I'm not claiming that we "need" determinism, but I am saying that I
believe it is most likely the way things are, whether or not we "need" it or
want it, though of course I can't prove this. From the physics ("bottoms
up") point of view, deterministic unitary evolution of the wavefunction or
quantum state seems to be consistent with all experiments and much simpler
(IMHO) than unitary evolution occasionally interrupted by random collapses
of the wavefunction. From the theological ("top down") point of view, total
determination by one single Creator God also seems simpler (IMHO) than
partial determination by other entities (persons within the universe, random
fluctuations, etc.)
It isn't that ultimate causes other than God would necessarily
infringe upon God's omniscience, but I believe it would infringe upon the
idea that He has created everything (apart from Himself). If God is the
Creator of everything, then no matter how interesting or desirable He might
find "novelty through genuine chance" or "genuine freedom to nature" or
incompatibilist free will in humans, I believe it would be logically
impossible for this to occur, since the only entities outside of God that
could exist would be entities He makes, and He can't make them independent
of how He makes them. He could limit Himself not to create something, but
if nothing exists apart from what He creates, one cannot also coherently
imagine that He limits Himself not to create and thereby totally determine
something that actually exists (e.g., a human decision that is humanly
considered to be free).
We can enjoy interacting with entities (e.g., people and things) we
did not make, and they can have genuine novelty or freedom relative to us,
but God does not have this luxury of finding entities outside Himself that
He did not make; if they are to exist, He must make them, and then they are
not free from His fashioning and determination.
Of course, one could postulate that the entity we traditionally call
"God" is just part of a larger set of entities that are ultimate causes for
everything, and allow genuine chance and/or genuine (incompatibilist) free
will of humans (for example) to be other ultimate causes besides "God."
This view might be logically coherent, but I don't find this view of a more
complicated set of ultimate causes to be either plausible or Biblical. It
smacks too much of dualism or polytheism and says that "God" is not totally
sovereign over everything.
Don Page