Theory of consciousness judged by external and internal constraints

A theory of consciousness should be judged by two constraints: an external constraint of fitting the empirical data, and an internal constraint of minimizing or eliminating explanatory gaps—places where the theory jumps from one set of facts to another with no account of how; materialism, while fitting data, has an enormous internal explanatory gap between quantitative properties and qualitative consciousness, whereas Russell-Eddington panpsychism makes progress by identifying conscious states as the intrinsic nature of physical states.