Θέλημα in Greek, means Will.
Thelema is the name of the philosophical school and religious matrix established in 1904 with the writing of Liber AL vel Legis (The Book of the Law) by Aleister Crowley (1875-1947). The Law is summed up in two phrases from the Book:
The central goal of a Thelemite (as adherents refer to themselves) is to discover and perform his or her True Will, which is generally defined as the innermost Nature or proper life course of the individual. The techniques used to achieve this goal fall under the heading of Magick.
There are also strong political, ethical, aesthetic, and cultural aspects to Thelema. Although there is no strict literal doctrine concerning these matters, Aleister Crowley wrote many articles and essays regarding his ideas about the proper behavior of individual Thelemites and for an ideal Thelemic society. These ideas have continued to develop into modern times. However, the primary themes involve personal freedom, a recognition that men and women have an inherent divine nature, and that Love is the basis of the Great Work.