Russellian Monism and Mental Causation

Russellian monism is a promising theory of consciousness that attempts to capture the strengths of both physicalism and dualism while avoiding their weaknesses. I begin by showing that the Russellian monist’s chief anti-physicalist rival, emergentism, is unable to give an adequate solution to the exclusion problem. Specifically, they fall prey to what I call “the opacity problem.” That is, because the emergentist is committed to there being both a sufficient physical cause and a sufficient mental cause for our actions, it is unclear what difference the mental cause is making in bringing about the effect. This is because, for the physical cause to truly be a sufficient cause, it must be sufficient to bring about the effect as it occurred. This distinguishes mental overdetermination from non-problematic kinds of overdetermination (like double rock throwing cases). I then show how the constitutive Russellian monist is able to avoid the exclusion problem, while the emergent Russellian monist faces similar opacity problems to emergentism. Finally, I give an account of how the constitutive Russellian monist can give a response to the strongest objection against—the subject-summing problem. I argue that we only have translucent access to our conscious states—that is, only part of the essential nature of the state is revealed to us through introspection. I then argue that we have reason to think that part of the essential nature of the conscious state not revealed to us is involved in subject-summing.