And while, of course, the sensational _knowledge_ is being secreted in the brain, in some much more mysterious way the living individuality of the child is being developed in the four first nuclei, the four great nerve-centers of the primary field of consciousness and being.
As time goes on, the child learns to see the mother. At first he sees her face as a blur, and though he knows her, knows her by a direct glow of communication, as if her face were a warm glowing life-lamp which rejoiced him. But gradually, as the circuit of touch, taste, and smell become powerfully established; gradually, as the individual develops in the child, and so retreats towards isolation; gradually, as the child stands more immune from the mother, the circuit of correspondence extends, and the eyes now communicate across space, the ears begin to discriminate sounds. Last of all develops discriminate hearing.
Now gradually the picture of the mother is transferred to the child's mind, and the sound of the first baby-words is imprinted. And as the child learns to discriminate visually, objectively, between the mother and the nurse, he learns to choose, and becomes individually free. And still, the dynamic correspondence is not finished. It only changes its circuit.
While the brain is registering sensations, the four dynamic centers are coming into perfect relation. Or rather, as we see, the reverse is the case. As the dynamic centers come into perfect relation, the mind registers and remembers sensations, and begins consciously to know. But the great field of activity is still and always the dynamic field. When a child learns to walk, it learns almost entirely from the solar plexus and the lumbar ganglion, the cardiac plexus and the thoracic ganglion balancing the upper body.
There is a perfected circuit of polarity. The two lower centers are the positive, the two upper the negative poles. And so the child strikes out with his feet for the earth, presses, and strikes away again from the earth, the two upper centers meanwhile corresponding implicitly in the balance of the upper body. It is a chain of spontaneous activity in the four primary centers, establishing a circuit through the whole body. But the positive poles are the lower centers. And the brain has probably nothing at all to do with it. Even the _desire_ to walk is not born in the brain, but in the primary nuclei.