Firstly, IAAL. Secondly, I'm working on a crypto-currency that's designed for the automatic enforcement of contracts. Thirdly, I was (am) an engineer, and always saw writing contracts as akin to coding.
I see no way to automatically enforce contracts without a third party intermediary, which sort of goes against the spirit of the coin. Be that party a crowd-sourced wisdom, an impartial oracle, or whatever. Is there another way?