On the Alleged Knowledge of Metaphysical Modality

Many metaphysical controversies can be understood as debates over whether some alleged entities are metaphysically possible. (Examples: Are zombies possible? Is atomless gunk possible? Are extended simples possible? etc.) No doubt, with regard to these matters, we may have opinions or theories, commonsensical or sophisticated. But do we have knowledge of them? Can we really know that something is metaphysically possible, and if so, how? Several different answers have been offered in the literature, intending to illustrate how we may have knowledge of metaphysical modality. In this paper, I concentrate on a proposal by Timothy Williamson (2007). On this account, our alleged knowledge of metaphysical modality is justified by and grounded in our capacity to handle ordinary mundane counterfactual conditionals. However, I argue that Williamson's account fails, mainly because the modality involved in ordinary mundane counterfactuals is causal, and thus our capacity to handle them still falls short of giving us any knowledge of metaphysical modality. In the end of the paper, I also provide my own answer to the question. My answer is a sceptical one: we do not really have knowledge of metaphysical modality. But such ignorance is harmless, or so I argue.