The biblical penalty for not giving your brother’s widow children was public humiliation, not death (Deut. 25:7–10). But Onan received death as punishment for his crime. This means his crime was more than simply not fulfilling the duty of a brother-in-law. He lost his life because he violated natural law, as Jewish and Christian commentators have always understood. For this reason, certain forms of contraception have historically been known as “Onanism,” after the man who practiced it, just as homosexuality has historically been known as “Sodomy,” after the men of Sodom, who practiced that vice (cf. Gen. 19).