Abortion compounds the tragedy of incest by forcing the mother to live with the fact that she's murdered her unborn child.
You could point your friend to these testimonies of post-abortive women.
He wouldn't read them. I sent him a technical article on computer modeling which explained how designing accurate climate models is essentially not possible. Got a nasty one liner back in all caps. Which is a reliable indicator that I have struck a nerve. The "truth" nerve, the one that really hurts.