Is Weak Supplementation analytic?

Mereological principles are often controversial; perhaps the most stark contrast is between those who claim that Weak Supplementation is analytic—constitutive of our notion of proper parthood—and those who argue that the principle is simply false, and subject to many counterexamples. The aim of this paper is to diagnose the source of this dispute. I’ll suggest that the dispute has arisen by participants failing to be sensitive to two different conceptions of proper parthood: the outstripping conception and the non-identity conception. I’ll argue that the outstripping conception (together with a specific set of definitions for other mereological notions), can deliver the analyticity of Weak Supplementation on at least one sense of ‘analyticity’. I’ll also suggest that the non-identity conception cannot do so independently of considerations to do with mereological extensionality

Parfit's and Scanlon's Non-Metaphysical Moral Realism as Alethic Pluralism

Thomas Scanlon and Derek Parfit have recently defended a meta-ethical view that is supposed to satisfy our realistic intuitions about morality, without the metaphysical implications that many find hard to accept in other realist views. Both philosophers argue that truths in the normative domain do not have ontological implications, while truths in the scientific domain presuppose a metaphysical reality. What distinguishes Scanlon and Parfit’s approach from other realistic meta-ethical theories is that they maintain that normative entities exist in a way that is different from (some) non-normative entities. Moreover, they think that the way normative entities exist helps to answer the metaphysical worries that are often thought to plague non-naturalism. To make sense of this idea, I develop their view as a version of alethic pluralism: the position that there is more than one truth property. I argue, however, that when their view is developed in this way it fails to satisfy our realistic intuitions about morality. This shows that on a plausible and initially promising reading of what it takes for a normative entity to exist in a way that is different from non-normative entities, Parfit’s and Scanlon’s non-metaphysical moral realism fails to be more realistic than contemporary versions of anti-realism