Leviticus 18 contains an extensive list of sexual prohibitions and taboos. From this list, commentators addressing the issue of artificial insemination generally must deal with the prohibition contained in Lev. 18:20 "And thou shalt not implant thy seed into thy neighbor's wife, to defile thyself with her." The interpretation of this verse defines the opposing viewpoints of authorities. Some focus on the implanting of the seed as the adulterous act, considering it adultery to implant semen even without sexual intercourse taking place.4 others insist that without the necessary element of carnal relations adultery has not occurred.5 As we shall later see, even the authorities within these two broad schools of thought are somewhat at odds with each other.
The use of Lev. 18 as the basis for Jewish law is not wholly accepted. Some question whether exegesis of the narrative portions of the Bible qualifies as a legitimate source of law according to present day Halakhah. As one researcher noted, "This exegesis constituted an important source of the law, particularly in the Tannaitic period, but after the redaction of the Talmud, and specifically from the middle of the Gaonic period, it almost totally ceased to serve as a legal source."6 However, halakhic writings take a critical view of decisions based on exegesis from th