While it is an eminently practical teaching, the Gita occasionally needs to elucidate principles in order to help our mind’s organize information in a suitable and useful way. Sri Aurobindo points out that while the Gita tries to avoid needless philosophical statements, it does provide the necessary information as a basis for the practical application that it requests of the seeker. The Gita also always has an eye on the prevalent philosophical positions that were current in its day, and it has taken pains to address each of these and put them into the context of its wide and embracing understanding of the truth of existence. At this point the Gita needs to integrate the ultimate reality, known in the Upanishads as the Brahman, with the creation of the universe and its manifested forms. It does this by successively revealing five principles.
Sri Aurobindo itemizes these five principles (with their Sanskrit terms) as follows: “First there is that Brahman, tad brahma; adhyatma, second, the principle of the self in Nature; adhibhuta and adhidaiva next, the objective phenomenon and subjective phenomenon of being; adhiyajna last, the secret of the cosmic principles of works and sacrifice.”
These terms are further clarified as follows: “By that Brahman, a phrase which in the Upanishads is more than once used for the self-existent as opposed to the phenomenal being, the Gita intends, it appears, the immutable self-existence which is the highest self-expression of the Divine and on whose unalterable eternity all the rest, all that moves and evolves, is founded….By adhyatma it means svabhava, the spiritual way and law of being of the soul in the supreme Nature. Karma, it says, is the name given to the creative impulse and energy…which looses out things from this first essential self-becoming, this Swabhava, and effects, creates, works out under its influence the cosmic becoming of existences in Prakriti. By adhibhuta is to be understand all the result of mutable becoming…. By adhidaiva is intended the Purusha, the soul in Nature, the subjective being who observes and enjoys as the object of his consciousness all that is this mutable becoming of his essential existence worked out here by Karma in Nature. By adhiyajna, the Lord of works and sacrifice, I mean, says Krishna, myself, the Divine, the Godhead, the Purushottama here secret in the body of all these embodied existences. All that is, therefore, falls within this formula.”
Sri Aurobindo, Essays on the Gita, Second Series, Part I, Chapter 3, The Supreme Divine, pp. 277-278