This is an intresting read even if TMI...
What exactly was the sin of Onan?
Dear Straight Dope:
I read your two-part report on the curse of Noah/Canaan/Ham et al and found it very illuminating. Another enigmatic story in the Bible is the story of Onan. This one has been used to prove that masturbation is evil and punishable by death, so much so that the words masturbation and onanism are synonymous. I've read that story over and over, and I'm not sure where people get the masturbation connection. On the surface it seems to me that Onan married his deceased brother's wife, according to Jewish law, but he did not love her. However, instead of putting her away and leaving her alone, he had sex with her, but didn't want to have children with her, so he pulled and prayed, thus "spilling his seed on the ground." My take on it is this: God struck Onan down because he was a rapist who abused his wife, not because he liked to yank his doodle. Or am I just twisting the Bible for my own purposes to alleviate my guilt about spending inordinate amounts of time in the bathroom? Just sign me . . .
— Gilbert O'Sullivan, Cleveland, Ohio
You're right, Onanism and masturbation have been used synonymously in Western cultures, but they probably shouldn't be. We'll start with a look at the story as told in Genesis 38:6-10, then show how it was used to justify attitudes towards sex in Judeo-Christian religions.
In the biblical text, Judah, the son of Jacob (called Israel) has three sons, the two of importance to this story being Er and Onan:
Judah got a wife for Er, his first-born; her name was Tamar. But Er, Judah's first born, was displeasing to the Lord and the Lord took his life. Then Judah said to Onan, "Join with your brother's wife and do your duty by her as a brother-in-law, and provide offspring for your brother." But Onan, knowing that the seed would not count as his, let it go to waste whenever he joined with his brother's wife, so as not to provide offspring for his brother. What he did was displeasing to the Lord, and He took his life also.
First, the simple explanation of the text.
The death of Er (see note 1 below) without a son makes Onan subject to what is called the levirate law (note 2). Although the law isn't specifically...