Interpreting the perennially perplexing sexual regulations of Leviticus 1820 in a radically new way, Calum M. Carmichael offers a key to understanding not only the texts themselves but also the nature of lawgiving throughout the Pentateuch. Carmichael identifies and offers solutions to puzzles such as why the lawgiver explicitly prohibits certain obviously wrongful acts (such as a son's intercourse with a mother), but not others (such as full brother with sister), why he censures children instead of adults in taboo couplings, and why rules not connected with incest (prohibiting Molech worship and intercourse with a menstruating woman) are included with rules about incest. Reading these laws against the events described in Genesis, Carmichael asserts that the conduct of biblical ancestors--from Lot's fathering of children with his daughters to Abraham's marriage to his half-sister--was the inspiration for the incest rules in Leviticus. He maintains that the Levitical codes cannot be separated from their larger narrative framework. Invaluable for biblical interpretation, Carmichael's approach also has broader applications, clarifying as it does the tendency of lawmakers to formulate general rules in response not to obvious but rather to idiosyncratic problems.