"Do what thou wilt"
Frequently I come across magical practitioners who speak of exploring Aleister Crowley's Thelema who then misquote "Do what thou wilt shall be the whole of the law" as a justification for doing all that they wish. Worse yet, I have seen some who explore this phrase as the justification to what practicing what they call "black magic" in a very similar sense - simply doing what they wish, because they wish it.
This is a grave misinterpretation of the words of a man whose magical exploration within the Hermetic Order of the Golden Dawn, and subsequent work on his own, helped to form the backbone of the occult traditions that we experience in modern day. Indeed, his works (and those of the Golden Dawn) undoubtedly influenced Gardner in his creation of Wicca, as well as helped to popularize such practices as Yoga, meditation, and the Hindu exploration of the spirituality that we see so deeply co-mingled within Western magical traditions.
Are we to believe then that this quote, summing up the whole of the law for Thelema - the spiritual tradition founded by Crowley - was simply the go-ahead to do whatever you want? Are the teachings of a man who helped provide us with such deep spiritual roots so ultimately vain and self-serving? Of course not.
The quote "Do what thou wilt shall be the whole of the law" is but a portion of the Book of Law from Crowley, in which he reports to have written the laws of his practice, Thelema, as dictated to him by the spirit Aiwass. This spirit, Crowley believed, was his personal Holy Guardian Angel - a term somewhat synonymous with the term Higher Self. (For more information as to communing with one's Holy Guardian Angel, or Higher Self, explore the Abramelin Operation, or the Operations as dictated by the Golden Dawn). Through such dictates, the Holy Guardian Angel reportedly sought to teach a path a path to True Will.
This concept of True Will is the heart of the quote "Do what thou wilt," and thus expands its meaning far beyond the simple vanity of doing whatever one wishes. This Thelemic concept boils down to every individual possessing a driving motivation within their existence, and the Law of Thelema, "Do what thou wilt," seeks to instruct that each person to follow this driving motivation to find satisfaction and fulfillment in life.
Beyond this one Law, we find others describing each person as unique, with their own "True will" ("Every man and every woman is a star") which is just as sacred as your own. And in adhering to your own sacred True Will, it is just as important to refrain from interfering with another's True Will. No matter how much you might desire to do so, interfering with another's True Will would be interfering with sacred nature of who they are at their deepest core. It would be profane and violating to do so.
For, within another sacred law, we see "Love is the law, love under will." This means in turn that by attuning one's self to one's True Self, or True Will, we in turn find love and empowerment. And in seeking this, we seek the empowerment of others, and in so doing find union with every such being in the grace of Love.
So, as you can see, following the teachings of "Do what thou wilt" leaves no place in your magical and spiritual exploration for simply doing what you want, regardless of how it might impact another. It is not a philosophical scapegoat to simply do as you wish for personal gain, amusement, or revenge. If you truly seek to follow the Law, Do what thou wilt and seek the harmony, empowerment, and union found in exulting within one's True Will with others.