The following dissertation is an examination of arguments against physicalism. Physicalism is a thesis in the philosophy of mind that is constituted by two central claims: (1) the ontological claim that everything that exists is ontologically physical and that human beings are among such things; (2) the explanatory claim that all facts about human beings and all explanations of their behaviour are dependent on and determined by physical facts and explanations. It has frequently been asserted that there are properties that escape capture in physicalist accounts of human behaviour, thereby undermining (2). Such properties are usually thought to be lacking causal powers, and hence have been called "epiphenomenal." The epiphenomenalist objections have long been thought to represent a serious obstacle to physicalism. My aim is to show that the objections that are motivated by epiphenomena} properties are unconvincing. My discussion proceeds in two stages. In the first stage I examine the epiphenomenalist objections in detail and show that in their most persuasive forms they demonstrate that physicalism has certain explanatory inadequacies. The critics of physicalism believe that these shortcomings lead to the denial of the explanatory completeness of physicalism, and I try to make their case as charitably as I can. In the second stage of the argument I invoke the relation of psycho-physical supervenience and show that the desired conclusion does not follow, even if we admit that physicalism has certain explanatory failings. The overall conclusion ofthis dissertation is that the epiphenomenalist objections to physicalism are completely undermined and hence that properties which were thought to be epiphenomena! do not represent a serious obstacle to physicalisrn as was previously thought. My intention is that this discussion push forward work in the philosophy of mind and point the way to a more adequate articulation of physicalism. / Thesis / Doctor of Philosophy (PhD)