[Krsqk]

Perhaps this would be a better argument against prophecy. As complex systems grow in complexity they inevitably qualitatively change, thus nullifying existing predictions. Determinism is a little more annoying since it relies on supernatural influence (whether it be a god, a set of laws, etc.) and so is exempt from most rational arguments (it can always claim omniscience).

Although, that would make prophecy under a free-will system all the more remarkable. BTW, I don't see the existence of the supernatural as contradictory to the operation of free will; they operate in different spheres (although supernatural could override/negate the effects of free will if necessary).