D. Gene Witmer

The manifestability argument presented by Papineau and Loewer turns on the premise that nonphysical properties are capable of making a difference to physical conditions. From this and the completeness of physics a strenuous supervenience conclusion is supposed to follow. I argue that the plausible version of this premise implies a weaker supervenience thesis only, one that is too weak to be of any use for a physicalist. There is a more contentious premise one might use to deduce the needed conclusion, but that more contentious premise has no empirical support

Physicalists motivate their position by posing a problem for the opposition: given the causal completeness of physics and the impact of the mental (or, more broadly, the seemingly nonphysical) on the physical, antiphysicalism implies that causal overdetermination is rampant. This argument is, however, equivocal in its use of 'physical'. As Scott Sturgeon has recently argued, if 'physical' means that which is the object of physical theory, completeness is plausible, but the further claim that the mental has a causal impact on the physical is no longer so evident. In this paper I assess the damage due to the ambiguity of 'physical' and provide a repair to the overdetermination strategy.

In his 'The Disorder of Things' John Dupré presents an objection to reductionism which I call the 'anti-essentialist objection': it is that reductionism requires essentialism, and essentialism is false. I unpack the objection and assess its cogency. Once the objection is clearly in view, it is likely to appeal to those who think conceptual analysis a bankrupt project. I offer on behalf of the reductionist two strategies for responding, one which seeks to rehabilitate conceptual analysis and one (more concessive) which avoids commitment to any such analysis