothing--that is, light is just vibrations. The pendulum of the old clock in Don Mario's store vibrates, you know--moves back and forth." "And light does that?" "Yes; light _is_ that. Now that chair there, for example, reflects light, just as a mirror does. It reflects vibrations. And these are all of just a certain length, for vibrations of just that length and moving up and down just so fast make light. The light enters the eye, like this," tracing the rays on his sketch. "It makes a little picture of the chair on the back of the eye, where the optic nerve is fastened. Now the light makes the little ends of this nerve vibrate, too--move very rapidly. And that movement is carried along the nerve to some place in the brain--to what we call the center of sight. And there we see the chair." The child studied the sketch long and seriously. "But, Padre, is the picture of the chair carried on the nerve to the brain?" "Oh, no, _chiquita_, only vibrations. It is as if the nerve moved just a little distance, but very, very fast, back and forth, or up and down." "And no picture is carried to the brain?" "No, there is just a vibration in the brain." "And that vibration makes us see the chair?" "Yes, little one." A moment of silence. Then-- "Padre dear, I don't believe it." "Why, _chiquita_!" "Well, Padre, what is it that sees the chair, anyway?" "The mind, dear." "Is the mind up there in the brain?" "Well--no, we can't say that it is." "Where is it, then?" "A--a--well, no place in particular--that is, it is right here all the time." "Well, then, when the mind wants to see the chair does it have to climb up into the brain and watch that little nerve wiggle?"