SORITES, ISSN 1135-1349

Issue #14 -- October 2002. Pp. 57-62

Copyright © by SORITES and Brian Garrett

Cartesianism and the Private Language Argument

Brian Garrett



One of the main reasons for interest in the «private language» debate is the assumption that the impossibility of such a language has significant implications for the philosophy of mind. In particular, its impossibility has been thought to undermine the Cartesian Model of how natural language sensation words get their meaning.Foot note 5_1 According to this model, a sensation word, such as `headache' or `tickle', gets its meaning in virtue of an act of `inner' association or ostensive definition. Even though you and I use the same English word (e.g., `headache') what I mean is defined with reference to my headaches, and what you mean is defined with reference to yours. I argue that this model is not undermined by the private language argument. Further, this model is normally thought to imply that the meanings of sensations words, so defined, are logically private, intelligible only to their user. I argue that this assumption is false.


First some comments on Wittgenstein's private language argument(s). At #202 of the Philosophical Investigations Wittgenstein offered a condensed version of the private language argument explicitly presented at #258. At #243, the issue of private language is raised again. It is crucial to be clear about the sense of `private' in this and other passages. Wittgenstein's concern is with whether there can be a logically or necessarily private language, a language necessarily intelligible to only one person.Foot note 5_2 The way Wittgenstein approaches the issue is to ask whether someone could invent a language in which words «refer to what can only be known to the person speaking; to his immediate private sensations. So another person cannot understand the language.» (#243)

One point needs to be noted about this passage (and here I am indebted to E. J. Craig's excellent «Meaning and Privacy»Foot note 5_3). Craig argues plausibly that the `So' actually denotes a fallacious inference (p. 128). From the fact that a language refers to «what can only be known to the person speaking» it does not follow that «another person cannot understand» it. This follows only on the assumption that A understands B only if A knows the objects B is referring to, and Craig rejects this assumption (pp. 130 -- 1). Craig takes Wittgenstein to have unwittingly given two definitions of `private language' (viz., «what can only be known to the person speaking» and «what is intelligible only to the person speaking»), and regards the former definition as the more fruitful one. The interesting question then becomes whether a public language might also be private, in this sense of `private'.


Section #257 has been thought by some to harbour a self-contained argument against private language.Foot note 5_4 There Wittgenstein imagines a putative private linguist, who presumably has never acquired a public language, attempting to define his sensation words by inner ostension. He writes: «When one says `He gave a name to his sensations' one forgets that a great deal of stage-setting is presupposed if the mere act of naming is to make sense.» However, three reasons tell against this `stage-setting' argument.

First, the argument is at best suggestive. We need to be told how it is possible for us to have or acquire the necessary stage-setting and, correlatively, why it is impossible for a private linguist to have or acquire such stage-setting.

Second, it is generally agreed that a socially-isolated-from-birth Crusoe, alone on his desert island, can, if sufficiently ingenious, name and describe aspects of his physical environment. But, in that case, he must have in place whatever stage-setting is required for naming, and it is hard to see why such stage-setting cannot be available to the private sensation linguist. If the requisite stage-setting does not require the presence of others, as the Crusoe case demonstrates, why should the private sensation linguist be debarred from the practice of naming and describing his sensations?

Third, the stage-setting argument has nothing to say against someone already in possession of a public language choosing to ostensively define new sensation words, since such a person obviously has the required stage-setting.


It is #258 which most commentators think of as containing `the' Private Language Argument:

          Let us imagine the following case. I want to keep a diary about the recurrence of a certain sensation. To this end I associate it with the sign «S» and write this sign in a calendar for every day on which I have the sensation. -- I will remark first of all that a definition of the sign cannot be formulated. -- But still I can give myself a kind of ostensive definition. -- How? Can I point to the sensation? Not in the ordinary sense. But I speak, or write the sign down, and at the same time I concentrate my attention on the sensation -- and so, as it were, point to it inwardly. -- But what is this ceremony for? For that is all it seems to be! A definition surely serves to establish the meaning of a sign. -- Well, that is done precisely by the concentrating of my attention; for in this way I impress on myself the connexion between the sign and the sensation. -- But «I impress it on myself» can only mean: this process brings it about that I remember the connexion right in the future. But in the present case I have no criterion of correctness. One would like to say: whatever is going to seem right to me is right. And that only means that here we can't talk about `right'.

A reconstruction of this argument against private language might run as follows:

(1) In any (possible) language, there must be an is right/seems right distinction;

(2) In a private language, no such distinction can be drawn; so

(3) There cannot be a private language.

The idea behind (1) is presumably the unobjectionable one that meaning is normative. To say that a word has meaning is thereby to say that there are (or can be) uses of the word which are correct (right) and uses which are incorrect (wrong). What makes, e.g., `table' a word (part of a language), rather than a meaningless squiggle, is that there are uses of it which are clearly correct, and uses of it which are clearly incorrect. It is just this distinction which Wittgenstein thinks cannot be made out by the private linguist: in trying to give meaning to a sign by `inner' ostensive definition, «... I have no criterion of correctness. ... whatever is going to seem right to me is right. And that only means that here we can't talk about `right'.» (#258) Hence the rationale for (2).

I think there are many problems with this argument, but here is one which I take to be decisive. As noted above, it is generally agreed that contingently private languages (such as a Crusoe language or a private code) are possible. Does the #258 argument not exclude such languages? That is, is premise (2) not indifferent to whether the private language is contingently private or logically private? After all, our socially isolated Crusoe, who invented his own language from scratch, can only rely on his memory and senses, just like the private sensation linguist. How then can Crusoe make out an is right/seems right distinction? It may be replied that Crusoe does indeed speak a language when he names the trees and mountains around him, and that his language admits of an is right/seems right distinction, in virtue of the fact that we could, in principle, learn his language and so make sense of what it would be for some of his uses to be mistaken.

However, a defender of the possibility of a logically private language can reasonably reply that this response begs the question: it simply assumes that an is right/seems right distinction is available only for languages which others can in principle learn. Why should this be conceded? Moreover, if Crusoe speaks a language, he surely does so in virtue of intrinsic facts about him, his world, and his intentions. He does not do so in virtue of the fact that we might understand and correct him. His speaking a language cannot rest solely, or even partly, on such modal considerations.


According to the Cartesian Model, each of us defines the meaning of his sensation words in his own case. I define, e.g., `headache' with reference to my headaches; you define your token of that word with reference to your headaches. Thus sensation words get their meaning in virtue of an act of `inner' ostensive definition. The arguments of #257 and #258, since unsuccessful, have not undermined the Cartesian Model. Of course, this is not to say that there may not be good objections to the Cartesian Model, at least conceived as an historical account of how natural language sensation words get their meaning. Plainly, children do not typically learn words like `headache' or `tickle' in the manner suggested by the Cartesian Model. Learning to make third-person attributions is as much part of coming to learn the meaning of our sensation words as learning to make first-person attributions. Wittgenstein offers other, more sophisticated, objections: for example, how could someone defining `pain' in terms of the Cartesian Model as much as form a conception of another's pain? «I have to imagine pain which I do not feel on the model of pain which I do feel» (#302) which is « ... a none too easy thing to do ... .» (#302) The typical Cartesian reply -- appeal to the Argument from Analogy -- is given short shrift (#293).

Despite the Model's historical inaccuracy, answers to the following questions are still open. First, even if the Cartesian Model, as an historical account, is not the whole truth, might it be part of the truth? Second, might the Cartesian Model be (wholly) valid in some possible scenarios?

That there is a residual truth in the Cartesian Model is supported by the intuition that certain concepts (typically sensation and secondary quality concepts) seem to have an essentially experiential aspect to them. And this implies that, e.g., a colour-blind individual, however competent he may be in the use of the word `red', could not be said to possess (or fully possess) our concept of red. Wittgenstein expresses the temptation to think that a word like `red' has both a public meaning and a private one as follows: « ... the word `red' means something known to everyone; and in addition, for each person, it means something only known to him.» (#273)Foot note 5_5 Such intuitions are not universally shared amongst philosophers, but they are plausible. Given this, there may be some residual truth in the Cartesian Model.

What of the second, modal, question? Having criticised the #257 and #258 arguments, it's hard to see what objection there could be to a competent English speaker choosing to use the Cartesian Model in order to name and describe his sensations, perhaps for entry in a confidential diary. Indeed it's hard to see what objection there could be to a socially-isolated-from-birth Crusoe naming the mountains and trees around him, and then using the Cartesian Model to define his sensation words. If he can single-handedly generate norms in his thought and speech about his physical environment, and so have in place the necessary stage-setting, why can't he do the same with regard to his mental life?


Whatever the verdict on the Cartesian Model, it is important to note a key assumption, made by Wittgenstein and most parties to the debate: that sensation words defined in terms of the Cartesian Model have logically private meanings. That is, it is assumed that the private sensation language of #258 is, or purports to be, a logically private language.

But is this assumption correct? Why think that the diarist of #258, if he speaks a language at all, speaks a logically private language? Two reasons are normally given. First, an epistemic reason: we can never know what meanings the diarist attaches to his words; so we cannot understand his words; so his words have logically private meanings. Second, a metaphysical reason: since sensations are private (i.e., unique and unshareable), and since our diarist defines his sensation words with reference to his own sensations, it follows that his sensation words have logically private meanings.

However, neither reason is compelling. As mentioned above, Craig makes plausible the idea that it is not a constraint on A's understanding B's words that A knows the objects B is referring to. Although Craig does not make this point in the context of criticising the #258 argument, it is relevant here. If the diarist names his own sensations, and I name mine too, there is no good reason to think that we cannot mean the same thing: «[t]here is no particular reason to think that to understand correctly one must know that one understands correctly.»Foot note 5_6 And if it is possible for the diarist and me to mean the same thing, the meanings of his words cannot be logically private.

Second, John Cook goes to great lengths to argue against the idea of sensations as private objects.Foot note 5_7 The standard account of sensations assumes that two people cannot literally have the same sensation, however similar (in duration, intensity, etc.) those sensations might be.Foot note 5_8 According to Wittgenstein, this account misconstrues our language-game with sensations: « ... it is ... possible for us both to have the same pain.»(# 253). On the standard account, the sentence `I have the same headache as my father' (where we both have a headache of exactly similar duration, intensity, etc), understood literally, expresses an impossibility. What we should say is: my father and I have similar, but distinct, headaches. It is this piece of reasoning which, in the name of Wittgenstein, Cook wants to ridicule. He suggests that this reasoning is as wrong-headed as the following: «the sentence `I have the same build as my father' (where we have an exactly similar build), understood literally, expresses an impossibility. Builds are, literally, private. What we should say is: my father and I have similar, but distinct, builds.»Foot note 5_9

According to Cook, the just mooted line of reasoning is a travesty, contrary to the `grammar' of the word `build'. In the case of builds, unlike that of tables and chairs, there is no space for a distinction between `same F' and `exactly similar but distinct Fs'. There is no (strict or literal) sense in which, though exactly alike in build, I fail to have my father's build. In the only sense there is, I have the same build as my father, which I can also express by saying that we have similar builds. It's not as if I have something (my build) which my father cannot have, however physically similar to me he may be. Builds are simply not private in that way.

Cook's suggestion is that the conception of sensations as logically unshareable, gained currency because the language-game with sensations was wrongly assimilated to that for ordinary physical objects (cf #253), with the latter's firm distinction between numerical and qualitative identity. A better model of the language-game for sensations is that for builds (or character, gaits, senses of humour, etc.). Though couched in the terminology of `language-games', this is a conclusion about the nature of sensations, independent of the issue of private language. In which case, our diarist of #258, if he speaks a language at all, would not be speaking a logically private language, since its objects would no longer be thought of as logically unshareable. He would be speaking a contingently private language.


In sum, neither the #257 argument nor the #258 argument undermines the coherence of the Cartesian Model. That model has thus not been refuted, and may indeed be a valid model in certain circumstances. In addition, the key assumption that the diarist's language of #258 is logically private was called into question.

Brian Garrett
Australian National University