In the same verse in which the Torah forbids a man from cohabiting with an animal, the Torah forbids a woman from cohabiting with an animal (Vayikra 18:23). Although intuitively we might have viewed these prohibitions as two aspects of a single Biblical command forbidding bestiality, the Rambam maintained that these are, in fact, two separate Torah commands. He drew proof from the Gemara’s discussion in the beginning of Masechet Keritut, where it lists the 36 prohibitions for which violators are liable to Karet. A man’s cohabiting with an animal and a woman’s cohabiting with an animal are listed as two separate commands. This prohibition applies in all places and in all times. If a female aged 12 or above cohabits with an animal, either in the normal manner of intercourse (“Ke’darkah”) or in the abnormal manner (“She’lo Ke’darkah”), and there are witnesses to the act, then both she and the animal are put to death through Sekila (stoning). If this was done by a girl between the ages of 3 and 12, then the animal is put to death, but the girl is not. However, the Sefer Ha’hinuch writes that she should be given some punishment for committing such an act. If the girl was younger than 3, than neither she nor the animal is put to death. If there were no witnesses to the act, then the violator is liable to Karet. If this violation was committed accidentally (meaning, if the woman was not aware that this is forbidden), then she must bring a Hatat (sin-offering), and the animal is not put to death. Intercourse with an animal falls under the category of “Arayot” (forbidden intimate relations) which is included among the seven Noachide laws that are binding upon all mankind, even gentiles. Thus, even non-Jews are bound by this prohibition. It should be noted that not all relationships forbidden by the Torah are forbidden for gentiles. The category of “Arayot” which is binding upon gentiles includes seven relationships: with one’s mother, with one’s father’s wife (even if she is not one’s mother), one’s sister from the same mother, another man’s wife, homosexual intercourse, and bestiality. A gentile is not forbidden from having relations with his sister with whom he shares a father but not a mother. The rule of “Ger She’nitgayer Ke’katan She’nolad Dameh” establishes that once a non-Jew converts and becomes a Jew, he is considered a newborn with respect to familial relationships. This means that he is no longer considered by Halacha to be related to his biological family members. On the level of Torah law, then, a convert is allowed to marry even his immediate family members – his mother and his sister – since he is not Halachically related to them. However, the Sages enacted that a convert may not marry any family member with whom marriage was forbidden before his conversion, so as not to appear as having fewer restrictions as a Jew than he did as a gentile. In order that a convert not give the impression as declining morally after converting, the Sages established a prohibition against marrying after conversion anyone whom he was not permitted to marry before his conversion. However, a convert is allowed to marry family members whom gentiles are permitted to marry, even if such a relationship is forbidden for Jews. And thus a convert is allowed to marry his half-sister with whom he shares only a father, as this relationship was allowed when he as a non-Jew.