ABSTRACTIn the target article ‘If-Thenism’, Stephen Yablo develops a novel form of if-thenism, that appeals to the notion of logical subtraction. In this commentary, I explore the limits of Yablo's proposed subtraction procedure, by leaning on an analogy with photographic subtraction. In particular, I will argue that there will be cases when there's nothing interesting left after the subtraction and, as a consequence, there are serious limits to the applicability of the subtraction procedure.

Mark Colyvan (2010) raises two problems for ‘easy road’ nominalism about mathematical objects. The first is that a theory’s mathematical commitments may run too deep to permit the extraction of nominalistic content. Taking the math out is, or could be, like taking the hobbits out of Lord of the Rings. I agree with the ‘could be’, but not (or not yet) the ‘is’. A notion of logical subtraction is developed that supports the possibility, questioned by Colyvan, of bracketing a theory’s (...) mathematical aspects to obtain, as remainder, what it says ‘mathematics aside’. The other problem concerns explanation. Several grades of mathematical involvement in physical explanation are distinguished, by analogy with Quine’s three grades of modal involvement. The first two grades plausibly obtain, but they do not require mathematical objects. The third grade is likelier to require mathematical objects. But it is not clear from Colyvan’s example that the third grade really obtains. (shrink)

This paper concerns Yablo’s theory of asserted content as it is developed in his new book Aboutness. Yablo’s central idea is that in order to specify the asserted content of a sentence, we have to subtract those parts of its full semantic content that concern irrelevant subject matters. The paper argues that it is doubtful whether Yablo’s account successfully deals with its most basic envisaged application: to account for a difference of apparent truth value in cases of (...) ordinary presupposition failure. In addition, some doubts are raised concerning the success of the extension of Yablo’s account to fictional talk, the informativeness of identity statements, and ontological commitments of number talk. (shrink)

ABSTRACTThe paper explores Stephen Yablo's suggestion that ‘If-Thenism’ in the philosophy of mathematics is best formulated as the thesis that the real content of a mathematical claim C is the result of subtracting the potentially problematic metaphysical commitments of mathematics from C [Yablo 2017]. Yablo's proposal assumes that some propositions make others true. The present discussion assumes that propositions are coarse-grained sets of possible worlds and asks what Yablo's proposal looks like on that assumption. The (...) conclusion is that the adequacy of the proposal turns on hard-to-settle questions about the truthmakers for propositions expressed by material conditionals. (shrink)

ABSTRACTIn the target article, Stephen Yablo appeals crucially to the notion of surplus content. But when he does so, it is by appeal to the notion of mathematical addition and subtraction. In this commentary, I argue that the analogy with mathematical subtraction is underdeveloped and potentially misleading.

Aboutness has been studied from any number of angles. Brentano made it the defining feature of the mental. Phenomenologists try to pin down the aboutness-features of particular mental states. Materialists sometimes claim to have grounded aboutness in natural regularities. Attempts have even been made, in library science and information theory, to operationalize the notion. But it has played no real role in philosophical semantics. This is surprising; sentences have aboutness-properties if anything does. Aboutness is the first book to examine through (...) a philosophical lens the role of subject matter in meaning. A long-standing tradition sees meaning as truth-conditions, to be specified by listing the scenarios in which a sentence is true. Nothing is said about the principle of selection--about what in a scenario gets it onto the list. Subject matter is the missing link here. A sentence is true because of how matters stand where its subject matter is concerned. Stephen Yablo maintains that this is not just a feature of subject matter, but its essence. One indicates what a sentence is about by mapping out logical space according to its changing ways of being true or false. The notion of content that results--directed content--is brought to bear on a range of philosophical topics, including ontology, verisimilitude, knowledge, loose talk, assertive content, and philosophical methodology. Written by one of today's leading philosophers, Aboutness represents a major advance in semantics and the philosophy of language. (shrink)

[Stephen Yablo] The usual charge against Carnap's internal/external distinction is one of 'guilt by association with analytic/synthetic'. But it can be freed of this association, to become the distinction between statements made within make-believe games and those made outside them-or, rather, a special case of it with some claim to be called the metaphorical/literal distinction. Not even Quine considers figurative speech committal, so this turns the tables somewhat. To determine our ontological commitments, we have to ferret out all (...) traces of nonliterality in our assertions; if there is no sensible project of doing that, there is no sensible project of Quinean ontology. /// [Andre Gallois] I discuss Steve Yablo's defence of Carnap's distinction between internal and external questions. In the first section I set out what I take that distinction, as Carnap draws it, to be, and spell out a central motivation Carnap has for invoking it. In the second section I endorse, and augment, Yablo's response to Quine's arguments against Carnap. In the third section I say why Carnap's application of the distinction between internal and external questions runs into trouble. In the fourth section I spell out what I take to be Yablo's version of Carnap. In the last I say why that version is especially vulnerable to the objection raised in the second. (shrink)

In his latest book Aboutness, Stephen Yablo has proposed a new ‘easy road’ nominalist strategy: instead of engaging in the hard work of paraphrasing a scientific theory which presupposes numbers in a nominalistically acceptable way, nominalists are, according to Yablo, entitled to accept the theory as true, while rejecting the existence of numbers, if from the theory’s content the presupposition that there are numbers can be subtracted away, yielding thus a number-free content remainder. Perfect extricability, i.e. extricability (...) in every possible world, of the presupposition that there are numbers from any content apparently involving them is, in Yablo’s view, sufficient to make the existence of numbers moot. In this paper I will argue that perfect extricability fails as a criterion of ontological mootness. (shrink)

How does your information change when you learn that something might be the case, where the modal “might” is epistemic? On the orthodox view, a proposition is added to your information base; on the view defended here, no propositions are added to your information base but some are removed from it. I argue that Stephen Yablo’s recent attempt to define this removal operation as a kind of propositional subtraction fails, offer a definition of my own in terms of (...) the part–whole relations between the truthmakers of the propositions one accepts, and argue that a deontic analogue of this account solves a problem about permission posed long ago by David Lewis. (shrink)

Kripke, argued like this: it seems possible that E; the appearance can't be explained away as really pertaining to a "presentation" of E; so, pending a different explanation, it is possible that E. Textbook Kripkeans see in the contrast between E and its presentation intimations of a quite general distinction between two sorts of meaning. E's secondary or a posteriori meaning is the set of all worlds w which E, as employed here, truly describes. Its primary or a priori meaning (...) is the set of all w such that if w is actual, then E is true. "Conceivability error" occurs when a primary possibility is mistaken for a secondary one. Textbook Kripkeanism is rejected on the grounds that it makes meaning too modal and modality too much a matter of meaning. (shrink)

Many topics have not been covered, in most cases because I don't know quite what to say about them. Would it be possible to add a decidability predicate to the language? What about stronger connectives, like exclusion negation or Lukasiewicz implication? Would an expanded language do better at expressing its own semantics? Would it contain new and more terrible paradoxes? Can the account be supplemented with a workable notion of inherent truth (see note 36)? In what sense does stage semantics (...) lie “between” fixed point and stability semantics? In what sense, exactly, are our semantical rules inconsistent? In what sense, if any, does their inconsistency resolve the problem of the paradoxes?The ideals of strength, grounding, and closure together define an intuitively appealing conception of truth. Nothing would be gained by insisting that it was the intuitive conception of truth, and in fact recent developments make me wonder whether such a thing exists. However that may be, until the alternatives are better understood it would be foolish to attempt to decide between them. Truth gives up her secrets slowly and grudgingly, and loves to confound our presumptions. (shrink)

ontology metaontology wright platonism fregean existence epistemology.

Essence and causation are fundamental in metaphysics, but little is said about their relations. Some essential properties are of course causal, as it is essential to footprints to have been caused by feet. But I am interested less in causation's role in essence than the reverse: the bearing a thing's essence has on its causal powers. That essencemight make a causal contribution is hinted already by the counterfactual element in causation; and the hint is confirmed by the explanation essence offers (...) of something otherwise mysterious, namely, how events exactly alike in every ordinary respect, like the bolt'ssuddenly snapping and its snapping per se, manage to disagree in what they cause. Some prior difference must exist between these events to make their causal powers unlike. Paradoxically, though, it can only be in point of a property, suddenness, which both events possess in common. Only by postulating a difference in themanner — essential or accidental — of the property's possession is the paradox resolved. Next we need an account of causation in which essence plays an explicit determinative role. That account, based on the idea that causes should becommensurate with their effects, is thatx causesy only if nothing essentially poorer would have done, and nothing essentially richer was needed. (shrink)

….it [is] wholly irrational to regard as doubtful matters that are perceived clearly and distinctly by the understanding in its purity, on account of mere prejudices of the senses and hypotheses in which there is an element of the unknown.Descartes, Geometrical Exposition of the MeditationsSubstance dualism, once a main preoccupation of Western metaphysics, has fallen strangely out of view; today’s mental/physical dualisms are dualisms of fact, property, or event. So if someone claims to find a difference between minds and bodies (...) per se, it is not initially clear what he is maintaining. Maybe this is because one no longer recognizes ‘minds’ as entities in their own right, or ‘substances.’ However, selves - the things we refer to by use of ‘I’ - are surely substances, and it does little violence to the intention behind mind/body dualism to interpret it as a dualism of bodies and selves. If the substance dualist’s meaning remains obscure, that is because it can mean several different things to say that selves are not bodies. (shrink)

A reply to Fine’s critique of Aboutness. Fine contrasts two notions of truthmaker, and more generally two notions of “state.” One is algebraic; states are sui generis entities grasped primarily through the conditions they satisfy. The other uses set theory; states are sets of worlds, or, perhaps, collections of such sets. I try to defend the second notion and question some seeming advantages of the first.

Knowledge is closed under implication, according to standard theories. Orthodoxy can allow, though, that apparent counterexamples to closure exist, much as Kripkeans recognize the existence of illusions of possibility which they seek to explain away. Should not everyone, orthodox or not, want to make sense of “intimations of openness”? This paper compares two styles of explanation: evidence that boosts P’s probability need not boost that of its consequence Q; evidence bearing on P’s subject matter may not bear on the subject (...) matter of Q. (shrink)

The real distinction between mind and body -- Is conceivability a guide to possibility? -- Textbook kripkeanism and the open texture of concepts -- Coulda, woulda, shoulda -- No fool's cold : notes on illusions of possibility -- Beyond rigidification : the importance of being really actual -- How in the world? -- Mental causation -- Singling out properties -- Wide causation -- Causal relevance : mental, moral, and epistemic.

Part/whole is said in many ways: the leg is part of the table, the subset is part of the set, rectangularity is part of squareness, and so on. Do the various flavors of part/whole have anything in common? They may be partial orders, but so are lots of non-mereological relations. I propose an “upward difference transmission” principle: x is part of y if and only if x cannot change in specified respects while y stays the same in those respects.

….it [is] wholly irrational to regard as doubtful matters that are perceived clearly and distinctly by the understanding in its purity, on account of mere prejudices of the senses and hypotheses in which there is an element of the unknown.Descartes, Geometrical Exposition of the MeditationsSubstance dualism, once a main preoccupation of Western metaphysics, has fallen strangely out of view; today’s mental/physical dualisms are dualisms of fact, property, or event. So if someone claims to find a difference between minds and bodies (...) per se, it is not initially clear what he is maintaining. Maybe this is because one no longer recognizes ‘minds’ as entities in their own right, or ‘substances.’ However, selves - the things we refer to by use of ‘I’ - are surely substances, and it does little violence to the intention behind mind/body dualism to interpret it as a dualism of bodies and selves. If the substance dualist’s meaning remains obscure, that is because it can mean several different things to say that selves are not bodies. (shrink)

ABSTRACTAn undemanding claim ϕ sometimes implies, or seems to, a more demanding one ψ. Some have posited, to explain this, a confusion between ϕ and ϕ*, an analogue of ϕ that does not imply ψ. If-thenists take ϕ* to be If ψ then ϕ. Incrementalism is the form of if-thenism that construes If ψ then ϕ as the surplus content of ϕ over ψ. The paper argues that it is the only form of if-thenism that stands a chance of being (...) correct. (shrink)