Frank Jackson has argued that only if we have a priori knowledge of the extension-fixers for many of our terms can we vindicate the methodological practice of relying on intuitions to decide between philosophical theories. While there has been much discussion of Jackson’s claim that we have such knowledge, there has been comparatively little discussion of this most powerful argument for that claim. Here I defend an alternative explanation of our intuitions about possible cases, one that does not rely on (...) a priori extension-fixers. This alternative explanation provides a vindication of our reliance on intuitions, while blocking Jackson’s abductive argument for a priori semantic knowledge. In brief, I argue that we should regard our armchair intuitions as providing an important, a priori source of evidence for hypotheses about the contents of our implicit referential policies with regard to our terms. But all such hypotheses have a potential falsifier that is only discoverable empirically. In other words, gold-standard evidence for such hypotheses is always empirical. (shrink)

Perhaps more controversial than whether physicalism is true is what exactly would have to be true for physicalism to be true. Everyone agrees that, intuitively at least, physicalism is the thesis that there is nothing over and above the physical. The disagreements arise in how to get beyond this intuitive formulation. Until about ten years ago, participants in this debate were concerned primarily with answering two questions. First, what is it for a property, kind, relation, or individual to be a (...) physical one? (shrink)

2. The Contingency and A posteriority Constraint: A formulation of the thesis must make physicalism come out contingent and a posteriori. First, physicalism is a contingent truth, if it is a truth. This means that physicalism could have been false, i.e. there are counterfactual worlds in which physicalism is false, for example, counterfactual worlds in which there are miracle -performing angels.[9] Moreover, if physicalism is true, our knowledge of its truth is a posteriori. This is to say that there are (...) ways the world could turn out to be such that physicalism is false. For example, if there are miracle -performing angels, then physicalism is false. So there are worlds considered as actual in which physicalism is false.[10] For short, call this ‘the a posteriority constraint’.[11]. (shrink)

What would be sufficient to show of some apparently higher-level property that it is 'nothing over and above' some complex configuration of more basic properties? This paper defends a new method for justifying reductions by demonstrating its comparative advantages over two methods recently defended in the literature. Unlike its rivals, what I'll call "the semantic method" makes a reduction's truth epistemically transparent without relying on conceptual analyses.

One strategy for blocking Chalmers's overall case against physicalism has been to deny his claim that showing that phenomenal properties are in some sense physical requires an a priori entailment of the phenomenal truths from the physical ones. Here I avoid this well-trodden ground and argue instead that an a priori entailment of the phenomenal truths from the physical ones does not require an analysis in the Jackson/Chalmers sense. This is to sever the dualist's link between conceptual analysis and a (...) priori entailment by showing that the lack of the former does not imply the absence of the latter. Moreover, given the role of the argument from conceptual analysis in Chalmers's overall case for dualism, undermining that argument effectively undermines that case as a whole in a way that, I'll argue, undermining the conceivability arguments as stand-alone arguments does not. (shrink)