Kenopanishad is a sandhi of kena and upanishad. Kena means 'by whom'. Kenopanishad tries to explain to the stuent of life 'by whom' this world and all its doings are powered. The entire Upanishad is in conversation style. The student of life has grown up and has rejected the world as a field of meaningless strife and the day to day material life as an endless race to catch ones own shadow. Thus rejecting the false, he starts to enquire upon himself.
In the first chapter, the student finds out that neither the assembly of his limbs nor his sense organs nor his mind, or his intellect can, of their own accord, function without a vitalizing principle, the Vital Air (the Prana) behind them all. At this the student feels he has understood the Brahman. However, the teacher explains that what the student has seen is only a little portion of the whole. The teacher also tells that the real Brahman is that power that is behind every sense organ. The Eye behind eyes,the Ear behind d ears,the Tongue of the tongue, The Mind of the mind and also the Life of the life and not the what people have come to worship in this material world.
In the second chapter, The teacher warns the student not have the misconception of having understood the Brahman. He explains that the Brahman has to be realised on ones own acccord and it cannot be explained. In response the student retorts that he has not yet understood the Brahman. But when he looks within himself, he replies that he has partly understood the Brahman.The teacher then brings to light another truth that, all the things that we grasp and understand are based on the principles of/in relation to the already comprehended ideas in our mind. Therefore the Truth is not the konwn but essentially the unkown. In the fourth mantra the teacher explains that the Absolute Truth presiding in us as the self is 'known well' only when it is knowingly understood as the withness of the three states of consciousness. That factor in us, in consultation with which this continuity of awareness and personality, through the different fields of consciousness, is the All-Witnessing Atman.
The third chapter is a story which is a symbolic representation of the Truth. Once the divines won a victory over the evil forces. The victory must have been credited to the power of the Absolute Brahman. Instead the divines thought it was theirs. Brahman appeared before them in a visible form of a spirit (yaksha) but they did not recognize the Absolute. One by one, Agni the God of fire and Vayu the God of air, came to challenge this new appearance in and tried to show off their powers. The God of Fire could not burn even the straw placed before him. The God of air could not blow even the straw placed before him. Finally Indra the God of all the divines came nearest to that spirit to find out who it is that is presenting these challenges to the divines. And before him stood Mother Goddess Herself in the name and form of Uma.
In the fourth Chapter it is shown that Lord Indra becomes the first persont o recognise the spirit as the Brahman and is blessed to become the King of Gods because he was nearest to the Brahman. The Brahman is also decribed, the splendour with which he shone and how he disappeared. The Brahman is well known as Tadvanam, the teacher gives a method of meditation to the lesser students who cannot comprehend the divine.
In conclusion. This is the truth of the Brahman in relation to nature and man. The sudden Reality that strikes Man as the power behind everything must be transformed into a permanant Realization.
Compiled from:- Wikipedia and Kenopanishad by Swami Chinmayananda