In The Life Divine, Sri Aurobindo analyzes the issues raised here in the Isha Upanishad in his discussion of “the materialist denial” and “the refusal of the ascetic”. These represent two paths of knowledge, taken to their extreme. The “materialist denial” focuses on what the Upanishad terms “Ignorance” (Avidya). It is itself a powerful path of knowledge, but isolated from the greater truth of what Sri Aurobindo calls “reality omnipresent”. The “refusal of the ascetic” focuses on what the Upanishad terms “Knowledge”. Once again, this is a powerful path of knowledge, but isolated and incomplete.
The Isha Upanishad makes clear that either path, followed exclusively, leads to “darkness” but the path of “Knowledge” actually appears to lead to a greater darkness.
Sri Aurobindo observes: “Although a higher state than the other, this supreme Night is termed a greater darkness, because the lower is one of chaos from which reconstitution is always possible, the higher is a concept of Void or Asat, an attachment to non-existence of Self from which it is more difficult to return to fulfilment of Self.”
“Pursued with a less entire attachment the paths of Vidya and Avidya have each their legitimate gains for the human soul, but neither of these are the full and perfect thing undertaken by the individual in the manifestation. By Vidya one may attain to the state of the silent Brahman or the Akshara Purusha regarding the universe without actively participating in it or to His self-absorbed state of Chit in Sat (n.b. consciousness in existence) from which the universe proceeds and towards which it returns. Both these states are conditions of serenity, plenitude, freedom from the confusions and sufferings of the world.”
“But the highest goal of man is neither fulfilment in the movement as a separate individual nor in the Silence separated from the movement, but in the Uttama Purusha, the Lord, He who went abroad and upholds in Himself both the Kshara and the Akshara as modes of His being.”
“By Avidya one may attain to a sort of fullness of power, joy, world-knowledge, largeness of being,, which is that of the Titans or of the Gods, of Indra, of Prajapati. This is gained in the path of self-enlargement by an ample acceptance of the multiplicity in all its possibilities and a constant enrichment of the individual by all the materials that the universe can pour into him. But this also is not the goal of man; for though it brings transcendence of the ordinary human limits, it does not bring the divine transcendence of the universe in the Lord of the universe. One transcends confusion of Ignorance, but not limitation of Knowledge, — transcends death of the body, but not limitation of being, — transcends the lower Prakriti, but not the higher.”
“The real knowledge is that which perceives Brahman in His integrality and does not follow eagerly after one consciousness rather than another, is no more attached to Vidya than to Avidya.”
“Avidya fulfilled by turning more and more to Vidya enables the individual and the universal to become what the Lord is in Himself, conscious of His manifestation, conscious of His non-manifestation, free in birth, free in non-birth. Man represents the point at which the multiplicity in the universe becomes consciously capable of this turning and fulfilment. His own natural fulfilment comes by following the complete path of Avidya surrendering itself to Vidya, the Multiplicity to the Unity, the Ego to the One in all and beyond all, and of Vidya accepting Avidya into itself, the Unity fulfilling the Multiplicity, the One manifesting Himself unveiled in the individual and in the universe.”
Sri Aurobindo, The Upanishads, Isha Upanishad and analysis, pp. 21-23, 28 & 51-73