Block's "evictionism" and the NAP

As I've written before, abortion is an unsettled issue among libertarians. There's been a very good debate between Walter Block and Jakub Wisniewski on Block's theory of "evictionism", and whether or not it's compatible with what libertarians call the Non-aggression Principle (NAP). I thought I'd share the links for your reading pleasure:

Block's original case for evictionism - http://www.walterblock.com/wp-content/uploads/publications/block-whitehead_abortion-2005.pdf

Wisniewski's rebuttal - http://libertarianpapers.org/articles/2010/lp-2-16.pdf

Block's rejoinder to Wisniewski - http://libertarianpapers.org/articles/2010/lp-2-32.pdf

Wisniewski's rejoinder to Block - http://libertarianpapers.org/articles/2010/lp-2-37.pdf

I think at this point I'm with Wisniewski. I like his throwing "proportionality" in there. If eviction results in death, and with abortion it does, then that isn't proportionate to the baby having trespassed the mother's body. It would be a disproportionate result of righting a wrong (trespass). I still feel Block's theory of evictionism has practical value.

UPDATE August/2011: There has been another round to this debate. Here are the links:

Block's response to Wisniewski, Round 2 - http://libertarianpapers.org/2011/4-block-response-to-wisniewski-on-abortion-round-two/
Wisniewski's response to Block, Round 3 - http://libertarianpapers.org/2011/6-winiewski-response-to-block-on-abortion-round-three/

This has been a very thoughtful debate. On principle, I'm with Wisniewski, but in practice, I'm with Block. I think his theory of evictionism has the best chance of making progress on this critical issue. I believe in time abortion will be unnecessary.