  Mach was a naturalist and a monist, as well as an anti-materialist in the sense of being an anti-mechanist. The connection between naturalism and materialism is an important one for Mach. Naturalism, in its simplest sense, is the doctrine that there is nothing beyond nature, not even the organic or mental, and evolution is thus generally a crucial component of it. The materialism of the mechanical philosophy is the further view that this nature consists of matter in motion, and in particular that psychic phenomena can be reduced to matter in motion. Although materialism can make as much use of evolution as naturalism, Mach’s nineteenth century evolutionary views influenced his anti-materialism. Whereas mechanistic materialism views nature as an organized system of billiard balls, Mach’s evolutionary perspective viewed nature as a dynamic process.