The name is derived from the Greek enkrateia, “self-control,” and was applied to various groups by Irenaeus, Clement of Alexandria, and Hippolytus. It was never used precisely, but included all those movements given to extremer ascetic practices. Their origins go back to Jewish Christianity, especially inasmuch as it was influenced by Qumran, to Gnosticism, and to those Docetic sects influenced by Greek philosophy. They tended to reject the use of wine (which, as among the Ebionites, would influence the celebration of the Lord's Supper) and of meat. Often marriage was repudiated. These groups were not necessarily heretical, but they were always in danger of going too far. Two of their leading figures were Tatian* (according to Jerome) and Julius Cassian, who expressed the ideals of the movement in his book Peri Eunouchias.