Many have argued that there is something that is a priori about all necessary truths, including a posteriori necessities. According to a particularly popular claim of this kind, one can know a priori whether a sentence is G-necessary, i.e. whether it is either necessarily true or necessarily false. In this paper, I identify the most plausible version of this claim and I argue that it fails. My discussion also reveals, and depends upon, an important feature of putative natural kind terms (...) that has been widely overlooked. I conclude by outlining a proposal of what is really a priori about necessities. (shrink)

Kant famously argued that, from experience, we can only learn how something actually is, but not that it must be so. In this paper, I defend an improved version of Kant's argument for the existence of a priori knowledge, the Modal Argument , against recent objections by Casullo and Kitcher. For the sake of the argument, I concede Casullo's claim that we may know certain counterfactuals in an empirical way and thereby gain epistemic access to some nearby, nomologically possible worlds. (...) But I maintain that our beliefs about metaphysical necessities still cannot be justified empirically. Furthermore, I reject Casullo's deflationary thesis about the significance of such justification. Kitcher's most troublesome objection is that we can gain any modal justification whatsoever through testimony , i.e. in an experiential way. This can be countered by distinguishing between productive sources of justification, like perception, and merely reproductive sources, like testimony. Thus, some productive a priori source will always be needed somewhere. (shrink)

G. E. Moore argues that goodness is an intrinsic non-natural property that supervenes irreducibly on the intrinsic natural properties of its bearers. Accordingly, it is often supposed that “Moorean” supervenience is incompatible with physicalism, a naturalistic thesis. In this paper I argue that Moorean supervenience is not in itself incompatible with physicalism, Moore’s ethical non-naturalism notwithstanding. Understanding why will help us to better appreciate the full range of resources available to physicalists.

The view that contradictions cannot be true has been part of accepted philosophical theory since at least the time of Aristotle. In this regard, it is almost unique in the history of philosophy. Only in the last forty years has the view been systematically challenged with the advent of dialetheism. Since Graham Priest introduced dialetheism as a solution to certain self-referential paradoxes, the possibility of true contradictions has been a live issue in the philosophy of logic. Yet, despite the arguments (...) advanced by dialetheists, many logicians and philosophers still hold the opinion that contradictions cannot be true. -/- Rather than advocating the truth of certain contradictions, this thesis offers a different challenge to the classical logician. By showing that it can be philosophically coherent to propose that true contradictions are metaphysically possible, the thesis suggests that the classical logician must do more than she currently has to justify her confidence in the impossibility of true contradictions. Simply fighting off the dialetheist’s putative examples of true contradictions at the actual world isn’t enough to justify the classical logician’s conclusion that true contradictions are impossible. -/- To aid the thesis dialectically, we introduce a new position, absolutism, which hypothesises that it’s metaphysically possible for at least one contradiction to be true, contrasting with the dialetheic hypothesis that some contradictions are true in the actual world. We demonstrate that absolutism can be given a philosophically coherent interpretation, an appropriate logic, and that certain criticisms are completely toothless against absolutism. The challenge put to the classical logician is then: On what logical or philosophical grounds can we rule out the metaphysical possibility of true contradictions? (shrink)

This paper examines the legitimacy of two common methodologies within philosophy: thought experiments and conceptual analysis. In particular, I examine the uses to which these two methodologies have been put within modal epistemology. I argue that, although both methods can be used to reveal conditional essentialist claims (e.g. necessarily: if x is water, then x is H20), neither can be used to reveal the de re essentialists claims (e.g. x is water and x is essentially H20) they’re often taken to (...) reveal. (shrink)

In this paper, I reevaluate Kripke’s arguments for the necessary a posteriori contra a Kantian pure modal rationalism according to which modal cognition is a priori. I argue that Kripke’s critique of Kant suggests an impure but nevertheless ambitious modal rationalism according to which the basis of modal cognition remains a priori. I then argue that Kripke’s critique of pure modal rationalism does not go deep enough. More specifically, I argue that certain conditional modal judgments, which Kripke regards as a (...) priori, are, in fact, a posteriori. An example is the conditional modal judgment that if gold is a metal, then it is necessary that gold is a metal (if gold exists). However, Chalmers has developed a general frontloading strategy for turning a posteriori conditionals into a priori ones. So, I consider whether the frontloading strategy may be applied in a development of a modest modal rationalist account of the necessary a posteriori. Although the frontloading strategy is attractive for the modal rationalist, I argue for a twofold conclusion. First, I conclude that a posteriori conditionals constitute a serious and unanswered challenge to modal rationalists. Second, I conclude that the frontloading strategy does not by itself provide a response to this challenge and that substantiating the strategy is problematic. (shrink)