Going back to worms, they have a certain awareness, for example, of light, different types of soil, they can move in a certain direction, and avoid attack. But Alan is saying that brains can't produce awareness, only souls, so how does the worm do this?
I suppose Alan is saying that humans have a special awareness, quite different from worms' awareness. But we might surmise that as nervous systems (and brains) evolve, so does awareness? We can think of the eye evolving, and thus, the nature of vision.