A Treatise on White Magic:

The soul, seated in the heart, is the life principle, the principle of self-determination, the central nucleus of positive energy by means of which all the atoms of the body are held in their right place and subordinated to the "will-to-be" of the soul. This principle of life utilizes the blood stream [454] as its mode of expression and as its controlling agency, and through the close relation of the endocrine system to the blood stream, we have the two aspects of soul activity brought together in order to make man a living, conscious, functioning entity, governed by the soul, and expressing the purpose of the soul in all the activities of daily living.
Death, therefore, is literally the withdrawal from the heart and from the head of these two streams of energy, producing consequently complete loss of consciousness and disintegration of the body. Death differs from sleep in that both streams of energy are withdrawn. In sleep, only the thread of energy which is anchored in the brain is withdrawn, and when this happens the man becomes unconscious. By this we mean that his consciousness or sense of awareness is focused elsewhere. His attention is no longer directed towards things tangible and physical, but is turned upon another world of being and becomes centered in another apparatus or mechanism. In death, both the threads are withdrawn or unified in the life thread. Vitality ceases to penetrate through the medium of the blood stream and the heart fails to function, just as the brain fails to record, and thus silence settles down. The house is empty. Activity ceases, except that amazing and immediate activity which is the prerogative of matter itself and which expresses itself in the process of decomposition. From certain aspects, therefore, that process indicates man's unity with everything that is material; it demonstrates that he is a part of nature itself, and by nature we mean the body of the one Life in Whom "we live and move and have our being." In those three words - living, moving and being - we have the entire story. Being is awareness, self-consciousness and self-expression, and of this man's head and brain are the exoteric symbols. Living is energy, desire in form, coherence and adhesion to an idea, and of this the heart and the blood are the exoteric [455] symbols. Moving indicates the integration and response of the existing, aware, living entity into the universal activity, and of this the stomach, pancreas and liver are the symbols.
It must be noted also that death is, therefore, undertaken at the direction of the Ego, no matter how unaware a human being may be of that direction. The process works automatically with the majority, for (when the soul withdraws its attention) the inevitable reaction on the physical plane is either death, by the abstraction of the dual threads of life and reason energy, or by the abstraction of the thread of energy which is qualified by mentality, leaving the life stream still functioning through the heart, but no intelligent awareness. The soul is engaged elsewhere and occupied on its own plane with its own affairs.
- Pages 496-497.

Before I take up this subject in greater detail I would like to make some reference to the "web in the brain," which is intact for the majority but is non-existent for the illumined seer.
In the human body, as you know, we have an underlying, extensive vital body which is the counterpart of the physical, which is larger than the physical and which we call the etheric body or double. It is an energy body and is composed of force centers and nadis or force threads. These underlie or are the counterparts of the nervous apparatus - the nerves and the nerve ganglia. In two places in the human body there are orifices of exit, if I may use so cumbersome a phrase. One opening is in the solar plexus and the other is in the brain at the top of the head. Protecting both is a closely woven web of etheric matter, composed of interlacing strands of life energy.
During the process of death the pressure of the life energy beating against the web produces eventually a [456] puncturing or opening. Out of this the life force pours as the potency of the abstracting influence of the soul increases. In the case of animals, of infants and of men and women who are polarized entirely in the physical and astral bodies, the door of exit is the solar plexus, and it is that web which is punctured, thus permitting the passing out. In the case of mental types, of the more highly evolved human units, it is the web at the top of the head in the region of the fontanel which is ruptured, thus again permitting the exit of the thinking rational being.
In the process of death these are, therefore, the two main exits: the solar plexus for the astrally polarized, physically biased human being, and therefore of the vast majority, and the head center for the mentally polarized and spiritually oriented human being. This is the first and most important factor to remember, and it will easily be seen how the trend of a life tendency and the focus of the life attention determine the mode of exit at death. It can be seen also that an effort to control the astral life and the emotional nature, and to orient one's self to the mental world and to spiritual things, has a momentous effect upon the phenomenal aspects of the death process.
If the student is thinking clearly, it will be apparent to him that one exit concerns the spiritual and highly evolved man, whilst the other concerns the low grade human being who has scarcely advanced beyond the animal stage. What then of the average man? A third exit is now in temporary use; just below the apex of the heart another etheric web is found covering an orifice of exit. We have, therefore, the following situation:

This is the first point in the new information which will slowly become common knowledge in the West during the next century. Much of it is already known by thinkers in the East and is in the nature of a first step towards a rational understanding of the death process.
- Page 500.