In this doctoral dissertation I consider, and reject, the claim that recent varieties of non-reductive physicalism, particularly Donald Davidson's anomalous monism, are committed to a new kind of epiphenomenalism. Non-reductive physicalists identify each mental event with a physical event, and are thus entitled to the belief that mental events are causes, since the physical events with which they are held to be identical are causes. However, Jaegwon Kim, Ernest Sosa and others have argued that if we follow the non-reductive physicalist (...) in denying that mental features can be reduced to physical properties, then we must regard mental properties as being causally irrelevant to their bearers' effects, In short, the non-reductive physicalist is said to be committed to the belief that while there are mental causes, they do not cause their effects in virtue of being the types of mental state that they are. It is in this sense that non-reductive physicalists are thought to represent a new form of epiphenomenalism. After a brief survey of the history of epiphenomenalism, and its mutation into the contemporary strain that is believed to afflict non-reductive physicalism, 1 argue against the counterfactual criterion of the sort of causal relevance that we take mental features to enjoy. I then criticize the 'trope' response to the epiphenomenalist threat, and conclude that much of the current debate on this topic is premised on the mistaken belief that there is some variety of causal relevance that is not simply a brand of explanatory relevance. Once this is seen, it will seem much less plausible that mental properties are excluded from relevance to the phenomena of which we typically take them to be explanatory. (shrink)