sādhibhūta iti tridhā
virāṭ prāṇo daśa-vidha
ekadhā hṛdayena ca
In Bhagavad-gītā (7.4-5) it is stated that the eight elements earth, water, fire, air, sky, mind, intelligence and false ego are all products of the Lord’s inferior energy, whereas the living entities, who are seen to utilize the inferior energy, originally belong to the superior energy, the internal potency of the Lord. The eight inferior energies work grossly and subtly, whereas the superior energy works as the central generating force. This is experienced in the human body. The gross elements, namely earth, etc., form the external gross body and are like a coat, whereas the subtle mind and false ego act like the inner clothing of the body.
The movements of the body are first generated from the heart, and all the activities of the body are made possible by the senses, powered by the ten kinds of air within the body. The ten kinds of air are described as follows: The main air passing through the nose in breathing is called prāṇa. The air which passes through the rectum as evacuated bodily air is called apāna. The air which adjusts the foodstuff within the stomach and which sometimes sounds as belching is called samāna. The air which passes through the throat and the stoppage of which constitutes suffocation is called the udāna air. And the total air which circulates throughout the entire body is called the vyāna air. Subtler than these five airs, there are others also. That which facilitates the opening of the eyes, mouth, etc., is called nāga air. The air which increases appetite is called kṛkara air. The air which helps contraction is called kūrma air. The air which helps relaxation by opening the mouth wide (in yawning) is called devadatta air, and the air which helps sustenance is called dhanañjaya air.
All these airs are generated from the center of the heart, which is one only. This central energy is superior energy of the Lord, who is seated within the heart with the soul of the body, who acts under the guidance of the Lord. This is explained in Bhagavad-gītā (15.15) as follows:
sarvasya cāhaṁ hṛdi sanniviṣṭo
mattaḥ smṛtir jñānam apohanaṁ ca
vedaiś ca sarvair aham eva vedyo
vedānta-kṛd veda-vid eva cāham
The complete central force is generated from the heart by the Lord, who is seated there and who helps the conditioned soul in remembering and forgetting. The conditioned state is due to the soul’s forgetfulness of his relationship of subordination to the Lord. One who wants to continue to forget the Lord is helped by the Lord to forget Him birth after birth, but one who remembers Him, by dint of association with a devotee of the Lord, is helped to remember Him more and more. Thus the conditioned soul can ultimately go back home, back to Godhead.
This process of transcendental help by the Lord is described in Bhagavad-gītā (10.10) as follows:
dadāmi buddhi-yogaṁ taṁ
yena mām upayānti te
The buddhi-yoga process of self-realization with intelligence transcendental to the mind (devotional service) can alone elevate one from the conditioned state of material entanglement in the cosmic construction. The conditioned state of the living entity is like that of a person who is within the depths of a huge mechanical arrangement. The mental speculators can reach the point of buddhi-yoga after many, many lifetimes of speculation, but the intelligent person who begins from the platform of intelligence above the mind makes rapid progress in self-realization. Because the buddhi-yoga process entails no fear of deterioration or retrogression at any time, it is the guaranteed path to self-realization, as confirmed in Bhagavad-gītā (2.40). The mental speculators cannot understand that the two birds (Śvetāśvatara Upaniṣad) sitting in one tree are the soul and the Supersoul. The individual soul eats the fruit of the tree, while the other bird does not eat the fruit but only observes the activities of the eating bird. Without attachment, the witnessing bird helps the fruit-eating bird perform fruitful activities. One who cannot understand this difference between the soul and the Supersoul, or God and the living entities, is certainly still in the entanglement of the cosmic machinery and thus must still await the time when he will be free from bondage.