Sketch of a Way of Thinking about Modality - Part 1

[This is old and my thinking on the subject has changed quite a bit (for the better I'm pretty sure). It may be of historical interest, or interesting if you're interested in how my ideas have developed. See my more recent 'Necessity as an Attribute of Propositions' - 22/10/15]

[UPDATE: This sketch, except for parts of part 2, will soon be made mostly redundant by a paper I am working on. I expect to make a draft of this paper available in early November. A link will appear here. - TH 13/10/2011]

[UPDATE 2: The paper mentioned above is here.]

[UPDATE 3, March 2013: What appears below has been left so far behind that I'm almost embarrassed about it. For my latest on these topics, see An Account of Subjunctive Necessity.]

This is the first installment of a two-part series of posts where I aim to sketch some ideas about modality which will feature in a book I am working on, Necessity and Conceptual Systems. The material is still very much under development, and I apologize for the obscurities which the reader will inevitably find in it. Comments and criticisms are very welcome.

In this first part, I will introduce the approach, and indicate how it handles the necessary a posteriori, using 'Hesperus is Phosphorus' as a case-study. In part 2 I will discuss the notion of de re modality, of essence, and natural-kind examples such as 'Water is H20', as well as some more general issues which arise on my approach (especially to do with epistemic modality and ascriptions of intentional content).

In the Golden Age of analytic philosophy, necessarily true propositions were widely taken to be those which are satisfied by (or 'come out true' on) all configurations of some conceptual or linguistic system. Possibility was understood in terms of satisfaction by at least one configuration. Our conceptual system, our means of understanding the world, is here thought of as something like a model, or a machine, which has moving parts, and which can be put into various positions or configurations. Each configuration can be thought of as corresponding to, or satisfying, or even being, a set of propositions. (I have taken many liberties in the formulation of this description.)

Conceptual or linguistic systems of the kind in question were thought to be describable with "semantical rules" for a language, and necessary propositions were thus commonly taken to be a priori and true "in virtue of the meaning" of the terms involved (cf. Carnap's Meaning and Necessity, Ayer's Language, Truth and Logic). This yields a notion of necessity reminiscent of the notion of truth-functional tautologousness. (Earlier, in the Tractatus - which was a major inspiration to both Ayer and Carnap - this relationship is much closer than mere reminiscence.)

This sort of view was attacked by Quine in at least two ways (cf. his 'Truth by Convention', 'Two Dogmas of Empiricism'). Quine's undifferentiated picture of language had a sobering or worrying effect, but it did not stop people carrying on with some version of the view in question. This is connected with the fact that it amounted to a kind of quietism or abstinence with respect to the relevant sorts of notions (semantic, modal), rather than a sustained attempt to attain positive insight about them.

The really decisive blow to the Golden Age view of modality came from Kripke. His fundamental contribution was to persuasively argue that the a priori does not coincide with the (metaphysically) necessary, and relatedly, that epistemic modality ("what could be the case") is to be distinguished from metaphysical modality ("what could have been the case" in a certain unrestricted sense). This contribution was closely bound up with Kripke's ideas concerning naming and reference, more on which in a moment. The recognition of the necessary a posteriori in particular, and the associated idea that conceivability doesn't entail possibility, has led to a reaction against views of modality of the Golden Age sort.

(About 'metaphysical modality': one sometimes hears it said of a philosopher that they countenance metaphysical modality, as though this indicates that the person holds some sort of doctrine, which may be quite esoteric. But 'metaphysical modality' is just a label for me - synonymous with 'subjunctive modality' - for a notion "detected" in the logic of language. That said, someone who felt this notion was, e.g., a trivial artifact of the way we happen to talk, rather than a deep artifact of the way we think, would probably not want to use this label.)

My approach to modality retains the view that necessity - metaphysical necessity - can be fruitfully understood in terms of invariance through all configurations of a conceptual system. But it also takes Kripke's separation of the a priori and the metaphysically necessary fully to heart. This latter point is one respect in which my approach differs from that of the two-dimensional semanticists. Another key contrast is that the possible worlds framework is not fundamental to my view.

Broadly speaking, I handle the necessary a posteriori by doing two things. Firstly, I work with a much more fine-grained notion of 'conceptual system' than did the logical empiricists. (The sense of 'fine-grained' here should become clearer in a moment.) Secondly, I embrace a certain kind of semantic externalism - roughly, the view that sense doesn't determine reference (other ways to put this which for me are roughly equivalent: intension doesn't determine extension, concept doesn't determine object).

I will illustrate how this works with respect to a classic example of the necessary a posteriori: 'Hesperus is Phosphorus'.¹

I follow Kripke in holding that proper names do not have reference-determining senses (which hangs together with semantic externalism via Putnam's idea of Twin Earth), and also that proper names do not have a semantics which can be given in the form of general conceptual content such as definite descriptions, or clusters thereof (irrespective of whether this content can be said to determine reference).

I do not, however, accept the (to my mind very strange and confused) idea that proper names are 'mere tags' (Ruth Barcan Marcus's phrase), that all there is to the meaning of a name is its referent, etc. This idea is sometimes associated with Mill's claim that names have no 'connotation', only 'denotation', and also with the phrase 'direct reference'.²

We have individual concepts - concepts of individuals, of particular objects - and we often associate these with proper names. This sheds light on Kripke's rigid designation thesis (the thesis that a referring proper name designates the same object in all possible worlds at which that object exists). If names are associated with individual concepts - concepts of particular objects - then it is immediate that they will designate the same object in all possible worlds where that object exists; designating another object is out of the question, since we are holding fixed the associated individual concept. We may thus distinguish rigid designators such as ordinary proper names, which designate rigidly because they are directly associated with individual concepts, from other rigid designators such as definite descriptions in mathematics.

Once we recognize individual concepts in this way, we can say that when someone accepts that Hesperus is Phosphorus (having previously taken them to be distinct), there is a change in their conceptual system - in the relevant fine-grained sense. Of course, in a more coarse-grained (and more ordinary) sense, we can say that they have before and after the same conceptual system. The fine-grained change consists in the unification of two individual concepts. The original concepts, we might say, are not blended irrevocably but remain as aspect-concepts united under a common master. From now on, it should be kept in mind that conceptual systems will usually be individuated here in this fine-grained sense.

In the former conceptual system (call this 'the Babylonian system'), where the Hesperus-concept is separated from the Phosphorus-concept, the distinctness of Hesperus and Phosphorus is invariant through all configurations of the system; if one positively believes that Hesperus and Phosphorus are distinct, one will say that, although it might conceivably turn out that Hesperus is Phosphorus after all, given that it isn't, Hesperus could not have been Phosphorus. (And one will of course be wrong.) In the latter conceptual system (call this 'our system'), where the Hesperus- and Phosphorus-concepts are unified, the identity of Hesperus and Phosphorus is invariant through all configurations of the system; when one knows that Hesperus is Phosphorus, one will say that, although it might conceivably turn out that Hesperus is distinct from Phosphorus after all, given that it isn't, Hesperus could not have been other than Phosphorus.

Now, with our fine-grained understanding of conceptual systems in place, I maintain that we can still say that all (metaphysically) necessarily true propositions are satisfied by all configurations of their host conceptual systems. We can even say that a truth is metaphysically necessary iff it is satisfied by all configurations of its host system. We just can't say that all propositions which are satisfied by all configuration of their host systems are necessary truths. So far, then, we can say what distinguishes necessary from contingent truths, but we can't say what distinguishes necessary truths from other proposition which are satisfied by all configurations of their host systems - we might call these 'false propositions of necessary character'. What can we say that will do this?

I think we can say something like: a proposition P is necessarily true iff it is satisfied by all configurations of its host system and the concepts involved in P are jointly adequate to their objects with respect to P.

First I want to say that I am not concerned to provide a reductive analysis of modal concepts. Relatedly, I am happy for the relevant modal notions and my ternary relation of 'adequacy' to be explanatory of each other; I do not suppose it is a one-way street, where my notion does all the explaining, nor do I take my notion to be more "fundamental" in any metaphysical sense. I am interested in showing (and making) connections.

I will make a start at explicating the above proposal by indicating how it applies to the 'Hesperus is Phosphorus' case. In the Babylonian system, the Hesperus-concept and the Phosphorus-concept are not unified (are taken to represent distinct objects), but they both have the same object, the same extension, and so together (jointly) they are inadequate to their objects with respect to 'Hesperus is not Phosphorus'. So their proposition 'Hesperus is not Phosphorus' fulfills the first condition given above, before the 'and' - it is satisfied by all configurations of their system - but it does not fulfill the second. Our Hesperus- and Phosphorus-concepts, which also have the same extension, are in contrast united, as aspect-concepts, under a common master concept (the concept of Venus). Hence they are adequate to their objects - or object - with respect to our proposition 'Hesperus is Phosphorus'.

Why do I not simply say that a proposition is necessarily true iff it is satisfied by all configurations of its host system and its concepts are jointly adequate to their objects? Why do I add 'with respect to that proposition'? I will explain this with an example. Assume for the sake of argument that Hesperus (Venus) is necessarily not intelligent - i.e. that Hesperus could not have been intelligent. Now, suppose someone believes that Hesperus is intelligent, and necessarily so - loosely speaking, that it is part of their concept of Hesperus that it is intelligent. In that case, their concept of Hesperus would not be adequate to its object with respect to 'Hesperus is intelligent'. But they may know, for all that, that Hesperus is Phosphorus, and so their concepts of Hesperus and Phosphorus might be jointly adequate to their object with respect to 'Hesperus is Phosphorus'.

Conversely, someone may know that Hesperus is necessarily not intelligent, while mistakenly believing that Hesperus is not Phosphorus, thus having an adequate conceptual situation with respect to propositions about the intelligence of Hesperus, but not with respect to propositions about the identity of Hesperus and Phosphorus.

Speaking broadly, necessity is, on this understanding, not simply a matter of a proposition having a certain status in a conceptual system. It is, as well as that, a matter of the system being adequate to its objects with respect to that proposition. The adequacy of some set of concepts to their objects obviously depends on the identity (and nature) of those objects - and this is not in general determined by the system. (This is how semantic externalism fits in.) Hence you cannot, in general, tell simply by looking at a proposition in a system whether or not it is necessarily true - there are a posteriori necessities.


The compatibility of externalism with rigid designation
(Postscript added 14 August, 2011.)

It may look as though there is a tension between my externalist claim that the extension of an individual concept is not in general determined by the concept itself, and the claim that names rigidly designate: if names are tied to individual concepts, and individual concepts do not in general determine their extension, it looks like a given individual concept can have different extensions in different environments. This is so (at least, when we individuate concepts internally) but there is no real tension here: the rigidity applies to names in use - names tied to token individual concepts embedded in an environment. Individual concepts are not like general concepts: the whole point of them is to apply to one particular object. And so the contrast between names and definite descriptions remains: when we consider counterfactual scenarios and hold the meaning of our terms fixed, our names which are tied to individual concepts always refer to 'the same object'.

This is all perfectly compatible with the fact that the same concept, in a different environment, might be connected up to a different object. The extension of our individual concepts may in some cases even change over time: if an object we know is replaced with a substitute, and we don't notice, after a while it will become true to say that our individual concept has changed its extension. But we don't let the extension change "across possible worlds" when representing counterfactual scenarios using a particular individual concept in a particular environment.

Part 2.

Individual concepts are under-discussed in contemporary philosophy. For further online reading on what they can do, see:

- My post at Philosophy, et cetera, 'An advertisement for individual concepts'

- A recent article by linguist Barbara Abbott, 'Support for Individual Concepts'.

- John McCarthy's article, 'First Order Theories of Individual Concepts and Propositions'. (Warning: arguably contains some use-mention confusion.)

Interestingly, neither of these authors are (primarily) philosophers.

1 I pass over one well-known issue here, to do with the fact that Hesperus/Phosphorus might not have existed. There is a discussion of this on Greg Frost-Arnold's blog. If one is really worried about this, consider instead the example 'If Hesperus exists, then Hesperus is Phosphorus'.

2 It should be noted, however, that Mill's claim is appropriate if 'connotation' is interpreted to mean 'reference-determining sense' or 'general conceptual content', and likewise that the phrase 'direct reference' is appropriate if 'direct' is interpreted to mean 'not via general conceptual content' or 'not via reference-determining sense'.

Three True Semantic Externalisms

Putnam's catchphrase 'Meanings ain't in the head', and the associated label 'semantic externalism', are not without ambiguity, as many authors have pointed out. My aim here is not to separate and discuss everything which 'semantic externalism' could reasonably mean, or even everything it has meant to philosophers, but rather to identify three different true and insightful things it can mean. I believe that having all three insights, and having them separate, can pay big dividends in the philosophies of language and modality, but I won't try to make a case for that here.

We can look at language and thought on three levels:

1. Local marks and noises, local neural and sensory events.
2. Sense; game and moves; conceptual system and configuration; intension; internal content.
3. Reference; extension; external content in abstraction from internal.

We can individuate thoughts and propositions according to 2 alone, 3 alone, or 2 and 3 together. For example, on 2 alone, 'I am here' is the same proposition when you an I utter it, or when I utter it in different locations - we are making the same sort of move in the same sort of language-game. On 3 alone, 'I am here' expresses the same proposition as 'John is at location X' when the former is uttered by John at location X - extension (reference) is the same. On 2 and 3 together, 'I am here' is distinct when uttered by different people and at different locations, due to difference in extension, and also distinct from 'John is at location X' when both are uttered by John at X, due to conceptual difference (difference in sense, intension, language-game).

To take another kind of example, on 2 alone, 'Hesperus is Phosphorus' is distinct from 'Hesperus is Phosphorus', but identical to the Twin Earthian thought or proposition 'Hesperus is Phosphorus' - call this thought or proposition 'Twin-"Hesperus is Phosphorus"'. On 3 alone, 'Hesperus is Phosphorus' expresses the same proposition as 'Hesperus is Hesperus', but not the same proposition as any thought about Twin Venus. On 2 and 3 together, 'Hesperus is Phosphorus' is distinct from 'Hesperus is Hesperus' (due to difference with respect to 2), as well as from Twin-'Hesperus is Phosphorus' (due to difference with respect to 3) and from Twin-'Hesperus is Hesperus' (due to difference with respect to both 2 and 3).

The three semantic externalisms which I want to identify and separate can all be seen as underdetermination theses. They are:

Wittgenstein externalism: 1 doesn't determine 2 (i.e. local happenings don't determine intension).
Intension-based Putnam externalism: 2 doesn't determine 3 (i.e. intension doesn't determine extension).
Happenings-based Putnam externalism: 1 doesn't determine 3 (i.e. local happenings don't determine extension).

Note that the first two externalisms don't imply the third - while the relation of determining is arguably transitive, the relation of not determining isn't. Note also that 'determine' here means 'always determine' or 'generally determine' - determination in some cases is not being ruled out. I should also say that I attach no great importance to the labels used here for the three externalisms.




Finally, note that the expression 'internal content' above is not supposed to express the problematic notion of narrow content. Narrow content is often thought of as a kind of minimal intension, sense or internal content which is determined by happenings inside an agent's brain or body. That problematic notion isn't being discussed here.

I am currently working on a book on modality, in which this separation plays a key role.

Tristan Haze

Suggested reading

For Wittgenstein externalism: Wittgenstein's Philosophical Investigations. Also his Zettel, and other later work.

For the Putnam externalisms: Putnam's classic 1975 paper 'The meaning of 'meaning', published in Minnesota Studies in the Philosophy of Science 7:131-193, reprinted in The Twin Earth Chronicles: Twenty Years of Reflection on Hilary Putnam's ``the Meaning of `Meaning' '' edited by Andrew Pessin & Sanford Goldberg, 1996, published by M. E. Sharpe.

Breckenridge and Magidor on Arbitrary Reference: An apparent counterexample

[This is an early draft of a paper which, since being posted, has grown and changed title. Email me if you would like a copy. - TH 9/4/15]

In an interesting paper forthcoming in Phil. Studies, Breckenridge and Magidor argue for this thesis:

Arbitrary Reference (AR): It is possible to fix the reference of an expression arbitrarily. When we do so, the expression receives its ordinary kind of semantic-value, though we do not and cannot know which value in particular it receives.

Their primary argument in favour of AR is that it can be used to give an attractive account of 'instantial reasoning' such as this (their 'Argument 1'):

(1) There is someone x such that for every person y, x loves y [Premise]
(2) Let John be such a person
(3) For every person y, John loves y [Existential Instantiation on 1]
(4) Let Jane be an arbitrary person
(5) John loves Jane [Universal Instantiation on 3]
(6) There is some person x such that x loves Jane [Existential Generalisation on 5]
(7) But since Jane was an arbitrary person, for every person y there is some person x such that x loves y [Universal Generalisation on 6] 

I will not attempt to rehearse, or even summarize, their arguments, since they state them well and their paper is freely available on Magidor's website. My purpose here is to give an apparent counterexample to the claim that AR can be used to give an attractive account of instantial reasoning.

The following appears to be a logical truth: 

(Unref) If (all unreferred-to objects are white and there is an unreferred-to object), then there is a white object.

(By 'unreferred-to object', I mean an object which is never referred to by anyone or anything.) Here is a quasi-formal argument for (Unref):

(1) All unreferred-to objects are white and there is some unreferred-to object. [Assumption]
(2) All unreferred-to objects are white. [Conjunction Elimination on 1]
(3) There is some unreferred-to object. [Conjunction Elimination on 1]
(4) Let O be such an object.
(5) O is white. [Universal Instantiation on 2]
(6) There is some white object [Existential Generalization on 5]

(Unref) now follows from (1) - (6) by conditional proof.

This seems to be a valid argument. But the theory of instantial reasoning advanced by Breckenridge and Magidor seems to imply that the expression 'O' above refers to an unreferred-to object, which is absurd.

Tristan Haze
The University of Sydney

Reference
Breckenridge, Wylie & Magidor, Ofra (forthcoming). 'Arbitrary reference'. Philosophical Studies. 

There is a post about this paper on Ross Cameron's blog here.

On the Interpretation of the Propositional Calculus

I've just posted another (more recent) longer article on my homepage, On the Interpretation of the Propositional Calculus. The next post will be a short article, I promise.

Comments are welcome.  Here is the abstract:

The question considered is 'How can formulae of the propositional calculus be brought into a representational relation with the world?'. Four approaches are discussed: (1) the denotational approach, on which formulae are taken to denote objects, (2) the abbreviational approach, on which formulae and connectives are taken to abbreviate natural-language expressions, (3) the truth-conditional approach, on which truth-conditions are stipulated for formulae, and (4) the modelling approach, on which formulae, together with either valuation- or proof-theory, are regarded as an abstract structure capable of bearing (via stipulation) a representational relation to the world.

The modelling approach is developed here for the first time. The simple technical apparatus used for this is then applied to two issues in the philosophy of logic. (1) I demonstrate a corollary or converse to Carnap's result that certain 'non-normal' valuation-functions can be added to the set of admissible valuations of formulae without destroying the soundness and completeness of standard proof-theories. This sheds considerable light on a recent thread of the inferentialism debate which involves dialectical use of Carnap's result. (2) I show how the approach can be extended to quantification theory, by defining a model-theoretic notion of validity equivalent to the usual one, but making use of a proof-theoretic apparatus in place of the device of assigning values to formulae. This sheds light on the close relationship between proof- and valuation-theory.

On Identity Statements

I've just posted a longer article on my homepage, On Identity Statements: Against the ascriptional views.

Apart from minor revisions, it is about 18 months old now. I would not write it in the same way now, but I still hold the views expressed there. Comments welcome, here or by email (my email address is on my homepage and on the 'About/contribute' page here).

UPDATE 21/06/2016: I have removed the link, as a descendant of this paper called 'On Identity Statements: In Defense of a Sui Generis View' has finally been accepted for publication.

Comment on Brogaard and Salerno's 'Counterfactuals and Context'

This is a draft of a paper.

It is quite commonly believed by contemporary logicians that contraposition, strengthening the antecedent and hypothetical syllogism fail for counterfactuals. In their (2008), Brogaard and Salerno argue that the putative counterexamples to these principles are actually no threat, on the grounds that they involve a certain kind of illicit contextual shift.

Here I suggest that this particular kind of contextual shift, if it is properly so called, is not generally illicit, and therefore the counterexamples cannot be blocked with the kind of blanket restriction Brogaard and Salerno appear to advocate. This sort of restriction, I suggest, ought to be made at the level of particular inference rules.

Brogaard and Salerno conduct their discussion within the framework of the standard Lewisian account of counterfactuals, which says that

a subjunctive of the form ‘if A had been the case, B would have been

the case’ is true at a world w iff B is true at all the A-worlds closest (or

most relevantly similar) to w.¹

They introduce the term 'background facts', by which they mean to designate 'the respects in which A-worlds are relevantly similar to w'. Thus every counterfactual, once understood on the standard theory, is attached to a set of background facts. Now, the central claim of their article is that 'the set of contextually determined background facts must remain fixed when evaluating an argument involving subjunctives for validity'. One set of background facts per argument. Let us call this the Brogaard-Salerno Stricture. Brogaard and Salerno say that to break this stricture is to commit an illicit contextual shift, and since the putative counterexamples to contraposition etc. break the stricture, they should not be accepted.

For an argument to comply with Brogaard-Salerno Stricture, all counterfactuals occurring within it have to be alike in background facts. What I wish to point out is that this condition is plainly unsatisfied by a great many arguments, including the following:

If Mary hadn't had breakfast, she would have lunched sooner.

If John had worn black shoes, he would have worn black socks.

Therefore, if Mary hadn't had breakfast, she would have lunched sooner, and if John had worn black shoes, he would have worn black socks.

For the first premise, one of the background facts might be that Mary has a normal appetite. Another might be that she does not like to go hungry. These are plainly irrelevant to the second premise, i.e. these are plainly not background facts for the second premise. Conversely, John's sense of style has nothing to do with the first. We cannot stipulate that these premises are attached to the same set of background facts without doing obvious violence to their meaning. These two premises, if they are to be understood the way they are meant to be understood, cannot figure in the same argument without breaking the Brogaard-Salerno Stricture. But the above argument is obviously valid. Therefore the stricture is not generally appropriate. I suggest that a better course would be to restrict particular rules - starting with contraposition, strengthening the antecedent and hypothetical syllogism - in respect of background facts pertaining to counterfactual evaluation, rather than deductive argumentation in general. Other rules may be fair game too. In this connection, consider this passage:

But suppose we are wrong about this. Suppose shifting context mid-inference is no fallacy at all. Then a rather surprising consequence follows. Modus ponens - which many possible world accountants love and cherish - fails too. (2008, p. 44).

On my suggestion, the evidence for the claim of the last sentence might motivate the view that modus ponens needs to be restricted too - but still, not all deductive argumentation. Conjunction introduction, for example, is prima facie OK without such a strong restriction.

Tristan Haze

The University of Sydney

References

Brogaard, B. and Salerno, J. 2008. Counterfactuals and context. Analysis 68.1: 39–46.

Lewis, D. 1973. Counterfactuals. Oxford: Blackwell.   

1 This is the formulation used by Brogaard and Salerno. It is adapted from Lewis (1973). 

A Note on Hofweber's Distinction between Internal and External Quantification

ABSTRACT: Thomas Hofweber's distinction between internal and external quantification is crucial to the solution he offers to his now well-known puzzle about ontology. Here I argue that this distinction is not well motivated by the considerations he employs.

In a series of interesting papers (2000, 2005b, 2007), Thomas Hofweber has identified a puzzle about ontology and developed a novel solution. Briefly, the puzzle is that questions such as 'Do numbers exist?' seem trivial from one point of view, but highly contentious from another. On the one hand, it is obvious that, e.g., there are even numbers smaller than 6. It follows trivially from this obvious statement that there are numbers. On the other hand, it is hotly disputed among philosophers whether or not there are numbers. Hofweber himself denies their existence. Nonetheless, he agrees that, e.g., there are even numbers smaller than 6.

Hofweber's solution to this puzzle crucially involves a distinction between two kinds of quantification which he calls 'internal' and 'external'. External quantification is familiar; externally quantified statements impose conditions on a domain of objects. Hofweber plausibly argues (2000, 2005b) that we must also recognize a kind of quantification which does not impose such conditions. His strategy is to highlight a certain 'inferential role' which quantifiers play in natural language, which enables them to function as place-holders for incomplete information; suppose we knew that Fred admires Thomas Edison, but then forgot this, remembering only that there is someone Fred admires. Hofweber argues that 'this situation is completely general', and that 'the only instances of the quantifier might be things that don't exist'.¹

With this distinction between internal and external quantification on board, Hofweber's solution to the puzzle about ontology is that the "trivial arguments" to the existence of contentious entities are indeed trivially valid, on the proviso that the quantifiers in their conclusions are given an internal reading. Questions about what there is, where 'what there is' is construed externally, thus remain as a non-trivial subject matter for ontology.

My object here is to show that the distinction Hofweber intends to make is not what it may appear to be at first glance, and furthermore that it cannot in fact be motivated solely by means of the considerations (indicated above) which he employs.

Let us begin with the question: why can't external quantification play the role of facilitating the expression of incomplete information? From the considerations offered, it seems that the only reason is that, as Hofweber says, the only instances of the quantifier might be things that don't exist. Thus we might think of internal quantifiers as characterised by the fact of ranging over both merely intentional objects and not-merely-intentional objects, in contrast to external quantifiers, which range over not-merely-intentional objects only. (I will call this 'the simple intentional-permissive understanding' of internal quantification.) This, however, is not how Hofweber conceives the distinction.

This becomes clear once we look at his views about arithmetical discourse with the distinction between the merely intentional and the not-merely-intentional in mind.² You can look for a prime between 24 and 28, and thus be looking for something. However, you will not find one: in this sense, there is no such thing. Hofweber fully recognizes this distinction, while nonetheless believing all quantification in arithmetic to be internal. Thus Hofweber's distinction between internal and external quantification cannot be understood in terms of the pre-existing distinction between the intentional and the not-merely-intentional. And yet this pre-existing distinction seems a natural and sufficient basis for a notion of quantification fit to play the inferential role Hofweber identifies. Therefore his consideration of this role is not by itself a good motivation for his internal-external distinction.

Note carefully that this argument does not require that the simple intentional-permissive understanding of internal quantification be a suitable basis for a solution to the puzzle about ontology. Furthermore, it does not rule out Hofweber's using the puzzle itself as a motivation for a special reading of quantification. The point is that he has not succeeded in establishing an independent motivation for such a reading.

It might be objected that I have not made an adequate case for the possibility of the simple intentional-permissive understanding of internal quantification. But I am not seeking to establish this conclusively; only, given that Hofweber has identified an inferential role which calls for a non-external reading of the quantifiers, the simple intentional-permissive conception is prima facie a better candidate than one based on Hofweber's internal-external distinction (considered apart from any puzzle about ontology). It may seem as though I'm not being quite fair, since I haven't really made his distinction clear in its own right. But I have no idea how to do this. Hofweber wants a reading of quantification such that the following comes out true:

There is an x such that x is not a merely intentional object, and x does not exist (in the external sense).

It has not been made sufficiently clear that such a reading is available.

Finally, one might wonder how Hofweber's internalism about arithmetical discourse avoids trivializing arithmetic. For on this conception, so-called "existence statements" about merely intentional objects (e.g. the largest prime) can easily come out true. Hofweber handles this with a supplementary doctrine to the effect that quantification in arithmetic is generally restricted to statements which have instances containing number words or numerals ('one', '46', etc.). However, and as Hofweber himself acknowledges, this sort of account cannot be extended to the reals, since we do not have number words for all of them.³ This gives rise to the worry that whatever the truth is about our quantification over the reals, it may also account for our quantification over natural numbers in arithmetic, rendering internalism about arithmetic theoretically superfluous.

Tristan Haze

The University of Sydney

References

Hofweber, T. 2000. 'Quantification and Non-Existent Objects', in Empty Names, Fiction and the Puzzles of Non-Existence, eds. Everett, A. and Hofweber, T. CSLI Publications.

Hofweber, T. 2005a. 'Number Determiners, Numbers, and Arithmetic', The Philosophical Review 114:2.

Hofweber, T. 2005b. 'A Puzzle about Ontology', Nôus 39:2.

Hofweber, T. 2007. 'Innocent Statements and their Metaphysically Loaded Counterparts', Philosophers' Imprint 7:1, <www.philosophersimprint.org/007001/>.

These papers are available on Hofweber's homepage: http://web.mac.com/hofweber/Thomas_Hofwebers_homepage/Papers.html

1 (2000), p 16.

2 These views are indicated in his (2005a).

3 Thanks to Thomas Hofweber for helpful correspondence on this and related points.