The original scriptures of most religions are poetical and unsystematic. Theology, which generally takes the form of a reasoned commentary on the parables and aphorisms of the scriptures, tends to make its appearance at a later stage of religious history. The Bhagavad-Gita occupies an intermediate position between scripture and theology; for it combines the poetical qualities of the first with the clear-cut methodicalness of the second… one of the clearest and most comprehensive summaries of the Perennial Philosophy ever to have been made. Hence its enduring value, not only for Indians, but for all mankind.

Introduction to the Bhagavad-Gita (1944)