Jonathan Simon

This paper is a fresh attempt to articulate the role of a theory of truthmakers. We argue that truthmaker theory constitutes a cornerstone of good methodology in metaphysics, but that a conflation of truthmaker theory with the theory of truth has been responsible for certain excesses associated with truthmaker-based approaches in the recent literature. If truthmaker theory is not a component of a theory of truth, then truthmaker maximalism – the view that every truth has a truthmaker – loses its primary motivation. More generally, if the task of truthmaker theory is not to provide a definition or account of truth in truthmaker terms, there is no pressing need for hard, a priori principles stating which truths have truthmakers and which do not.

Theodore Sider has recently produced an argument which he takes to show that three-dimensionalism is incompatible with the possibility of time travel. I wish to argue that there is indeed a problem for the three-dimensionalist who wishes to countenance time travel, but that Sider has misdiagnosed it. I show why his putative challenge fails, and furthermore that if it were to succeed this would be as problematic for a wide class of four-dimensionalist positions, including Sider’s own, as it would be for three-dimensionalism. Finally, I present the problem that the possibility of time travel genuinely poses for the three-dimensionalist.

I argue that there can be no such thing as a borderline case of the predicate ‘phenomenally conscious’: for any given creature at any given time, it cannot be vague whether that creature is phenomenally conscious at that time. I first defend the Positive Characterization Thesis, which says that for any borderline case of any predicate there is a positive characterization of that case that can show any sufficiently competent speaker what makes it a borderline case. I then appeal to the familiar claim that zombies are conceivable, and I argue that this claim entails that there can be no positive characterizations of borderline cases of ‘phenomenally conscious’. By the Positive Characterization Thesis, it follows that ‘phenomenally conscious’ can not have any borderline cases.