Sophie's World

by Jostein Gaarder

but the outer reality is essentially different from the reality of thought. Descartes now maintains that there are two different forms of reality – or two “substances.” One substance is thought, or the “mind,” the other is extension, or matter. The mind is purely conscious, it takes up no room in space and can therefore not be subdivided into smaller parts. Matter, however, is purely extension, it takes up room in space and can therefore always be subdivided into smaller and smaller parts – but it has no consciousness. Descartes maintained that both substances originate from God, because only God himself exists independently of anything else. But although both thought and extension come from God, the two substances have no contact with each other. Thought is quite independent of matter, and conversely, the material processes are quite independent of thought.’ ‘So he divided God’s creation into two.’