Sri Aurobindo translates Verse 3, Chapter 2, Section 2 of Mundaka Upanishad: “Take up the bow of the Upanishad, that mighty weapon, set to it an arrow sharpened by adoration, draw the bow with a heart wholly devoted to the contemplation of That, and O fair son, penetrate into That as thy target, even into the Immutable.”
The Upanishads make it clear that knowledge acquired through the action of the mind and the reasoning powers cannot grasp or encompass a knowledge of the Eternal, the Immutable, the Absolute, the Ananda of the Brahman. The Taittiriya Upanishad says it clearly “The delight of the Eternal from which words turn away without attaining and the mind also returneth baffled, who knoweth the delight of the Eternal?” If the higher knowledge cannot be attained through the action of the mental faculties, the question arises as to whether there is any method of attainment possible, and if so, what that method is. The current verse answers that such knowledge is possible and a method is set forth.
The mind must be brought to a place of basic understanding of its limits, and of the existence of a higher form of knowledge, which is the role of the Upanishad. Adoration and total contemplation are the stance that the soul takes in its aspiration to move beyond the mind’s activity to achieve a knowledge by identity with the Brahman.
In The Life Divine, Sri Aurobindo discusses the different types of knowledge and their action in the chapter titled Knowledge by Identity and Separative Knowledge (pp. 524-552). He states “The original and fundamental way of knowing, native to the occult self in things, is a knowledge by identity…. The first way of knowing in its purest form is illustrated in the surface mind only by our direct awareness of our own essential existence: it is a knowledge empty of any other content than the pure fact of self and being; of nothing else in the world has our surface mind the same kind of awareness.”
In his lectures on Raja Yoga, Swami Vivekananda describes the methods of attaining the state of Samadhi, which is a state of direct knowledge by identity with the Eternal. He describes the “mind stuff” (“chitta”) as always being in motion and the goal of the practice is to bring the mind stuff to a state of stillness and thereby allow it to reflect the Eternal. The Upanishad references a state of total contemplation on the Absolute achieved with a heart of adoration. We see here then an outline of how the higher knowledge can be achieved.
The question naturally arises as to how anyone can undertake action in the world, using the other methods of knowing, and relating to what the Upanishad calls the lower knowledge. This is obviously a separate subject which only has real relevance when once the knowledge by identity has actually been achieved. The short answer is that a knowledge by identity completely and immediately incorporates the knowledge of the world and its significance and actions, and thus, the goal of the Upanishads, to know “that by knowing which all is known” is clearly before us.
Sri Aurobindo, The Upanishads, Mundaka Upanishad, pp. 193-210