Sri Aurobindo translates Aitareya Upanishad, Chapter 1, Section 2: “These were the Gods that He created; they fell into this great Ocean, and Hunger and Thirst leaped upon them. They they said to Him, ‘Command unto us an habitation that we may dwell secure and eat of food.’ He brought unto them the cow, but they said, ‘Verily, it is not sufficient for us.’ He brought unto them the horse, but they said, ‘Verily, it is not enough for us.’ He brought unto them Man, and they said, ‘O well fashioned truly! Man indeed is well and beautifully made.’ Then the Spirit said unto them, ‘Enter ye in each according to his habitation.’ Fire became Speech and entered into the mouth; Air became Breath and entered into the nostrils; the Sun became Sight and entered into the eyes; the Quarters became Hearing and entered into the ears; Herbs of healing and the plants and trees became Hairs and entered into the skin; the Moon became Mind and entered into the heart; Death became apana, the lower breathing, and entered into the navel; the Waters became Seed and entered into the organ. Then Hunger and Thirst said unto the Spirit, ‘Unto us too command an habitation.’ But He said unto them, ‘Even among these gods do I apportion you; lo! I have made you sharers in their godhead.’ Therefore to whatever god the oblation is offered, Hunger and Thirst surely have their share in the offering.”
The Gods in the Vedic sense represent the conscious powers of the Brahman put forth for the universal manifestation. The Upanishad now provides the linkage between the universal forces and their action in the human being. The various senses, both of perception and of action, are each related to the action of one of the universal forces and has its own organ through which it operates. These are detailed here.
The world-action is driven along in its course through the operation of the force of desire, seen here as Hunger and Thirst. Once the experience of separation takes place, the separated parts feel something lacking or missing and work to reintegrate that missing element. The involution of consciousness into matter through the process of fragmentation into individual forms represents the ultimate sense of separation. As consciousness evolves out of matter through life, mind and beyond, it successively gains the power of recognising and experiencing the Oneness. The first promptings are those we call desire. This drive works at each level, whether we call it the swallowing of one galaxy by another, or the devouring of one form of material life to enhance another form’s existence. At higher stages, the union takes place through harmonising of energetic action, through emotional and mental joining, with the perceived “lack” appearing as the search for union and the seeking of knowledge, and eventually, through the spiritual development, to the ultimate union of yoga, where the seeker experiences oneness with Brahman and experiences the creation from that standpoint, at which point the role of desire in its various formations has ended..
Sri Aurobindo, The Upanishads, Aitareya Upanishad, pp.285-294