We tend to think that our concepts are stable in the sense that, whilst their extensions may vary across distinct epistemic scenarios, the reference-fixing conditions by which we discover these extensions remain fixed. This paper challenges this orthodoxy. In particular, it aims to motivate the position that some concepts are unstable in that their reference-fixing conditions themselves vary across distinct epistemic scenarios. Furthermore, it aims to draw out the implications such instability has for epistemic possibility and apriority. I shall argue (...) that when unstable concepts are concerned epistemic space will be widened, which in turn will restrict our a priori knowledge; and in ways that might be salient to solving certain familiar philosophical problems. (shrink)

In this paper, we make a case for the disjunctive view of phenomenal consciousness: consciousness is essentially disjunctive in being either physical or non-physical in the sense that it has both physical and non-physical possible instances. We motivate this view by showing that it undermines two well-known conceivability arguments in philosophy of mind: the zombie argument for anti-physicalism, and the anti-zombie argument for physicalism. By appealing to the disjunctive view, we argue that two hitherto unquestioned premises of these arguments are (...) false. Furthermore, making use of the resources of this view, we formulate distinct forms of both physicalism and anti-physicalism. On these formulations, it is easy to see how physicalists and anti-physicalists can accommodate the modal intuitions of their opponents regarding zombies and anti-zombies. We conclude that these formulations of physicalism and anti-physicalism are superior to their more traditional counterparts. (shrink)