The second part of the Kena Upanishad contains 5 verses that explore the possibilities of “knowing”, the process of knowing, and the limitations of the process of knowing. It enunciates the limits of linear thinking of the mind, and sets the understanding of what must be done to acquire true knowledge and overcome the limits of the mental framework and capacities. Each one takes up a separate aspect of the process and limits of knowing. At the same time, it explores the relation of the Absolute Brahman to the world of creation, making the point that the Absolute Brahman cannot be known through action of the mind.
Second part, verse 1: “If thou thinkest that thou knowest It well, little indeed dost thou know the form of the Brahman. That of It which is thou, that of It which is in the gods, this thou has to think out. I think It known.”
Sri Aurobindo observes: “The Master-Consciousness of the Brahman is that for which we have to abandon this lesser status of the mere creature subject to the movement of Nature in the cosmos; but after all this Master-Consciousness, however high and great a thing it may be, has a relation to the universe and the cosmic movement; it cannot be the utter Absolute, Brahman superior to all relativities. This Conscious-Being who originates, supports and governs our mind, life, senses is the Lord; but where there is no universe of relativities, there can be no Lord, for there is no movement to transcend and govern. Is not then this Lord, as one might say in a later language, not so much the creator of Maya as himself a creation of Maya? Do not both Lord and cosmos disappear when we go beyond all cosmos? And is it not beyond all cosmos that the only true reality exists? Is it not this only true reality and not the Mind of our mind, the Sense of our sense, the Life of our life, the Word behind our speech, which we have to know and possess? As we must go behind all effects to the Cause, must we not equally go beyond the Cause to that in which neither cause nor effects exist? Is not even the immortality spoken of in the Veda and Upanishads a petty thing to be overpassed and abandoned?: and should we not reach towards the utter Ineffable where mortality and immortality cease to have any meaning?”
Sri Aurobindo, The Upanishads, Kena Upanishad and analysis, pp. 103-104, 165-170