It is a common argument that just because we don't fully understand something as complex as the human brain, that there must therefore be a transcendental universe of "soul stuff" that we can't measure that one day decided to take control of creatures sometime on the evolutionary line between the first bacteria and modern humans. I don't see the logic in this argument. If the brain merely "processes" consciousness and does not produce it, where IS consciousness? If it is not in this physical world, where is the evidence that something intangible can affect the physical world? Insofar as human consciousness is poorly understood, it seems to come from the brain and there is no compelling evidence that forces beyond the laws of physics, and the matter and energy inside the universe, are affecting our physical world. It is not unreasonable to demand extraordinary evidence for such an extraordinary claim as the eternal immortal soul theory.