36: "This whole solar system being conceived of as one vast mechanism, with an exquisite adjustment of its parts in all major details, is only the physical expression of Vishnu, or the ethereal basic substance, as we may understand the word for the present.  All the harmonies observable in the manifested cosmos are only the result of the harmoniously working energies that resolve ether into the expression that we recognise.  All planets, worlds, human beings, etc., are only parts of the body, each functioning in subordination to the law which governs the whole.  The evolution, preservation and destruction of the world is therefore one vast process called Yagna, which takes place in the body of Yagna Purusha, or the psychical body of nature.  Humanity taken collectively is the heart and brain of this Purusha and therefore all the Karma generated by humanity, physical, mental, or spiritual, determines mainly the character of this Yagnic process....Sri Krishna therefore calls the process the Yagnic life that he has been giving out to Arjuna as Yoga (1st Sloka 4th Chr).  In fact, Yoga and Yagna are very closely allied and even inseparable, though at the present day people seem to disconnect the two.  Yoga derived from the root Yuj to join means an act of joining.  Now as the heart is the great centre in man, likewise the Yogee of the heart keeps his central position in the universe and hence his individuality.  The individuality or the Higher Manas being the pivot of the human constitution or the centre on which two hemispheres of higher and lower existence turn as I have already said, the Yogee of the heart has a heavenly dome above and earthly abyss below and his yoga becomes twofold as a consequence.  He joins himself on to the thing above in dhyana and the thing below in action.  The word yagna derived from the root Yaj—to serve also means a twofold service, service done to the thing above through service done unto its expression the thing below."—Some Thoughts on the Gita, pp. 18, 134.