One of the most widely-discussed arguments against physcialism appeals to the conceivability of zombies, being which are physically or functionally identical to humans but which have no conscious experiences. Philip Goff : 119–139, 2010; Consci Cognit 21: 742–746, 2012a; in Sprevak M, Kallestrup J New waves in philosophy of mind. Palgrave, 2014) has recently presented a number of different anti-physicalist arguments appealing to the conceivability of ghosts, entities whose nature is exhausted by their being conscious. If ghosts are conceivable, this (...) would rule out a priori physicalism. If the conceivability of ghosts entails that they are metaphysically possible, then this forms the basis for arguments against a posteriori physicalism. Drawing on work on conceivability by Peter Kung :620–663, 2010, Noûs 50: 90–120, 2016) and my own discussion of arguments which appeal to the conceivability of zombies Consciousness and the ontology of properties. Routledge, New York, 2019), I shall argue that ghosts are conceivable, but that what allows us to conceive of them undermines the belief that conceivability is a reliable guide to possibility. While this does not undermine Goff’s argument against a priori phyiscalism, it suggests that a posteriori physicalists need not be haunted by ghosts. (shrink)