Writing in Liber Aleph, Crowley says:
Now the Path of Ayin is a Link between Mercury and the Sun, and in the Zodiac importeth the Goat. This Goat is called also Strength, and standeth in the Meridian at the Sunrise of Spring; and it is His Nature to leap upon the Mountains. So therefore he is a Symbol of true Magick, and his Name is Baphomet, wherefore did I design him as an Atu of Thoth, the Fifteenth, and put his Image in the Front of my Book, The Ritual of High Magick, which was the second Part of my Thesis for the Grade of Major Adept, when I was clothed about with the Body called Alphonse Louis Constant. Now the Goat flieth not as doth the Eagle; but consider this also that it is the true Nature of Man to dwell upon the Earth, so that his Flights are oft but Phantasy; yea, the Eagle also is bound to his Eyrie, nor feedeth upon Air. Therefore this goat, making each leap with Fervour, yet all Times secure in his own Element, is a true Hieroglyph of the Magician. Mark also, this Path sheweth One continuous in Exaltation upon a Throne, and so is it the Formula of the Man, as the other [Nun] was of the Woman.
Liber Aleph, “SEQUITUR DE HIS VIIS” (emphasis mine)
The magick of Baphomet is the magick of strength and freedom upon the surface of the Earth. It is about the realization of one’s divinity in the context of an individual life.
Every man and every woman is a star—that is, as Crowley reminds us in the initiation rituals of O.T.O., they are an adventuring god. This god’s adventures lead it into contact with matter. This interaction with embodied, incarnated existence will lead to the loss of our sense of our divinity. The magick represented by the symbol of Baphomet will lead us back to our true natures—in this life, not in death—and with that self-knowledge will come mastery over the conditions of life, so that life is enjoyed more like a great adventure than a burden.
In a letter to Charles Stansfeld Jones, Crowley gives us the word through which that magick is to be worked:
I have got my A∴A∴ grade … and that too, exactly at the time prophesied. … I must do my duty … and that is to preach my Law. Therefore this is the Word of Baphomet to all the members of the O.T.O.: ΘΕΛΗΜΑ … One must take some very simple, very deep word which cuts at the heart of things. … I say ΘΕΛΗΜΑ. Go on, therefore, preaching this and nothing else in season and out of season. You won’t have to wait long for results.
Letter from Aleister Crowley to Charles S. Jones, October 4, 1915 e.v.
Thelema is the word of the Law proclaimed in The Book of the Law. The whole of that Law is Do what thou wilt.
Writing in Liber II: The Message of the Master Therion, Crowley says:
It is the apotheosis of Freedom; but it is also the strictest possible bond. Do what thou wilt—then do nothing else. Let nothing deflect thee from that austere and holy task. Liberty is absolute to do thy will; but seek to do any other thing whatever, and instantly obstacles must arise. Every act that is not in definite course of that one orbit is erratic, an hindrance. Will must not be two, but one.
Liber II, The Message of the Master Therion
The Law of Thelema is the key to the self-realization of one’s own divinity and the mastery of life in the context of this incarnation. It also contains within itself the union of freedom and the strictest possible bonds of self-discipline. The understanding of this Law with its demands and rewards gives one the best possible chance to make the most of a human life.