Chaos argument

Chaos argument is the position that determinism is an idealistic mathematical construction whose mapping onto reality is untestable in the real world and that this is an essential property for free will to exist in our universe.

The chaos argument asserts that given any description of position and momentum (of all particles in the universe) approaching completeness, long-term prediction is impossible, because variances from completeness multiply over even short periods of time.

Due to the Uncertainty Principle of quantum mechanics, we as observers can never have access to a complete description and therefore can never close the debate on free will versus determism.

Also, the electrodynamics of the human brain are chaotic in nature; accordingly there is also no way to prove, in the event that free will does exist in the universe, whether the human has none.