ABSTRACT
Humanity has thousands of years of practice in trying to understand the world around us. Every culture comes to an understanding that certain things matter and others do not. We pay attention to the things that matter and build them into models of our external world. At various times and places, we have believed that things happen because of the actions of gods, demons, four (or ve) elements, four humors, Qi, chemical or mechanical actions, rational decision making, invisible economic hands, historical forces, heredity, environment, predestination, or sheer chance.
