A man is never tempted by a woman who does not attract him.
He never steals a thing he does not want. He does not drink a liquor he does not like. The desire must be there before his will is put to the test. And the desire is independent of his will.
A child has no morals. It has only desires. If it likes sugar it will take sugar. If it is angry it will strike. It is only when it is told that to steal sugar or strike its nurse is "naughty" that it begins to have a moral sense. And its moral sense consists entirely of what it learns—that is to say, its moral sense is memory. And its memory is a change in the arrangement of the cells of the grey matter of the brain. And these changes make the brain into a different kind of brain: make the child into a different kind of child.
Now, the child does not teach itself these moral lessons. It does not know them. It has to be taught by those who do know. And its moral sense depends upon what it is taught. And its conscience depends upon what it is taught.
And, that being so, is it not quite evident that the conscience is not the voice of God; that the conscience is not an innate knowledge of right and wrong born with the child; but it is nothing more nor less than the action of the memory?
The whole of this subject is ably and exhaustively treated by Luys in "The Brain and Its Functions," but I have not room here to go into it fully. Briefly put, the scientific explanation may be expressed thus: The brain cells have power to receive and to repeat impressions. When a new sensory impulse arises it awakens these impressions by means of the fibres of association. It is as though the brain were a phonographic "record." Upon this "record" there is printed, let us say, some moral lesson, as "Look not upon the wine when it is red in the cup." On the word "wine" being heard the association fibre which links the idea of wine to the moral idea of temperance sets the "record" in motion, and memory recalls the caution, "Look not upon the wine in the cup." It is as if a "record" on which is printed a song by Dan Leno were joined up with a battery which, upon hearing the word "Leno," would start the "record" to repeat the song.
I hope I have made that clear. I will now conclude by quoting from Dr. Saleeby a passage dealing with the important subject of "association." I take it from "The Cycle of Life":
Nerve cells are significantly incapable of division and reproduction.... All the experience of living merely modifies, the state of the cells already present. The modification is memory.
But though a nerve-cell cannot divide, it can send forth new processes, or nerve-fibres from itself—what we call a nerve being simply a collection of processes from a nerve-cell. Throughout the brain and spinal cord we find great numbers of nerve processes which simply run from one set of nerve-cells to another, instead of running to a sense-organ, or a muscle, or a gland. Such fibres are called association fibres, their business being to associate different sets of nerve-cells.
It is conceivable that an exceptional development of such fibres may account for the possession of a good memory, or, at any rate, for the power easily to learn such co-ordinations as are implied in violin-playing, billiards, cricket, or baseball. Granting the power of nerve-cells, even when adult, to form new processes, it might be supposed that the exercise of this power accounts for the acquirement of certain habits of thought or action.