sensation, and learns to bring those together and thereby is manufacturing in its consciousness the conception of the ego, personal, individual existence, another great metaphysical notion. Descartes has said—Cogito, ergo sum—I think, therefore I am. The baby, if he had written in Descartes's place, would have said—"I feel, therefore I am." The first five months constitute the first period of the baby's development. Its powers are formed, and the foundations of knowledge have been laid. The second period is a period of amazing research, constant, uninterrupted, untiring; renewed the instant the baby wakes up, and kept up until sleep again overtakes it. In the six months' baby we find already the notion of cause and effect. You see he is dealing mostly in metaphysical things, getting the fundamental concepts. That there is such an idea as cause and effect in the baby's mind is clearly shown by the progress of its adaptive intelligence. It evidently has now distinct purposes of its own. It shows clearly at this age also another thing which plays a constant and important rôle in our daily life. It has the consciousness of the possibilities of human intercourse; it wants human companionship. And with that the baby's equipment to start upon life is pretty well established. It has discovered the material universe in which it lives, the succession of time, the nature of space, cause and effect, its own existence, its ego and its relationship with other individuals of its own species. Do we get at any time in our life much beyond this? Not very much; we always use these things, which we learn in the first six months, as the foundation of all our thought. By eight months baby is upon the full career of experiment and observation. Everything with which the baby comes in contact interests him. He looks at it, he seizes hold of it, tries to pull it to pieces, studies its texture, its tensile strength, and every other quality it possesses. Not satisfied with that, he will turn and apply his tongue to it, putting it in his mouth for the purpose of finding out if it has any taste. In doing this, hour after hour, with unceasing zeal, never interrupted diligence, he rapidly gets acquainted with the world in which he is placed. At the same time he is making further experiments with his own body. He begins to tumble about; perhaps learns that it is possible to get from one place to another by rolling or creeping, and slowly he discovers the possibility of locomotion, which you know by the end of the year will have so far perfected itself that usually at twelve months the baby can walk. During this period of from five months to twelve the baby is engaged upon a career of original research, unaided much by anybody else, getting doubtless a little help and, of course, a great deal of protection, but really working chiefly by himself. How wonderful it all is! Is any one of us capable of beginning at the moment we wake to carry on a new line of thought, a new series of studies, and to keep it up full swing, with unabated pace, all day long till we drop asleep? Every baby does that every day.
