When we speak of the constitution of man, we are apt, at first thought, to visualize the physical body, its parts and organs. Upon second and more deliberate thought, however, we realize that the physical body is not, by far, the only or most important part of the constitution of man.
Upon careful consideration, we find that the common sense perceptions do not lie in the body. For instance, we are told that light is a vibration in the ethers, or that it is a substance emitted from a light-giving object. These vibrations or this light-substance strike the mechanism of the eye and are carried to the "sight-center" of the brain. There a miracle takes place. The vibration or light-substance is transformed or transmuted into a sensation, that is, into a state of consciousness.
Note well — the vibration or "light-substance" has become a state of consciousness! In what part of man's constitution lies the center of consciousness? Where lies the "transformer" between "vibration" and "consciousness'?
The Ancient Wisdom, Theosophy, teaches the existence of a finer, more subtle model body, commonly called the Astral Body. A study of this Astral Body enables one to discover the answer to many questions like the above.
Life! What is life? Where does it originate? How does it get into our body? Is it strictly an energy? Theosophy tells us of the "ocean of life-substance-energy" in which our whole globe is bathed. That part of this ocean of universal life-substance-energy active or at work in a man's body is spoken of as Prana, the life-principle.
Where lies Will? Where lies Desire? Desire or Kama is the "power-principle," neither good nor bad, except as it is controlled and guided.
Controlled and guided! — by what? The Ancient Wisdom teaches that the real man is the Thinker, the part of himself who thinks and reasons, and guides, as best he knows how, the lower principles.
But thought, the thinker, and consciousness are not one thing, or even aspects of one thing. Above thought and the Thinker is a center of consciousness, of conscience. Conscience is not a necessary function of the brain-mind, which is apt to confuse right with expediency, and justice with might. But there is inherent in every man a spiritual sense of right and justice, a sense of compassion and love. These, Theosophy teaches, lie in a spiritual center, called Buddhi.
Man speaks of "my body, my mind, my soul, my spirit!" What is this "I" of which these are attributes and appurtenances? It is the God within, the Divine Spark, rooted in the heart of the Universe Itself!