In _Road to Reality_, Roger Penrose has a diagram that illustrates the Platonic world of mathematics fully encompassing the physical world, and the physical wor

In _Road to Reality_, Roger Penrose has a diagram that illustrates the Platonic world of mathematics fully encompassing the physical world, and the physical world fully encompassing the mental world (since minds are physical), and the mental world fully encompassing the Platonic world of mathematics. Although each encompasses the other in its entirety, each depends only on a small part of its predecessor. Penrose says "...the Platonic world may be the most primitive of these three, since mathematics is a kind of necessity, virtually conjuring its very self into existence through logic alone."