The soul is the vital principle of the material body, where its influence is everywhere. Consciousness manifests itself by exerting its influence throughout the body; it is the proof of the presence of the soul, which is its source. All those who are enlightened by the knowledge of the data of spiritual science know that the body deprived of consciousness is a lifeless object, which nothing can revive.
In truth, the energy of the soul spread throughout the body is what is called consciousness. It is because consciousness is spread throughout the organism that the being experiences sensations of pain or pleasure in every part of his body.
If the soul (each of us is in truth an individual soul distinct from God), is the possessor of the body in which it is incarnated, let us understand that God is the Supreme possessor.
In truth, in spite of its infinitesimal size, the soul measures only one ten thousandth of the tip of a hair, it possesses a great power which enables it to make the body function, and by its vital force to keep it alive. If it leaves the body, the latter collapses without life.
The soul is actually a spiritual atom, a particle of spiritual energy, also called a spiritual spark, a tiny fragment of the Supreme Person, Krishna.
It is unborn and therefore immortal. It is not created at the moment the body is formed, nor does it die at the moment the body ceases to live. Only that which is born must also die. The soul has no past, present or future. It is eternal and original. Nor does it age like the body, and changes of body do not affect it. Nor does it beget offspring. While we cannot perceive the presence of the soul in the heart where it resides, we can still apprehend its existence through the consciousness that emanates from it.
It has the presence of God who resides in the heart with it and who activates and enlivens for it the various senses, the vital breath, the heart, the mind and makes them come alive. She can then take command of the body and act as she wishes, since the Lord allows her to do so.
The truth is that the energy for the functioning of the body comes from the heart simply because the spirit soul distinct from God is present there along with the Supreme Lord in the form of the Supreme Soul, and they are both present there. It is because the heart pumps blood and spreads it throughout the body that the body is animated. The function of the heart is to pump the blood and transmit it throughout the body.
The red blood cells, which carry the oxygen stored in the lungs, draw their energy from the soul. This is why the blood ceases to circulate and perform its functions as soon as the soul leaves the body. The soul provides the body with its vital energy, and the heart is the seat of all bodily energies.