Material can be put equal to energy, so then, what is energy made of? Energy is made of force carrying particles that traverse the spatial medium at the speed of light in wave form.
So then, what are the particles and waves made of? Archetypes, of, possibility, intention, thoughts, mind, or, consciousness - nothing. Zero volume, reality is an illusion, a dream, but a very persistent one as Mr. Albert Einstein said; also a bit more organized and substantial as well.
The Wall