In this dissertation, I evaluate whether conceivability can be regarded as an epistemic guide to possibility.

In this paper, I argue that, if transcendental arguments are to proceed from premises that are acceptable to the skeptic, the Transcendental Premise, according to which “X is a metaphysically necessary condition for the possibility of Y,” must be grounded in considerations of conceivability and possibility. More explicitly, the Transcendental Premise is based on what Szabó Gendler and Hawthorne call the “conceivability-possibility move.” This “inconceivability-impossibility” move, however, is a problematic argumentative move when advancing transcendental arguments for the following reasons. First, (...) from “S cannot conceive of P” it doesn’t necessarily follow that P is inconceivable. Second, from “P is inconceivable” it doesn’t necessarily follow that P is metaphysically impossible. Third, rather than block skeptical doubts, the conceivability-possibility move introduces skeptical doubts. For these reasons, transcendental arguments fail to deliver on their promise to overcome skeptical doubts. (shrink)

Howell Pacific Philosophical Quarterly, 89, 348–358 and Mizrahi and Morrow Ratio, 28, 1–13 offer a group of reductio arguments to rebut the CP thesis, i.e., the hypothesis that ideal conceivability entails possibility. Each of them has a conceivability premise: it is ideally conceivable that CP is false. According to the same CP, one can infer that CP’s being false is possible, from which it follows that CP is false. In other words, CP is shown to be self-defeating and therefore false (...) if any of these reductio arguments is proved sound. In this paper, I aim to disprove these arguments. I first show that neither Howell nor Mizrahi & Morrow provide adequate justification for their conceivability premises. I go on to argue that these reductio arguments face a dilemma: either their conceivability premises cannot be adequately justified, or they are redundant. Finally, I argue that, although this dilemma resists the reductio arguments against CP, on the other hand, it also reveals that CP lacks epistemic fruitfulness: it is of no practical use in the realm of apriority as well as necessity. (shrink)