Abstract

This dissertation focuses on the question of whether or not we can adjudicate between competing criteria for what exists. A criterion for what exists provides the necessary and sufficient conditions for what sorts of entities are real. It tells us which property, or which set of properties, an entity must possess to count as existing. Example: an entity exists if and only if it has causal powers. ;My thesis, in this project, is that we are not in a position to adjudicate between competing criteria for what exists. A criterion for what exists is philosophical bedrock, and it isn't possible for us to slide any justification underneath it. ;The first chapters of the dissertation focus on four candidate criteria for what exists: the causal criterion , the criterion of causal explanation , the criterion of best explanation , and the criterion of indispensability . My purpose is not to defend any of these criteria, nor to work out what exactly falls under them, but to get a good statement of each criterion, so that we have a set of possible candidates to adjudicate between. ;I then move to defend my main thesis. To this end, I examine four groups of arguments that might be used to defend a criterion for what exists: arguments from Quine's criterion, epistemic arguments, inductive arguments, and metaphysical arguments. I then try to show that each type of argument has to fail