Is There A Non-Christian Reason To Be Against Contraception?

[FATNED]

12. On contraception, I got nothin'. On abortion...

I have two non-religious (indeed flat-out atheist) friends who are proudly raging liberals and yet oppose abortion. They are mightily conflicted about it but are opposed none the less. The crux of their opposition involves viability and technology; if a fetus could be viable outside the womb, it would be immoral to terminate the pregnancy. As viability gets pushed further and further by medical technology, the point at which it's wrong to abort gets pushed further back. If one day, a fetus is viable at two months, they argue it would be wrong to allow an abortion; since it's theoretically possible, the current two month fetus (even though not currently viable) must thus be life and it would be wrong to terminate it.

Okay, that is an extremely crude interpretation of their argument and it doesn't persuade me but yes, there are non-religious, indeed liberal opponents of abortion. I don't know all of the nuances they might argue (and I'm sure they'd be horrified at the botched and simple spin I put on their belief) so please don't unleash a torrent of arguments against their position and expect me to defend it...this is just my rough outline of their position.