 The latter part of the twelfth through the fourteenth centuries, however, saw a sharp rise in intolerance towards homosexual sex, alongside persecution of Jews, Muslims, heretics, and others. While the causes of this are somewhat unclear, it is likely that increased class conflict alongside the Gregorian reform movement in the Catholic Church were two important factors. The Church itself started to appeal to a conception of “nature” as the standard of morality, and drew it in such a way so as to forbid homosexual sex (as well as extramarital sex, nonprocreative sex within marriage, and often masturbation). For example, the first ecumenical council to condemn homosexual sex, Lateran III of 1179, stated “Whoever shall be found to have committed that incontinence which is against nature” shall be punished, the severity of which depended upon whether the transgressor was a cleric or layperson (quoted in Boswell, 1980, 277). This appeal to natural law (discussed below) became very influential in the Western tradition. An important point to note, however, is that the key category here is the ‘sodomite,’ which differs from the contemporary idea of ‘homosexual’. A sodomite was understood as act-defined, rather than as a type of person. Someone who had desires to engage in sodomy, yet did not act upon them, was not a sodomite. Also, persons who engaged in heterosexual sodomy were also sodomites. There are reports of persons being burned to death or beheaded for sodomy with a spouse (Greenberg, 1988, 277). Finally, a person who had engaged in sodomy, yet who had repented of his sin and vowed to never do it again, was no longer a sodomite. The gender of one’s partner is again not of decisive importance, although some medieval theologians single out same-sex sodomy as the worst type of sexual crime (Crompton, 2003, ch.6).