Immaterial concepts are abstracted from the physical world, but they in themselves are immaterial. You can hide this plain fact in all the mumbo-jumbo you want,

Immaterial concepts are abstracted from the physical world, but they in themselves are immaterial. You can hide this plain fact in all the mumbo-jumbo you want, but it remains a fact. Even a simple concept, like the definition of a circle, is not material in itself.