It's a Satan thing.
They've got their own set of "laws,"
worked out long ago...
""Do what thou wilt shall be the whole of the Law" is a moral utterance found in the Thelemic foundation scripture, which is called the Book of the Law. "Do what thou wilt" is known as the Law of Thelema. It is derived from the rule of the fictional Abbey of Thélème in the classic satire Gargantua by the French priest and occult student François Rabelais. Crowley recommends study of Rabelais when discussing the Law. In Rabelais this rule was "fay çe que vouldras", French for "do what you will." From his work the maxim became a well-known part of Western literary life, and was adopted by the satirical English gentleman's society called the Hell-Fire Club or the Friars of Medmenham.
In Crowley's writing, the Law of Thelema is explained in terms of True Will, the ultimate spiritual core or quintessence of each person, which has a divinely self-ordained path through the world of experience. "Do what thou wilt" refers not to the outer emotional and intellectual self but to this sacred inner core of personal divinity. Often will is contrasted with whim, and the knowing and doing of the True Will is painted not in terms of license and ease but of responsibility and hard work.
Since this new law replaces outdated moral codes based around sins and forbidden acts, a person knowing and doing the will might appear to be sinful from a traditional viewpoint. In Crowley's view the Thelemite is following a demanding code requiring great personal integrity even while, for instance, making love in ways that would be illegal in oppressive societies. Sometimes it is natural to express this ironic inversion of traditional mores in satiric form, and Crowley, Rabelais and the Hell Fire Club all made heavy use of the satirical style in their writing and work."