The gist of the many-subjects argument is that, given physicalism, it’s hard to avoid the absurd result that there are many conscious subjects in your vicinity with more-or-less the same experiences as you. The most promising ways of avoiding this result have a consequence almost as bad: that there are many things in your vicinity that are in a state only trivially different from being conscious, a state with similar normative significance. This paper clarifies and defends three versions of the (...) many-subjects argument. One version poses the threat of conscious parts. Its key premise is that if physicalism is true, then not only you, but also certain parts of your body, are conscious. These parts might include your brain, your head, all-of-you-except-your-left-pinky, all-of-your-brain-except-one-neuron, or your left cerebral hemisphere. A second version poses the threat of conscious coinciders, things that currently occupy the same spatial region as you and share all your matter. Its key premise is that if physicalism is true, then not only you, but also some things that currently coincide with you, are conscious. These might include your body or the aggregate of particles of which you are currently composed. A third version poses the threat of conscious person candidates, the many human-body-shaped material objects in your vicinity that mostly overlap one another, differing only in a few peripheral atoms. This version claims that if physicalism is true, then there are many conscious person-candidates in your vicinity. -/- . (shrink)

This paper begins by applying a version of Timothy Williamson’s anti-luminosity argument to normative properties. This argument suggests that there must be at least some unknowable normative facts in normative Sorites sequences, or otherwise we get a contradiction given certain plausible assumptions concerning safety requirements on knowledge and our doxastic dispositions. This paper then focuses on the question of how the defenders of different forms of metaethical anti-realism (namely, error theorists, subjectivists, relativists, contextualists, expressivists, response dependence theorists, and constructivists) could (...) respond to the explanatory challenge created by the previous argument. It argues that, with two exceptions, the metaethical anti-realists need not challenge the argument itself, but rather they can find ways to explain how the unknowable normative facts can obtain. These explanations are based on the idea that our own attitudes on which the normative facts are grounded need not be transparent to us either. Reaching this conclusion also illuminates how metaethical anti-realists can make sense of instances of normative vagueness more generally. (shrink)