Shepherd, John J. “Panpsychism and Parsimony.” Process Studies 4, no.1 (Spring 1974): 3-10.  

Abstract

An argument for Whiteheadian panpsychism is that by Occam’s razor it is preferable to dualist systems. This argument faces the obverse difficulty of materialism. The latter must urge that mental images are mere appearances rather than in mental space; the former should urge that extended physical entities are mere appearances since there is only the mental space formed by occasions of experience. Incompatible natures of mental and physical extension entail the falsity of this panpsychism.