Thelema

Thelema is a system of philosophical law and magic, developed by Aleister Crowley.

Several important Thelemic aspects and concepts are featured in the story of Toaru Majutsu no Index, and are involved in Aleister Crowley's plan.

Principles
In 1904, Crowley traveled to Egypt on a honeymoon with his wife, Rose Kelly. While there, she entered into some kind of connection with the Egyptian god Horus. To test this, Crowley subjected her to tests involving arcane and Qabalistic knowledge of Horus, which she apparently passed with flying colors. After performing a ritual, an entity known as Aiwass dictated to Crowley for an hour. Crowley titled the result The Book of the Law, and this book would become the central tenet of Crowley's new religion, Thelema ( for will).

The central belief behind both the Book of the Law and Thelema can be summed up in three sentences from the book:
 * "Do what thou wilt shall be the whole of the Law."
 * "Love is the law, love under will."
 * "There is no law beyond Do what thou wilt."

True Will is a central concept within Thelema. True Will originates from within the individual and could be referred to as their "true calling." In essence, it is the idea that a fully actualized person will act in accordance with their personal drive to act according to what they truly need to do. This is differentiated from a person merely doing what they want to and is not simply a call to hedonism. Instead, it is a person who surpasses the limitations of normal people by abandoning ideas of "right" and "wrong" as imposed by social norms and instead creating their own concept of morality that is true to themselves.

Uses of Thelema within the story

 * Aeons: Thelemic concept in which the history of humanity is divided into several different Aeons, named after Egyptian deities.
 * Aiwass refers to himself as a being from the Aeon of Horus during his encounter with Accelerator and refers to Accelerator's black wings as something from the Aeon of Osiris.
 * During his encounter with Fiamma of the Right, Aleister Crowley refers to how Fiamma used the wrong format in his plans, saying that if he'd based his plans in the Aeon of Horus rather Osiris he would have achieved a position similar to him.
 * Nephthys, who had laughed as Aleister named the Aeons, mentioned the concept to Kamijou Touma during her and Othinus's lecture on European magic and Africa.
 * Aiwass: An entity encountered by Aleister Crowley, from whom the Book of the Law originated.
 * Aiwass itself appears within the series, first appearing during the end of GROUP's confrontation with Shiokishi.
 * The Book of the Law: Also known as Liber AL vel Legis. The central sacred text of Thelema, written by Aleister Crowley and originating from Aiwass.
 * The Book of the Law is a coded grimoire, widely considered to be very dangerous by many on the Magic Side.