This is a short doctrinal epistle by Aleister Crowley, first published in *The Equinox* (1919), expounding the central law of Thelema — the occult-philosophical system he founded — drawn from *The Book of the Law*. The piece argues that "Do what thou wilt" is not a license for hedonism but a demanding spiritual mandate: each person has a singular, true Will, and virtue consists entirely in discovering and executing that Will with single-minded purity, free from distraction, desire for outcomes, or competing intentions. Crowley draws an analogy to stars moving in fixed orbits — if everyone followed their true Will, there would be no conflict, since genuine individual purposes do not clash. A distinctive claim is the identification of personal True Will with divine will: perfectly aligned self-will is, in Crowley's framing, identical to the Will of God, and therefore "Thou art That" — a non-dualist conclusion notable for its borrowing from Vedantic thought. The epistle closes by subordinating Love to Will: love is real but secondary, described as a "by-product" that must never override Will when the two appear to conflict. The tone is authoritative and exhortatory, written as instruction to initiates rather than as philosophical argument.