A few months ago I reread parts of The Ethics, Spinoza?s attempt to derive the laws of appropriate human behavior from first principles. Spinoza?s ideal style of theorizing was that of Euclid?s geometry. But, though his approach to morals and the purpose of life follows Euclid in style, his theory rests on its own two feet.

When you try to understand the laws that may drive the world, you can use models or theories. Models are metaphors. They compare something you don?t understand too well to something you understand better, in order to add insight. Calling a computer an electronic brain, for example, is a metaphor that once cast light on the function of computers. Nevertheless, a computer is not an electronic brain, though it may be a little like it. Conversely, the brain is not a computer, though it may be a little like it too. We do our best to explain the thus-far incomprehensible by describing it in terms or the things we already comprehend. Models, like metaphors, take the properties of something rich and project them onto something strange.