Beyond Mathematics and Geometry

Everything has an inside and an outside. We live in a world in which we mostly react to what is on the outside of things, and readily apparent, rather than what is on the inside, and often invisible to us. What is on the outside is the phenomenon, what is on the inside is the noumenon.
The distinction between what is phenomenal, and what is noumenal, is a major idea in the philosophical outlook of Kant, who pointed out that what things actually are is not only generally unknown to us, but is...