Quantification, Naturalness, Ontology

I’ve posted a draft of a paper ‘Quantification, Naturalness, Ontology’; this is slated for the volume New Waves on Metaphysics, edited by Allan Hazlett – but there’s a while until the deadline, so any comments on it would be really helpful. Here are some of the main themes, on which I’d be grateful to hear thoughts. (These are here condensed and presented without much argument; for further info, obviously, see the paper.)

Thesis 1: As in previous work, I’m concerned with defending a distinction between what there is and what there really is. Following Sider, in order to resist neo-Carnapianism we should insist that there’s a unique most natural existential quantifier: one that carves the world along its quantificational joints. But, there’s no need to say that the ordinary quantifiers of English are this natural quantifier. Naturalness is a reference magnet, to be sure, but it can be trumped by use. But we can introduce a quantifier (‘there really is . . .’) stipulated to be the most natural quantifier. As long as you’re happy with the naturalness talk in the first place, there’s now no mystery in saying that what there is might come apart from what there really is.

Thesis 2: I defend a two-dimensionalist approach to sentences like ‘there is a table’. Considering the universalist world as actual, this sentence requires a table as a truthmaker, and so considering other worlds as counterfactual, we should only judge the sentence to be true at those worlds if they contain certain complex objects, namely tables. But considering the nihilist world as actual, the charitable thing to say is not that that sentence is false but that it requires for its truth only the existence of simples arranged table-wise, and so considering other worlds as counterfactual, we should judge the sentence to be true at a world iff it contains simples arranged table-wise. An attractive consequence is this: assuming (which I hope is the case) that the nihilist world is actual, we have a nice explanation for what many people think is a necessary truth, the necessity of which otherwise looks mysterious, namely: if there are simples arranged table-wise then there is a table.

Thesis 3: It’s right to take Moorean truths about what there is as inviolable. What’s wrong, however, is to read the ontology straightforwardly off of them. The truth of ‘Here is a hand’ is indeed on a stronger footing than any conjunction of premises that entails its falsity. But that doesn’t mean that, e.g., compositional nihilism is false. Compositional nihilism, properly understood, is the claim that no complex objects really exist, and that is compatible with the claim that there are complex objects like hands. The proper methodology is to ask what are needed as the ontological grounds for the Moorean truths. There are no Moorean truths about what there really is.

Thesis 4: The problem of the many is easy. There’s a unique cat on the mat. But asking which collection of particles is the cat, is a bad question. There isn’t really a cat. You can only ask, which collection of particles grounds the fact that there is a cat? Answer: all of them (i.e. all the collections which the universalist thinks are candidates for being the cat). But that doesn’t mean that there are many cats, of course – the one sentence can have multiple grounds.

Thesis 5: Since the ontological commitments of a sentence are its ontological grounds, it’s an open possibility that there are true sentences that lack ontological grounds and hence carry no commitments. I suggest that the truths of mathematics are like this. It’s true that there is a prime number between 8 and 12; but it’s a mistake to think that this is ontologically committing to numbers. (And no ‘paraphrase’ of the sentence into something not quantifying over numbers is necessary to say this.) Mathematical claims are trivial in the sense that they make no demands, a fortiori no ontological demands, on the world. (Cf. what I say here to what Agustin Rayo says in his defence of mathematical trivialism in this excellent paper.)

Thesis 6: Actually not a thesis. I tentatively speculate that one could reduce necessity in the following way: p is necessary iff p lacks an ontological ground. Obviously, not everyone’s going to think this is extensionally adequate, since some think contingent negative existentials lack a ground, and others think everything has a ground, including necessary truths. But I think it looks quite hopeful, and would like to hear whether or not anyone else does.

In other news, Elizabeth and my paper (“Elizabeth and my” – is that right? It sounds terrible, but I can’t think what else it should be.) on the open future has been accepted by Phil Studies. But we’d still appreciate any comments on it, as it’s an issue we’re hopefully going to keep working on.