That which gives us the power of life is a combination of the material forces of Nature, and the elements that compose the brain are of a chemical substance. The difference between a "live" person and a "dead" one can be summarized by a great many instances about us, and because of their commonplaceness, we do not observe them.
There are many apples falling to the ground, but we are not inspired with the knowledge that the actuating force is gravity.
One of the best illustrations, to show the difference between a "live" and a "dead" person, can be had from that excellent invention called the "film" or "plate," and which is so remarkably used in the camera.
When that sensitive composition of chemicals that forms the "film" and which produces such a vivid and lasting likeness of ourselves is freshly made, it possesses that vital something we call "life."
But allow this film to remain unused for a period of time, and it will no longer be able to perform its remarkable work. It will not possess the "life" to take a picture or to record an impression.
If a premature "exposure" of the film is made, it loses its vital quality because of the mixture with other elements, or because of the evaporation of its constituent parts.
It is not necessary to analyze all the properties of that film to show the principle whereby it performs its wonderful work. The general principle, showing its marvelous use while intact and its utter uselessness when its composition is no longer the same, should be sufficient to illustrate the comparison.
This illustration can with force and conviction be applied to the peculiar quality and nature of our "soul" and brain. As long as the brain is incased within our skull, and fully protected from contact with any other substance to alter or to change its integrity, it will perform all that is warranted of it. In the case of our brain, though, besides the importance of keeping it protected from outside chemical action, the vital element concerned in its continuity of life lies in the importance of keeping it constantly nourished and supplied with the remarkable qualities of the vital substance of blood.
The moment the blood supply to the brain is stopped, our brain loses its most important constituent, with the ultimate and inevitable result of inertia, decomposition and decay. When this condition happens we are then "dead" and, like the proverbial egg, "all the King's horses and all the King's men cannot put Humpty Dumpty together again."
If we possessed a soul, and it were of a permanent and special quality, it would maintain its impressions and remember its existence.