Abstract: If mental causal explanations are grounded in facts about physical causes and effects, and if there are no psychophysical laws, how can we avoid the conclusion that the mental is causally, and causally explanatorily, irrelevant? The chapter analyses the ways in which this objection has been raised against non-reductive monism in general, and Davidson's anomalous monism in particular. Then a conception of explanatory relevance for non-basic physical properties is set out: properties are candidates for explanatory relevance if they play a role in a simple model of causal action; it is intelligible how a property can be causally explanatorily relevant only if it supervenes on low-level physical properties; but such supervenience does not provide a self-standing condition of explanatory relevance. A parallel model is developed for the mental case, exploiting the intuitive model of rational action and appealing to supervenience. Anomalous monism is thereby defended against one objection; but, it is argued, this defence challenges the original motivation for thinking that mental events must be physical events.

Keywords: anomalous monism, causal explanation, causal relevance, causation, explanatory relevance, non-reductive monism, supervenience,