Wu Zhixin

Recently a number of works in meta-ontology have used a variant of J.H. Harris's collapse argument in the philosophy of logic as an argument against Eli Hirsch's quantifier variance. There have been several responses to the argument in the literature, but none of them have identified the central failing of the argument, viz., the argument has two readings: one on which it is sound but doesn't refute quantifier variance and another on which it is unsound. The central lesson I draw is that arguments against quantifier variance must pay strict attention to issues of translation and interpretation. The paper also has a substantial appendix in which I prove the equivalence of plural mereological nihilism and standard first-order atomistic mereology; results of this kind are often appealed to in the literature on quantifier variance but without many details on the nature or proof of the result.

Identity criteria are powerful tools for the metaphysician. They tell us when items are identical or distinct. Some varieties of identity criteria also try to explain in virtue of what items are identical or distinct. This Element has two objectives: to discuss formulations of identity criteria and to take a closer look at one notorious criterion of object identity, Leibniz's Law. The first section concerns the form of identity criteria. The second section concerns the better-regarded half of Leibniz's Law, the indiscernibility of identicals. The third section turns to the more controversial half of Leibniz's Law, the identity of indiscernibles. The author considers alternatives to Leibniz's Law as well as the possibility that there are no adequate identity criteria to be found.

I argue that dualism does not help assuage the perceived explanatory failure of physicalism. I begin with the claim that a minimally plausible dualism should only postulate a small stock of fundamental phenomenal properties and fundamental psychophysical laws: it should systematize the teeming mess of phenomenal properties and psychophysical correlations. I then argue that it is dialectically odd to think that empirical investigation could not possibly reveal a physicalist explanation of consciousness, and yet can reveal this small stock of fundamental phenomenal properties and psychophysical laws. I go on to consider a couple of different forms the dualist's laws could take, and argue that one version makes no progress on the hard problem of consciousness, and the other replaces the hard problem with a different problem that is just as hard.

Does the capacity to think require the capacity to sense? A lively debate on this topic runs throughout the history of philosophy and now animates discussions of artificial intelligence. Many have argued that AI systems such as large language models cannot think and understand if they lack sensory grounding. I argue that thought does not require sensory grounding: there can be pure thinkers who can think without any sensory capacities. As a result, the absence of sensory grounding does not entail that large language models cannot think or understand. I also consider to what extent quasi-sensory grounding can at least boost the performance of a language model.

A systematic overview of modern metaphysics, A Survey of Metaphysics covers all of the most important topics in the field. It adopts the fairly traditional conception of metaphysics as a subject that deals with the deepest questions that can be raised concerning the fundamental structure of reality as a whole. The book is divided into six main sections that address the following themes: identity and change, necessity and essence, causation, agency and events, space and time, and universals and particulars. It focuses on contemporary views and issues throughout, rather than on the history of metaphysics.

I argue that if David Lewis’ modal realism is true, modal realists from different possible worlds can fall in love with each other. I offer a method for uniquely picking out possible people who are in love with us and not with our counterparts. Impossible lovers and trans-world love letters are considered. Anticipating objections, I argue that we can stand in the right kinds of relations to merely possible people to be in love with them and that ending a trans-world relationship to start a relationship with an actual person isn't cruel to one's otherworldly lover.