Saturday 24 December 2016

What Are My Problems Now?

This is a follow-up to What Was My Problem?.

1. The Basis of Puzzlement about Modality

One line of investigation I would like to pursue now is into what might be called the basis of the puzzlement about modality. And as suggested by my experience of vaguely wrestling with a bunch of problems, before realizing that my strongest leading ideas for my thesis were really about some of these problems rather than others, I think this line of investigation may itself call for the distinguishing of various problems.

One locus of puzzlement about modality is the notion of metaphysical or subjunctive necessity as it applies to propositions. And one question about this notion is whether, and how, meaning comes into the picture. Also, just the question of how this notion relates to other notions, and the extent to which it can be analyzed (not necessarily in non-modal terms). Those problems are addressed, properly I hope, by the account in my thesis. But lots of what I was wrestling with at the beginning of my research remains, and does not attach specifically to the notion of subjunctive necessity de dicto; there is a lot that is puzzling about modality that my thesis does not address.

One puzzling thing which borders directly on my thesis work, and does have to do with the notion of subjunctive necessity de dicto, is the question of how this relates to de re modal constructions and quantification into modal contexts. But I have been very frustrated in my research here, and to be honest I have come to feel like it is a bit of a minor, abstruse issue compared to some of the more fundamental problems about modality (although I have no doubt that very interesting work could be done on that issue, and have a couple of ideas).

A more fundamental area I would like to work on is indicated by the question: Why is modality puzzling at all? But here too there are probably several puzzling things to distinguish. One thing I am not primarily thinking of, although it may end up becoming relevant to the problems I am grasping at, are questions about modality in an extremely general sense. For instance, the question of what unifies all uses of expressions which we call modal, or which we say are about possibility or whatever - including 'You can come in if you like', 'It could be that John is on his way', 'It is impossible for two colours to be in the same place', '"Hesperus is Phosphorus" is necessarily true', 'I can lift this weight', 'This apparatus has four possible configurations'. Also, questions about what generalizations can be made covering all or at least a great diversity of such uses, for instance about logical implication relations between them.

Rather, I am interested in trying to get at the basis of our puzzlement about what may be called objective modality. What does 'objective modality' mean? Well, one clear thing it does is exclude epistemic modals, like 'It could be that John is on his way' in natural uses. These are to be put to one side - at least initially - in the line of investigation I want to pursue. Likewise with uses of modal language having to do with permission. Within the puzzlement attaching primarily to objective modality as opposed to these set-aside kinds, important distinctions may have to be made. For instance, there may be a need to distinguish between more down-to-earth uses of modal language, for instance 'I can lift this weight', from what may be called more metaphysical uses - but not 'metaphysical' in the sense often used in modal philosophy, to mean either something like 'objective' or something a bit more specific, like picking out what I pick out with 'subjunctive'. Rather, by 'more metaphysical uses' I mean uses which are so to speak puzzling from the start. That is, where there isn't as much non-problematic, clearly useful use as in the case of 'I can lift this weight' and the like. E.g. 'The world could have been otherwise', 'Aristotle is essentially human'.

One way forward in this line of investigation would be to look critically and closely at philosophers' attempts to give a sense of the puzzlement about (objective) modality, often as a preliminary to some account or a survey of accounts. For instance, Sider's remarks on the subject in 'Reductive Theories of Modality'. But I think it will also be important to look within, so to speak, and keep seriously asking myself 'What is it that puzzles me about this?'.

2. Propositions and Meaning, Language Systems, and Our Expectations

Another line of investigation I would like to pursue has to do with the account of propositions and meaning sketched in chapter 6 of my thesis. That account appeals to a notion of an expression's internal meaning, cashed out in terms of the expression's role in the language system to which it belongs. This may raise questions about the nature of the system, and how we should think of it and describe it. In my thesis, I tried to remain quite open about this, emphasizing that I was offering a sketch, and that different fillings in of the detail here may be possible.

It was hard to avoid striking a false note here. For I do not think this is the whole story about my sketch, and the middle-Wittgenstein idea about role-in-system which it takes over; it may not be quite right to just think about it as a sketch of a theory, where some aspects are not filled in. For the very idea of what needs filling in, and how, should I think be scrutinized. It is not that I am advocating quietism, or defeatism, about questions about the 'language system' I appeal to. But I think that some of our expectations here may be in need of examination.

A curious thing happens in this territory - it is easy to become disoriented, and wonder what the problem was and what is needed now. Maybe sometimes in philosophy, as we solve problems, they slip from our grasp. Sometimes there is a strange feeling where we wonder something like: how could there be a solution here which is given in mere words? How could that ever do? We feel we still need to be taught something, or shown something. Could it be something practical, so to speak? I.e. something we could get through practice?

In the new year, I intend to use this blog to try to make some inroads into these and related problems.

Wednesday 21 December 2016

On Why Crude Analyses are Often the Most Enlightening

The crudest conceptual analyses in philosophy are often the most enlightening - in metaethics, for example. It would certainly be wrong to thing that these enlightening analyses are only incidentally crude and false as analyses. Rather, their crudity and literal falsity is essential to their being illuminating. We are noticing an illuminating analogy - and for an analogy, you need two different things, so the analysis which shows clearly such an analogy is bound to be crude and false qua analysis.

Saturday 17 December 2016

What Was My Problem?

From notes made early in my PhD research:
The central flaw in much of what I have written is that it has the unintended appearance of giving a kind of unexpected grounding for modal discourse. Perhaps it also might look as though what I'm saying might change our evaluative criteria, cast doubt on earlier beliefs about what's possible, etc. All of this has to be avoided. But it isn't satisfactory to simply insist 'No no no, that's not what I'm doing at all' - this has to be made evident. And the way to do that is to be better (more effective) at what I'm really doing. Very often, my problem is that I don't know what my problem is. I have to take it easy about that, and just look for frontiers where they arise.
I think I ended up avoiding this flaw. It gradually became clear that the problem to which I had a solution in inchoate form (now it's hopefully in a clear form) was not about the grounds of modality in general, but rather about the particular, partly-themselves-modal grounds, of the modal notion of subjunctive or metaphysical necessity as it applies to propositions. More specifically, about whether and how semantics comes into the picture. (A proposition is necessary iff it is or is implied by a proposition which is both inherently counterfactually invariant and true, and it makes sense to think of inherent counterfactual invariance as a broadly semantic property.)

Monday 14 November 2016

On Carnap's 'Empiricism, Semantics, and Ontology' - Towards a More Nuanced View

Below are some notes on the first two sections Carnap's classic paper 'Empiricism, Semantics, and Ontology'. (Carnap's ideas in this paper have been very influential, and there has been a recent flurry of interest in them, as reflected in the 2016 publication of a volume entitled Ontology After Carnap. Thomas Hofweber, whose ontological project I have criticized, is a contemporary philosopher who has been very influenced by these ideas of Carnap.)

The notes below end up suggesting a more nuanced view of what is going wrong in metaphysical debates about the existence of ordinary things and numbers, according to which Carnap has correctly diagnosed that a kind of impossible jumping out of a framework is being attempted. But on the more nuanced view, this kind of jumping out is possible in some cases. (Carnap's view is that it never is, except as a potentially misleading way of switching to talk about the practical question of whether to adopt a linguistic framework.) That it is possible in some cases better explains why we so much as attempt it in the case of ordinary things and numbers.

* * *

'If someone wishes to speak in his language about a new kind of entities, he has to introduce a system of new ways of speaking, subject to new rules; we shall call this procedure the construction of a linguistic framework for the new entities in question.' - What is the status of this proposition? Is it meant to be a tautology? What does it take to be a 'new kind' of entity in the relevant sense? For in some reasonable sense it seems clear that we can begin to talk about a kind of entity which we have not previously been talking about without introducing a new linguistic framework. The framework can have, so to to speak, advance provisions for that in some cases.

'To recognize something as a real thing or event means to succeed in incorporating it into the system of things at a particular space-time position so that it fits together with the other things as real, according to the rules of the framework.' - Shades of pragmatism, or coherentism. Is 'recognize as F' a success verb here? Can't we have an idea of something which does fit well with our other current ideas but which is nevertheless the idea of something which doesn't actually exist?

Also, why a particular position? That seems false. Surely we can come to recognize the existence of something without knowing where it is. Also, the language Carnap uses here is quite unclear because while he is actually talking about changes on our end, i.e. in our linguistic representations and thoughts, he makes it sound like we are operating with the things themselves, incorporating them into a system.

- 'From these questions we must distinguish the external question of the reality of the thing world itself.' - This is a strong case for Carnap (who is talking here about the world of ordinary, observable physical objects), but one might wonder if it fails to generalize. Isn't there something special about our talk about the thing world? Carnap himself admits that the members of the thing world are 'the simplest kind of entities dealt with in the everyday language: the spatio-temporally ordered system of observable things and events'.

Couldn't it be this - the special foundational role played by talk of ordinary things - that makes it nonsense to ask whether they exist? (Or makes the question unsettlable?) Couldn't you have other cases where you've set up a framework which seems to licence certain "internal" existence statements, but where you can quite intelligibly and productively ask whether the things posited really exist at all? (And where this is not plausibly construed, as Carnap would want to construe it, as a practical question about whether to accept certain linguistic forms?)

It may be instructive to attempt to construct a clear, if artificial, example of this. (Here is a first thought, though there may well be much better examples available: a legal linguistic framework may treat the existence of a court as a basic assumption, without which the framework could not be applied. This doesn't mean we can't drop the legalese - step outside the legal linguistic framework - and ask about the existence of the court.)

Remember, linguistic frameworks can be embedded in larger linguistic frameworks. And in that way, we may be able to call the existence of the entities posited in some framework into question outside that framework, by remaining in a larger containing framework which allows us to treat the question in what Carnap would allow is a 'scientific, non-metaphysical' way. So that in the larger framework, the existence of the kind of entity in question is a question which may be answered empirically or a priori, in a non-trivial and non-metaphysical way, while in the embedded framework, the existence of the kind of entity in question is a basic assumption. I.e. something without which we can't really get off the ground with the embedded framework at all.

'The acceptance of the thing language leads on the basis of observations made, also to the acceptance, belief, and assertion of certain statements. But the thesis of the reality of the thing world cannot be among these statements, because it cannot be formulated in the thing language or, it seems, in any other theoretical language.' - Again, it seems like the thing language is a special case here, which makes Carnap overgeneralize. In the cases of less basic, less foundational frameworks, the latter disjunct 'or, it seems, in any other theoretical language' may be weak indeed.

Now Carnap turns to numbers, and again his case there is strong.

So, what I am saying is no threat to the core of Carnap's way of understanding what is wrong with metaphysical questions about the reality of ordinary things or the reality of numbers. Rather, it may lead to a nuancing of this and greater plausibility for it.

The problem isn't that you can never get outside a framework and ask about the reality of the things posited in the framework. On the contrary, you often can. And that helps explain why the attempt in the case of things and numbers is made at all.

So this more nuanced view has greater explanatory power. On Carnap's simpler view, according to which there is no such thing, ever, as getting outside a framework to ask about existence (literally, not as a disguised practical question), it is less clear why we would ever try.

Furthermore, the very idea of this going outside a framework, i.e. the very idea of what Carnap would call an 'external existence question', becomes clearer on the view I am suggesting. Rather than this mysterious thing which cannot in any possible case be done, it becomes something which can happen, and which we have examples of. On that basis, we may then argue that certain cases which bother philosophers are such that there is no properly analogous going-outside-the-framework to be done.

Wednesday 26 October 2016

Caught in the Act of Confusing Subjunctive Necessity and Apriority: The Importance of the Sprigge Quote in Naming and Necessity

One of the big questions surrounding Kripke's innovations in Naming and Necessity is the extent to which, with his doctrines about necessity and the necessary a posteriori, Kripke corrected false views about necessity, as opposed to just emphasizing a neglected notion of necessity on which 'necessary a posteriori' is a non-empty category. Also unclear is the extent to which pre-Kripkean thinkers were confusing the Kripkean notion of subjunctive necessity with other notions, or just not giving that notion much attention. It's not clear, for instance, that Putnam in 'It Ain't Necessarily So' ever invoked subjunctive necessity.

This makes the following quote from Sprigge, which Kripke uses in N&N (p. 111), particularly interesting. It seems to provide a clear case of a philosopher confusing subjunctive necessity, on the one hand, with either indicative necessity or apriority on the other hand:

The anti-essentialist says that there would be no contradiction in a news bulletin asserting that it had been established that the Queen was not in fact the child of her supposed parents, but had been secretly adopted by them, and therefore the proposition that she is of Royal Blood is synthetic. In this way the anti-internalist parries the argument of the internalist by suggesting with regard to each proposed internal property of the particular in question, that we can quite well imagine that very same particular without the property in question. For a time he is winning. Yet there comes a time when his claims appear a trifle too far fetched. The internalist suggests that we cannot imagine that particular we call the Queen having the property of at no stage in her existence being human. If the anti-internalist admits this, admits that it is logically inconceivable that the Queen should have had the property of, say, always being a swan, then he admits that she has at least one internal property. If on the other hand he says that it is only a contingent fact that the Queen has ever been human, he says what it is hard to accept. Can we really consider it as conceivable that she should never have been human? (Sprigge (1962), p. 203.)

It seems pretty clear that here Sprigge takes the possibility of the bulletin - the possibility of finding out that Elizabeth II is not actually born of royal blood - as tantamount to it being the case that things could have gone such that she was not born of royal blood.

So, this quote makes it seem almost certain to me that someone - namely Sprigge - was actually confusing subjunctive necessity with either apriority or indicative necessity. Further questions are how widespread the confusion was around the time Sprigge wrote, and whether this was a relatively new thing at the time. Is it the case that, by the time Sprigge wrote the above but not for long before that, the notion of subjunctive or counterfactual necessity was "in the air", was salient, and so this sort of confusion is a relatively short term phenomenon occurring only in the lead-up to N&N (and shortly after, while people had yet to digest Kripke)? Or is the confusion something we can find much earlier evidence of?


Kripke, Saul A. (1980). Naming and Necessity. Harvard University Press.
Putnam, Hilary (1962). It ain't necessarily so. Journal of Philosophy 59 (22):658-671.
Sprigge, Timothy (1962). Internal and external properties. Mind 71 (282):197-212.

Friday 14 October 2016

Distributed Verification: Semantic Deference Needn't Bottom Out in a Non-Deferential User

Woodward in 'Reference and Deference' writes:
Linguistic deference and conceptual deference are widespread phenomena. However, some philosophers say that deferring has to stop at some point, for if everyone were deferential with respect to a given word or concept no one would ever succeed in attaching a definite content to it. That thesis is the stimulus for this paper.

Fodor certainly holds the thesis. In his latest book Concepts, Fodor (1998, p. 154) says, ‘Adherence to conventions of deference couldn’t be a precondition of conceptual content in general, if only because deference has to stop somewhere; if my ELM concept is deferential, that’s because the botanist’s isn’t’. (cf. Fodor 1994, p. 33).
That thesis, or almost that thesis, is the stimulus for this blog post too. But my target is different from Woodfield's. His target - that which he argues against - is literally the thesis that deferring has to stop at some point, in some sense. My target is rather the thesis that deferential concept use can only terminate successfully when someone has the concept and uses it non-deferentially.

So again, while Woodfield's paper may seem to be upholding the same sort of view as I am here, I don't think it is the same. His point seems to be that we need not think that deference must stop, in that a bunch of experts who are good at different things may go on being disposed to defer to each other indefinitely. But my point here is, not that it may sometimes never be finally settled whether a has P, but that it is possible for such a question to be settled without it being the case that any single person's use of 'has P' is non-deferential. 

Imagine three chiefs in a tribe, each one good at certain verification tasks. Everyone in the tribe agrees that for an animal to count as having property P, it needs to appear Xish to Chief A, Yish to Chief B and Zish to Chief C. 

This is, in a way, especially clear if 'has property P' just means 'appears Xish to Chief A, Yish to Chief B and Zish to Chief C'. But that this sort of situation could arise without such a disjunctive meaning having to do with three different people's phenomenology is worth realizing as well, since it may help us see to what extent this sort of distributed verification may happen with more normal, real-world language and concepts.

When someone in this community wants to know if an animal has P, they may put it to the chiefs. In a case where the verdict ends up being that the animal does have P, we might imagine the process going as follows. The questioner asks the three chiefs, who approach the animal together, perhaps from different angles. Chief A says 'It has P if Chiefs B and C have no objection', Chief B says 'It has P if Chief C has no objection', and then Chief C just nods and says 'OK, I guess it has P then!' and everyone is happy.

This is just a quick, initial attempt to show that this kind of 'distributed verification' is possible, and that therefore semantic deference needn't bottom out in a non-deferential language user.


Fodor, J. (1994). The Elm and the Expert. Cambridge, MA: MIT Press.
Fodor, J. (1998). Concepts. Oxford: Clarendon Press.
Woodfield, Andrew (2000). Reference and deference. Mind and Language 15 (4):433–451.

Friday 30 September 2016

Feedback please: Thesis draft, Necessity and Propositions

Here is a draft of my PhD thesis (updated 29 OctNecessity and Propositions. It contains my best treatments so far of some of the topics covered on this blog over the last five or so years. I have a bit more polishing to do and will be handing it in around mid-October. I still have a chance to make substantive changes, so please give me any feedback you can, substantive or otherwise! (Either comment here, or email me at '' without the numeral.)

As I make final changes I will keep re-uploading it to the same location.

Thursday 29 September 2016

Are Meanings 'Individual Things'? An Important Unclarity in Lycan

I have recently been enjoying some of Lycan's papers, as well as his Philosophy of Language: A Contemporary Introduction. In Chapter 5 of the latter he writes:

In stating the foregoing meaning facts, I have at least half-heartedly tried to avoid “reification” of things called meanings; that is, talking about “meanings” as if they were individual things like shoes or socks.

'Like shoes and socks' how, though? The problem is: what does this mean?

Lycan then introduces the idea of 'entity theories':

Philosophers have made an issue of this. Let us use the term “entity theory” to mean a theory that officially takes meanings to be individual things.

And he goes on to contrast such theories with - you guessed it - 'use' theories, with the later Wittgenstein as the paradigm.

I think this is an unclear and misleading contrast. It is unclear what it takes to be an 'entity' or an 'individual thing'. The examples of shoes and socks may suggest that this notion is something like that of a physical object, or a 'concrete particular'. But that can't be right, as Lycan wants to count Fregean sense theories, or Moore's theory of propositions, for instance, as 'entity theories', but Fregean senses and Moorean propositions are not supposed to be physical, concrete things. Also, how are we to know what is official and unofficial? That distinction seems fishy here.

This contrast is misleading, I think, because it may suggest that the idea that meanings - or an aspect of them at least - should be thought of as roles in language systems, or uses of signs, commits one to some dark doctrine about these roles or uses not being 'individual things'. Which, as I have suggested, has no clear meaning. This may then marginalize this sort of role/use idea about meaning, for example by making it look as though it is automatically in contradiction with any technical semantic theory which maps expressions to entities of some sort.

I suggest that the real point in this neighbourhood, regarding a role/use conception of meaning, is not that on such a conception, meanings aren't entities, or individual things - whatever that means - but that they are, speaking loosely, 'things' in a quite particular, easy to misunderstand sense. In Wittgensteinian terms, the grammar of expressions like 'the meaning of that utterance' must be attended to, and our understanding of it not simply modelled on that of expressions which function very differently, say, 'the bearer of that name' or 'this shoe'.


Lycan, William G. (1999). Philosophy of Language: A Contemporary Introduction. Routledge.

Monday 1 August 2016

Denying the Conditional Premise: An Underrated Response to Skeptical Arguments

(This is a more focused re-write of a post from a couple of years ago, with better coverage of the literature.)

1. Introduction

Much ink has been spilled on skeptical arguments like the following:
  1. If you're a brain in a vat then you don't have hands
  2. You don't know that you're not a brain in a vat
  3. Therefore you don't know that you have hands
There are many variations on this sort of argument, and many issues have been raised about it, for example the issues of the closure of knowledge under implication, and the closure of knowledge under known implication.1

Here I will focus on the conditional premise part of this sort of argument. That is, on the premise which links a hypothesis according to which you are living in a simulation (e.g. the hypothesis that you are a brain in a vat (BIV)), to a seemingly-crazy hypothesis which flies directly in the face of things we normally think we know (e.g. the hypothesis that you don't have hands). Perhaps surprisingly, the truth of these premises is typically – we will consider a couple of exceptions below – taken for granted in contemporary discussions of such skeptical arguments.

For instance, Steup (2006, section 1) writes:

According to the BIV Hypothesis, you are a mere BIV without a normal body. This of course means, among other things, that you don't have hands.

Steup then goes on to consider five known kinds of responses to skeptical arguments. None of them, however, involves questioning (1), or questioning Steup's claim that '[t]his of course means, among other things, that you don't have hands'.

In this essay I want to argue against these conditional premises. I will try to be fairly non-technical and to avoid bringing in any very particular theoretical framework. I will focus on (1) in particular for the sake of definiteness, but the considerations will generalize in an obvious way to many similar conditionals.

In arguing that (1) and the like are not true, I am furnishing a way of avoiding the repugnant conclusions of skeptical arguments like the above without having to show that we do somehow know that we are not BIVs. We should instead, I say, just deny their conditional premises. This seems pre-theoretically attractive to me – it does intuitively seem to me that I do know that I have hands and that I do not know that I'm not a BIV. Or more carefully perhaps, and from a broadly contextualist perspective on knowledge-ascriptions2, it seems to me that there are contexts in which 'I know I have hands' comes out true while 'I know I'm not a BIV' comes out false.

Note that (1) and the like are generally supposed to be accepted readily, as though they were obvious (recall the Steup quote above). They just appear in skeptical arguments as premises which we're meant to accept without argument. Once you start scrutinizing (1) and the like as I propose, this can begin to seem rather odd. It can become hard to imagine what (1) ever had going for it. So, before arguing against it, let us first ask the question: why might (1) seem true?

Silly as it sounds – silly as it is – the answer appears to be something like this: when (1) strikes us as true, we are as it were picturing a brain sitting in a vat, and observing that there are no hands in that picture. Or we are picturing a brain sitting in a vat, and a mad scientist tending it, and noticing a striking contrast between the two figures – the scientist-figure has a body and hands, whereas the other figure is just an organ (in a vat). Something along those lines.

In this essay, I will argue that, by contrast, the denial of (1) has a good deal going for it. After first, in section 2, criticising and setting aside a superficial objection to (1), I will offer a volley of better arguments against it, beginning in section 3. In section 3 I will object that the question of whether a BIV has hands or not is better thought of as marking a different contrast from that between the BIV and the scientist above – a contrast such that some (possible) BIVs have hands and others do not. A possible doubt about this objection, which I will not try to allay in this essay, will lead us in section 4 to another objection based on it, which avoids the doubt. This objection, however, requires that when a BIV says 'I am a BIV' they are saying something true (however unknowable it might be to them). As natural as it is to accept this, it is contradicted by a famous argument of Putnam's, an argument designed to show that we are not BIVs. Accordingly, in this section I also examine and criticize Putnam's semantic ideas about 'I am a BIV' as said by a BIV, defending my objection against the threat from Putnam's argument. Then, beginning in section 5, I turn to a series of more intuitive arguments, designed to change the attitude of someone who is inclined to think (1) is true. In section 5 I make a case against (1) involving consideration of what is, and more importantly what isn't, implied by ordinary statements referring to hands. The idea here is to snap out of a false way of looking at such statements which we fall into when philosophizing about skepticism. In section 6, I contrast “normal” BIV scenarios with ones in which we are worse off epistemically, in order to motivate a view of “normal” BIV scenarios according to which their obtaining does not preclude our having hands. In section 7, I will suggest a reframing of the BIV hypothesis as a scientific one, and argue that from this point of view, the natural thing to do is to reject (1). This last suggestion will be seen to be essentially the position of Chalmers (2005), and therefore further supported by his arguments.3 I conclude briefly in section 8.

2. A Superficial Objection to (1) Rejected

Here I want to consider and put aside one particular line of attack on (1), to be found in Roush (2010). It is an almost comically literal-minded objection, which I found when I was searching the literature for previous attempts at calling propositions like (1) into question. Roush (2010) argues that it is not true that if you're a brain in a vat then you don't have hands, on the grounds that you might be a brain in a vat with hands just stuck on (!) – that is, where there are attached hands in the environment which contains the brain and the vat (as opposed to the environment simulated for the brain). Maybe the hands are just stuck on with glue and dangle there, or maybe they are delicately connected up with the brain, making for a queer straddling of two “worlds” (or environments, or levels of reality) on the part of the BIV.

There is something very frustrating about this objection. It is frustrating, I think, because if you just accepted this objection, deciding on its basis that (1) is false, and then walked away, you would have lost a valuable philosophical opportunity to understand (1) better. Furthermore, even if Roush's objection shows (1) to be false, the skeptical argument can easily be patched up by replacing (1) with 'If you're a brain in a vat without appendages as envisaged in Roush (2010), then you don't have hands'. Thus if we want to find objections to (1) in order to disarm skeptical arguments which threaten our putative knowledge that we have hands, we had better keep looking. We want an objection that is not so easily met with a patched conditional premise. (This is not to concede that the objection does show (1) to be false, by the way. For instance, we may ask whether a BIV with the envisaged appendages really counts as 'having hands', or whether this is really the best candidate meaning for 'having hands' in connection with a BIV.)

3. A Better Deserver of 'Having Hands' vs. 'Not Having Hands'?

We picture a BIV, and there are no hands in the picture. Then we picture a scientist tending the BIV and see a contrast between the figure of the scientist and the BIV-figure. And with this in mind, we might be tempted to say 'The BIV doesn't have hands and the scientist does'.

OK. But consider a different situation, in which we have two BIVs. It doesn't matter whether or not they are plugged into the same simulation. What does matter is that, in their lives in their simulation(s), one of them is an anatomically normal human, while the other has been in an accident and lost their hands. Mightn't we, if this was the first case we had considered, have been tempted to say 'One BIV has hands, the other does not'? And if we would be right in so saying, then we would be wrong to say (without shifting the meanings of relevant terms) that if you're a brain in a vat, you don't have hands; the first BIV would then be a counterexample to (1).

If we allow that we would be correct in saying, of the envisaged scenario, 'One BIV has hands, the other does not', this gives us an objection to (1). On this objection, 'has hands' vs. 'does not have hands', when applied to BIVs, is correctly used to mark this contrast, between BIVs like the first one and BIVs like the second one. Not the contrast between a BIV and a scientist tending it.

Here it might be objected that it would not be correct to say, unqualifiedly, 'One BIV has hands, the other does not' – rather, one would, to be both right and completely explicit, have to say something like 'One BIV has hands in its simulated environment, the other does not'.

In the present essay, I want to go along with – without endorsing – this objection to the present objection to (1), and use the present objection to (1) as inspiration for another objection, an objection which focuses on the truth-values of propositions uttered by a BIV in their simulated environment rather than on propositions we, standing outside a hypothetical scenario, might formulate about it. That is not to say there are no prospects for sticking with the present objection to (1) and arguing that the objection to it which we have just considered is mistaken – only that we will not pursue this here.

4. The BIV-or-Parity Argument

It may be that, of our first and second BIV above, we can't say with literal correctness that the first has hands and the second does not. But we can still ask about things the BIVs may say, in their simulations. And we could reason as follows: If the first BIV says, in the simulation, 'I have hands', they are, in the simulation, saying something true. And surely if they say, in the simulation, 'I am a BIV', they are, in the simulation, saying something true (even if they could never know it to be true). And thus, if they said 'If you're a brain in a vat then you don't have hands', they would be saying something false – something to which their very case is a counterexample. And if that's right, how could (1) fail to be false? How could our situation differ from the situation of the BIV in question in such a way that (1) for us is true, whereas their utterance – in the simulation – of 'If you're a brain in a vat then you don't have hands' – is not? I can see no way.4 So, I suggest the following overall argument. We are either BIVs or we are not BIVs. If we are BIVs, the above considerations about the truth-values of utterances made by an anatomically-normal BIV apply directly to us. If we are not BIVs, parity suggests that (1) for us has the same truth-value as the same sentence uttered by a BIV. Either way, (1) is false.

Now, the above reasoning seems natural, but of course it could be challenged. One way it could be challenged would be to follow Putnam's notorious (1981) in saying that, when the BIV says, in their simulation, 'I am a BIV', they are saying, in their simulation, something false, contra the above reasoning.

I do not have space here to lay out Putnam's arguments at length, but I think it is incumbent upon me to argue that Putnam is wrong on this point. I will now try to do this briefly and non-technically, but in a way that cuts quite deeply, perhaps more so than technical criticisms focusing on what might be non-essential features of Putnam's argument or reconstructions thereof. (For an overview of the literatue on Putnam's argument cf. Brueckner (2016).)

Putnam begins with a causal theory of reference, according to which what you're talking about when you say something is what stands in an appropriate causal relation with your utterance. He argues, from the causal theory, that since a BIV could have no causal contact with the brain they are, and the vat they are in, they could not be talking about that when they say 'I am a brain in a vat' – rather, their utterance is, according to Putnam, about 'vats-in-the-image', 'or something related (electronic impulses or program features)'5. And since they, the utterers, are not vats-in-the-image, i.e. not vats belonging to their simulation, nor the relevant 'related' things, what they thus say comes out false. Putnam goes on to argue, on this basis, that we are not BIVs, but we will stop here and just criticize this lemma – that a BIV saying 'I am a BIV' says something false – since the denial of that is all we need for our argument.

There are lots of things about this we could argue with – the idea that the BIV's talk might literally refer to electronic impulses or program features may seem crude and objectionable, for instance – but I will confine myself to a couple of key points.

Firstly, note that singular reference – reference to particular objects – isn't what is in question here. We are dealing with general terms like 'brain' and 'vat'. And what Putnam seems to be insisting on, in light of his causal theory of reference, is that, in order to really be about brains or vats, my talk needs to have an appropriate causal connection with some brains, or vats. So, going along with this way of thinking about what is required for talking about a kind of thing, in order for a BIV to think or say they are a BIV, it would seem that their thought or talk doesn't have to be causally connected with the particular brain they are or the particular vat they are in. It just has to be connected with some brains and some vats.

Now, why can't there be a general category marked with the word 'vat' which includes as members both “vats-in-the-image” - vats in simulations – and vats outside simulations? (And likewise for 'brain'.) I think we should say that there can be such a category. Consider things like happiness and intelligence: a BIV with a rich life is surely acquainted with these things, and causally connected with exemplars of them – and so they can have a category, for example marked 'expressions of happiness', and this category would include both things in their simulated environment and any appropriate things outside the simulation. And so Putnam's argument falls down here, by implicitly holding that the relevant reference classes – the 'brain' class and the 'vat' class – can only include things in the utterer's environment (or “level of reality”). Once we see this is not so, we can go along with Putnam's basic causal-theoretic starting point, but maintain that there is nothing stopping BIVs thinking they are BIVs, because they can form categories – by means of causal connections to brains and vats in their environment – which manage to include the brain they are and the vat they are in, despite those particular instances not being in their environment.

Now let us try to get a more positive sense of what is the matter with Putnam's argument, rather than just poking a hole in his reasoning. I want you to step back a bit, and just note how implausible and crude Putnam's interpretation of the BIV's utterance 'I am a BIV' is; it's supposed by Putnam to assert something which to the BIV would be obviously wrong – namely, something like: that they are brains in their environment in vats in their environment. And yet a reflective BIV might not find their utterance of it obviously wrong at all – on the contrary, it would be natural for them to regard it as something which it would be difficult or impossible for them to know the truth about. This suggests that something has gone awry. At a very general level, we may say that Putnam's problem is that he has inappropriately treated the language-game of talking about being a BIV as being just like an ordinary one about things in our environment. But it is plainly not that. Language, we might say, is playing a new trick here.6 We may not be able to come up with a theoretical understanding of this trick which would satisfy Putnam, but that does not mean he gets to falsify it.

So, I suggest that Putnam has not refuted the natural view that when a BIV says 'I am a BIV' they say something true, albeit something they may never be in a position to know. And thus the BIV-or-parity argument does not fail for that reason.

You may still be unconvinced, though, about the initial premise, i.e. that when an anatomically normal BIV – I mean their anatomy in the simulation, of course – says 'I have hands', they are saying something true. Accordingly, I will present further objections to (1) and the like which are supposed to convince you of this too, rather than just taking it as a premise. The general tendency of these arguments is to appeal to our common sense, as against the philosophical mood we are liable to be put into by skeptical arguments. (That this is a distinct mood is not something I am supposing to be obvious in advance, but if we are responsive to the appeal to common sense, I think we can see, in retrospect, that it was a distinct mood.)

5. Everyday Statements About Hands, And What They Do and Don't Imply

Consider statements made in ordinary, everyday conversation, statements which intuitively seem to imply that the utterer has hands. I want to urge that, intuitively, these seem not to imply that the utterer is not living in a simulation. That is, I think that is how it appears if we just regard these utterances with a normal, common sense attitude, instead of letting the skeptical argument put us in a philosophical mood in which our attitude changes and 'language goes on holiday'7. I suggest we accept these appearances, and conclude that (1) and the like are false.

For example, suppose someone asks me to help them with something and I say 'OK, one second - I'm just washing my hands'. This statement – that I'm washing my hands – surely implies that I have hands. Furthermore, I find it very intuitive – regarding the case from a common sense point of view – that it does not imply that I'm not living in a simulation, or that I'm not a BIV; that simply isn't at issue at all. That seems, I want to urge, quite independent of – extraneous to – the truth of what I said.

Going along with this: having hands is compatible with it not being the case that I'm not a BIV. And so, having hands is compatible with my being a BIV. And so it can't be true that if you're a BIV then you don't have hands.

6. That's Not A Nightmare. This Is a Nightmare!

The key intuition appealed to in the previous section – that my ordinary statement does not imply that I'm not living in a simulation – can, I suggest, be bolstered by thinking a bit about the space of different scenarios in which I am living in a simulation. Then we begin to see that it is possible to take an attitude to many of these scenarios which is quite unlike regarding them as epistemic nightmares, i.e. situations in which we're in really bad shape epistemically – where much of what we ordinarily think we know fails to be true. We can bring this out by contrasting “normal” scenarios in which we are in a simulation to what, by comparison, are the really nightmarish scenarios in which we are in a simulation. (Compare section 3, where we contrasted anatomically normal (in their simulation) BIVs with those who have been in accidents (in their simulation).)

Certainly we can imagine simulation-scenarios which are epistemic nightmares. We may be BIVs whose tending scientists are engaging in all kinds of foul play, planting false memories and moving things around on us. Also diabolical would be if some or all of the apparent agents we are interacting with are not sentient, or not as fully sentient as we think. I don't so much mean that they may not be constituted the way we are, or the way we think they are – after all, multiple realizability might be the case – but rather that maybe all there is to these agents is what's required to generate our interactions with them. Corners may be cut, so to speak – when we think they're off by themselves having a rich mental life, perhaps often nothing of the sort is true. But nightmarish scenarios like this are clearly a special subset of all simulation scenarios; in many of the latter, by contrast, I suggest that we may not be wrong about much of anything (or rather, not about anything to which the unknown fact that we are in a simulation would be relevant). It just might be the case that, unbeknownst to us, there is a higher level of reality “hosting” the one we inhabit, and this level may involve brains in vats.

Now, this of course raises the question: well, what about skeptical arguments which appeal to those really bad scenarios? Can't the skeptical arguments I am talking about just be patched up in light of this, thus making your criticisms no better than that of Roush, whom you criticised in section 2 for giving a superficial, easily avoided objection?

To this, I reply that, no, there is an important difference here. In the present case the 'patching up' is more complicated, and different BIV scenarios threaten different bits of what we normally think we know. It may be fairly easy to specify a scenario where certain supposed historical events in the simulation did not happen in the simulation, but the traces of them were put into the simulation in some other way. It may be fairly easy, but maybe a bit harder, to specify a BIV scenario where a BIV who hasn't been to France (in their simulation) is deceived about there being an Eiffel Tower (in their simulation). Harder still, but maybe doable, would it be to specify a scenario in which what a BIV takes to be other persons whom they know well are not actually fully persons, or do not always exist. As to what a BIV scenario where you are BIV who falsely thinks they have hands might really look like, I am not sure. I do not want to claim that no such scenario exists. The point is rather that, on the point of view I am advocating here, this would have to be quite a specific scenario – it merely being a scenario where you are a BIV doesn't automatically do the trick. This is, I think, a better, more nuanced way of thinking about BIV scenarios in relation to knowledge.

In further support of this viewpoint, I want to give one more suggestion, in the next section: that we reframe the BIV hypothesis as a broadly scientific one, rather than thinking of it as something like a threatening, sinister element in a story.

7. Reframing the BIV Hypothesis as a Scientific One

There is no need to respond to the news that you're a brain in a vat by revising your belief that you have hands. Why not treat the news instead as telling you, among other things, something new about your hands (and everything else in your environment), namely that they are “hosted” at a higher level of reality, or speaking crudely, are constituted by electrical impulses or program features. I say 'crudely' because the relation in question is obviously not the normal one of constitution from normal physical inquiry. Physics can be done in a simulation, too, and facts about the simulation being a simulation need not be regarded as belonging to that discipline. Nevertheless, I think it is quite natural to follow this suggestion and regard the BIV hypothesis as, in a broad sense, a scientific one. This seems to be a legitimate point of view. And once we take this point of view, it becomes natural to think of the hypothesis as one about the nature – in some sense – of your hands (and everything else in your environment), and thus not as a hypothesis which rules out your having hands. Compared with looking at these scenarios as something like sinister, threatening elements in a story, and then in that mood jumping to the conclusion that we don't have hands if those scenarios obtain, the point of view I am advocating seems the more clear-headed.

This last suggestion, that we regard BIV scenarios as scientific hypotheses, is substantially the same as Chalmers' suggestion in his (2005) that the hypothesis that we are in the same sort of situation as the main character Neo in the movie The Matrix is a metaphysical, rather than a skeptical hypothesis.8 (I prefer to use 'scientific' as the replacement category for 'skeptical', since I think we have a clearer idea of what science is, and of its successes, than we have of metaphysics. But presumably metaphysics is a kind of science, in a broad sense of 'science', so this is not a major disagreement.) Chalmers writes:

I think the Matrix Hypothesis should be regarded as a metaphysical hypothesis [...]. It makes a claim about the reality underlying physics, about the nature of our minds, and about the creation of the world. (Chalmers (2005), section 3.)

His argumentative strategy is (i) to formulate a 'metaphysical hypothesis' with three components, teased out in the way suggested by the last sentence quoted above, (ii) to argue that none of these components threatens to radically undermine what we think we know, and (iii) to argue that the metaphysical hypothesis is equivalent to the Matrix Hypothesis, in which case the latter does not radically undermine what we think we know either. Along the way, he responds to several possible objections.

In this section, I have simply outlined the idea of reframing the BIV hypothesis as a scientific one, and argued that it seems legitimate and more clear-headed than thinking of it as a threatening, sinister element in a story, i.e. the viewpoint we have when we think of it as a 'skeptical' scenario. Chalmers, modulo the minor differences between his discussion and mine outlined above, goes further on this front. Conversely, his discussion does not contain the earlier considerations of the present essay, such as the 'other contrast' argument of section 3, the 'BIV-or-parity' argument of section 4, the appeal in section 5 to common sense regarding everyday statements about hands, or the argument from contrast with really bad epistemic situations of section 69. Thus Chalmers' discussion and mine here are mutually supportive.

8. Conclusion

I have tried in this essay to make a good, multi-pronged case against (1) and similar conditionals, which feature as premises in much-discussed skeptical arguments. I hope I have convinced you that (1) and the like are false. Failing that, I hope I have at least convinced you that they are seriously open to question, not something which we should say 'of course' or 'obviously' about, as we saw Steup (2006) do.


Bouwsma, O. K. (1949). Descartes' evil genius. Philosophical Review 58 (2):141-151.

Brueckner, Tony. (2016). Skepticism and Content Externalism. The Stanford Encyclopedia of Philosophy (Summer 2016 Edition), Edward N. Zalta (ed.), URL = <>.

Chalmers, David J. (2005). The matrix as metaphysics. In Christopher Grau (ed.), Philosophers Explore the Matrix. Oxford: Oxford University Press.

Lewis, D.K. (1996). Elusive knowledge. Australasian Journal of Philosophy 74 (4):549 – 567.

Luper, Steven. (2016). Epistemic Closure. The Stanford Encyclopedia of Philosophy (Spring 2016 Edition), Edward N. Zalta (ed.), URL = <>.

Putnam, H. (1981). Brains in a Vat, in Reason, Truth, and History. Cambridge University Press.

Roush, S. (2010). Closure On Skepticism. Journal of Philosophy 107 (5):243-256.

Schaffer, J. (2015) Lewis on Knowledge Ascriptions, in A Companion to David Lewis (eds B. Loewer and J. Schaffer), John Wiley & Sons, Ltd, Oxford, UK.

Steup, Matthias. (2006). Knowledge and Skepticism. Supplement to 'The Analysis of Knowledge'. The Stanford Encyclopedia of Philosophy (Spring 2006 Edition), Edward N. Zalta (ed.), URL = <>.

Wittgenstein, L. (1953). Philosophical Investigations. Oxford: Blackwell.
Wittgenstein, Ludwig (1966). Lectures & Conversations on Aesthetics, Psychology and Religious Belief. Oxford: Blackwell.

1Cf. Luper (2016, section 5) for an overview of closure in relation to skepticism.

2. Cf. Lewis (1996). For an attempt to elaborate Lewis's core ideas about knowledge ascriptions more thoroughly and rigorously, cf. Schaffer (2015).

3. An important precursor to the present discussion and that of Chalmers (2005) is Bouwsma (1949). Bouwsma discusses, not a scenario in which we are living in a high-tech simulation, but an older kind of scenario in which an evil demon with supernatural powers is trying to deceive us. I have not tried to engage directly with Bouwsma's discussion here, since the evil demon scenario seems to me importantly different in a number of ways from a BIV scenario (and such differences aren't my focus here). Also, Bouwsma's piece is written in a literary, exploratory style, so that explicit commitments and arguments are not to the fore. Nonetheless, it is important to note that his piece exhibits, more than half a century earlier, the same overall tendency as the present discussion and Chalmers', i.e. to suggest that what may seem like epistemologically very threatening scenarios at first glance and in a certain philosophical mood, are more properly regarded as not so threatening.

4. At least, I can see no way which doesn't turn on us not being BIVs, not living in a simulation – and in that case, we wouldn't be able to know (1) without first knowing that we are not BIVs, in which case the skeptical argument could no longer be run.

5. (Putnam (1981), p. 15).

6. The phrase comes from Wittgenstein (1966), p. 1.

7. Wittgenstein (1953), section 118.

8. It is easy to miss Chalmers' piece when searching the literature for objections to (1), since Chalmers discusses, not the BIV scenario famous in recent philosophy, but the similar scenario depicted in the movie The Matrix (substantially the same as a BIV hypothesis, except Neo's brain outside the simulation is lodged in a body), and he doesn't explicitly frame his essay as an attack on the conditional premises of skeptical arguments, even though that is what it amounts to. (All this is in keeping with his piece having been written for a popular audience.)

9. Chalmers does touch on (Matrix-style counterparts of) what I in section 6 called 'really nightmarish scenarios in which I am in a simulation'. (In his section 5 he writes that '[t]here may be some respects in which the beings in a matrix are deceived. It may be that the creators of the matrix control and interfere with much of what happens in the simulated world.') But Chalmers does not touch on this in the service of a positive argument, by way of contrast, against (1) and the like. Rather, he discusses it defensively, as a possible threat to his claim that the Matrix Hypothesis is not a skeptical hypothesis; his point is just that this is orthogonal to the issue of whether you're in a matrix – being in a matrix doesn't by itself mean you're radically deceived, and the sort of 'interference' in question could also happen in life outside of a simulation.

Thursday 7 July 2016

Reply to Adams and Clarke, and their Rejoinder

My recent Logos & Episteme paper, 'Two New Counterexamples to the Truth-Tracking Theory of Knowledge', has come in for criticism by Fred Adams and Murray Clarke. (Here is my original blog post about the paper.)

A recent issue of the journal contains a discussion note by Adams and Clarke entitled 'Two Non-Counterexamples to Truth-Tracking Theories of Knowledge'. Peter Baumann drew my attention to this and discussed it with me. I have also been happy to learn that Adams has given presentations where he talks about my paper and what he thinks is wrong with it.

The latest issue of the journal contains my reply to them, as well as a rejoinder by them.

The following is in response to their rejoinder:

Regarding the first counterexample, I am beginning to consider the possibility that the real lesson of our disagreement over it is that there are two possible concepts of knowledge which disagree about this case. Perhaps some people have one of these concepts, and some have the other, but this hasn't become clearly evident yet. Intuitively, I think that if a belief, even if it be true and truth-tracking in Nozick's sense, rests on a delusion in such a way that the delusion continues to be associated with it, and in such a way that if the delusion were removed, the belief would be relinquished, then that belief doesn't count as knowledge. If you have such a belief, I feel, you do not possess the truth about the matter in question, since your belief can be taken away from you just by correcting a delusion that you have. Adams and Clarke do not agree, and claim that everyone they have put the question to is on their side. I have certainly had people on my side too. So perhaps it is time to consider the possibility that there are two different concepts of knowledge here, and perhaps neither party is misapplying their concept in judging the example.

(Also, it may not be simply that some people have one concept of knowledge and other people have another. Some people, or even most, may have both. Or be disposed to form either (i.e. they may, in advance of considering this type of case, have just one concept which is in some sense indeterminate with respect to the case). Perhaps when I am talking to someone, urging the case as a counterexample, charity makes them select the concept of knowledge which behaves as I maintained in my original article, and perhaps when Adams or Clarke are talking to someone, urging their contrary judgement about my case, then charity makes their audience select the concept of knowledge which behaves as they maintain in their reply to me.)

Regarding the second counterexample, their latest argument seems to me very weak. In short, they contend that 'it seems intuitively likely that if p weren’t true, it might not be the case that Nutt speaks the truth regarding p [sic]' (p. 229).

This talk about what is likely true of a partially specified scenario is methodologically flawed. All I require is that there is a possible scenario, however unlikely, in which, if p weren't true, then Nutt - their name for the neighbour in my example - would still speak the truth about p, telling me that it is false. And this is the scenario I have tried to describe, by emphasizing that Nutt had a counterfactually robust desire - and ability, I might have added - to have me believe the truth about whether p is true or not. And my idea was that this desire and ability is counterfactually robust with respect to whether or not p is true. Surely this is possible. And in that case, it seems to me, Nozick's conditions are fulfilled and yet I do not have knowledge. That there is also a possible case nearby which doesn't make trouble for Nozick's theory is irrelevant.

Toward the end of their rejoinder, they seem to fall again into the misunderstanding of Nozick's theory that I tried to ward off in my reply:
[i]f one is to know something about tax law from a tax lawyer, it had better be the case that the tax lawyer would not say “p” about tax law unless p. (p. 230)

It looks here as though they mean that, if someone is to know something about tax law from a tax lawyer, it had better be the case that the tax lawyer would not assert any proposition about tax law unless it were true. As it happens, I am inclined to think this is false. But the point is that this requirement is not part of Nozick's theory. What Nozick's theory requires is that, to know something about tax law from a tax lawyer, it had better be the case that the tax lawyer would not assert that very thing unless it were true. And this is clearly a weaker requirement.

So, what Adams and Clarke say here does not succeed in neutralizing my counterexample to Nozick's theory. And their justification for saying it is cryptic and strained. They write:
Haze says that we are going rogue, and not staying true to Nozick's conditions. But as every constitutional lawyer knows, the letter of the law does not cover every application to every case. Some interpretation is required. Nozick's theory does not anticipate Haze's attempted counterexamples. But it is not hard to figure out how to apply the theory to the example and it goes as we suggest. (p. 230)

What does this claim, that 'Nozick's theory does not anticipate Haze's attempted counterexamples', mean? I don't really understand this, but it seems weaselly to me.