Spirituality is not about a philosophical idea or development of logic structures; rather, it is about actual experience in consciousness. The attempt to describe the conscious experience in language leads to various imperfect formulations that seek to convey a sense or meaning to the mind, while not actually reproducing the state of consciousness itself. Different emphasis or interpretation thus can lead to different transcriptions of the experience.
Sri Aurobindo observes that both Sankhya and Vedanta provide basic formulations that have their inception in the experience of the passive, immobile, immutable awareness of the Eternal. Sankhya posits the separation of the witness consciousness, the Purusha and the active nature, Prakriti. So long as the Purusha remains attached to the action of Nature, it is bound; but when it realizes that it is the pure, immutable Self of existence, and drops the attachment, then it is free. “The Vedantic view of the same status led to the philosophy of the inactive Self or Brahman as the one reality and of all the rest as name and form imposed on it by a false activity of mental illusion which has to be removed by right knowledge of the immutable Self and refusal of the imposition. The two views really differ only in their language and their viewpoint; substantially, they are the same intellectual generalisation from the same spiritual experience.”
The experience is described poetically in the Shwetashwatara Upanishad: “There is One, unborn, white and black and red, who is ever bringing forth many creatures with forms and her one unborn loves and cleaves to and lies with her; another unborn abandons, when all her enjoyments have been enjoyed. Two winged birds cling about a common tree, comrades, yoke-fellows; and one eats the sweet fruit of the tree, the other eats not, but watches. The Soul upon a common tree is absorbed and because he is not lord, grieves and is bewildered; but when he sees and cleaves to that other who is the Lord, he knows that all is His greatness and his sorrow passes away from him.” (Sri Aurobindo, The Upanishads, Shwetashwatara Upanishad, Chapter 4, v. 5-7, pg. 370)
Sri Aurobindo, The Synthesis of Yoga, Part Two: The Yoga of Integral Knowledge, Chapter 14, The Passive and the Active Brahman, pp. 386-387