Perceptual Relativity – Perception is profoundly relativistic. Certain optical illusions can be used to help us understand concepts like opponent processing and multistable perception. What looks like dark grey next to white will look like light grey next to black, and indications of shadow and naturalistic form contribute also to perception. General and Special Relativity, in a very different way, assume perception-like definitions of physics. What is relativity if not some sensible relation? The main difference between the concept of inertial frames and multistable perception is that perception is private and presumed limited to living organisms, while physical groupings are public and considered universal to all material bodies. If that is true, it would make sense that both materialism and idealism (whether spiritual or information-theoretic) would mythologize presentation into fictional terms. Both material and ideal monisms, through their absolutist de-presentation of naive realism, subscribe to unacknowledged dualisms. Materialism and idealism do not explain each other, they only label each other illusions or emergent properties. Philosophy of Mind it seems, is itself a feature of perceptual relativity.