In studying the Perennial Philosophy we can begin either at the bottom, with practice and morality; or at the top, with a consideration of metaphysical truths; or, finally, in the middle, at the focal point where mind and matter, action and thought have their meeting place in human psychology.
The lower gate is that preferred by strictly practical teachers men who, like Gautama Buddha, have no use for speculation and whose primary concern is to put out in men’s hearts the hideous fires of greed, resentment and infatuation. Through the upper gate go those whose vocation it is to think and speculate the born philosophers and theologians. The middle gate gives entrance to the exponents of what has been called “spiritual religion” the devout contemplatives of India, the Sufis of Islam, the Catholic mystics of the later Middle Ages…
Based upon the direct experience of those who have fulfilled the necessary conditions of such knowledge, this teaching is expressed most succinctly in the Sanskrit formula, tat tvam asi (‘That art thou’); the Atman, or immanent eternal Self, is one with Brahman, the Absolute Principle of all existence; and the last end of every human being is to discover the fact for himself, to find out Who he really is.
Aldous Huxley – The Perennial Philosophy