(Added October 2016: my most up-to-date treatment of propositions can be found in Chapter 6 of my PhD thesis. This is an early, undeveloped attempt.)
As I use the term 'proposition', propositions are propositional signs (e.g. declarative sentences) together with their internal uses or meanings, plus any external projective relations borne to reality by the component signs.
This is partly inspired by the conception of propositions espoused in the Tractatus, but also the conception of meaning espoused in Part I of Philosophical Grammar, 'The Proposition and its Sense' and various contemporaneous documents of Wittgenstein's thought– that is, the middle Wittgenstein. Roughly speaking, the 'projective relations' component comes from the Tractarian conception, and the internal meaning component comes from the later conception of meaning.
Before explaining, in my own terms, these conceptions as I have them, I will briefly quote these sources. Here is entry 3.12 of the Tractatus:
I call the sign with which we express a thought a propositional sign.—And a proposition is a propositional sign in its projective relation to the world.
And here is an excerpt from remark 27 of Philosophical Grammar:
As I use the term 'proposition', propositions are propositional signs (e.g. declarative sentences) together with their internal uses or meanings, plus any external projective relations borne to reality by the component signs.
This is partly inspired by the conception of propositions espoused in the Tractatus, but also the conception of meaning espoused in Part I of Philosophical Grammar, 'The Proposition and its Sense' and various contemporaneous documents of Wittgenstein's thought– that is, the middle Wittgenstein. Roughly speaking, the 'projective relations' component comes from the Tractarian conception, and the internal meaning component comes from the later conception of meaning.
Before explaining, in my own terms, these conceptions as I have them, I will briefly quote these sources. Here is entry 3.12 of the Tractatus:
I call the sign with which we express a thought a propositional sign.—And a proposition is a propositional sign in its projective relation to the world.
And here is an excerpt from remark 27 of Philosophical Grammar:
[…]
A name has meaning, a proposition has sense in the calculus to which it belongs. The calculus is as it were autonomous. - Language must speak for itself.
I might say: the only thing that is of interest to me is the content of a proposition and the content of a proposition is something internal to it. A proposition has its content as part of a calculus.
The meaning is the role of the word in the calculus.
The meaning of a name is not the thing we point to when we give an ostensive definition of the name; that is, it is not the bearer of the name.
I do not, however, want to give the impression that I agree with everything in Part I of Philosophical Grammar. Indeed, immediately after the passage quoted above, Wittgenstein asserts that the name 'N' is synonymous with the definite description 'The bearer of “N”'. I think this is a sheer mistake, for Kripkean reasons which were not highly visible when Wittgenstein was writing – these expressions exhibit, for example, different behaviour across counterfactual scenarios. But this doesn't mean I don't agree with Wittgenstein's general way of thinking about (internal) meanings as roles in language-systems – I just don't agree about this case, i.e. don't agree that 'N' and 'The bearer of “N”' play the same role.
And remark 36:
If we look at the actual use of a word, what we see is something constantly fluctuating. In our investigations we set over against this fluctuation something more fixed, just as one paints a stationary picture of the constantly altering face of the landscape.
When we study language we envisage it as a game with fixed rules. We compare it with, and measure it against, a game of that kind.
And from the earlier work in Philosophical Remarks:
3. […] The words 'Colour', 'Sound', 'Number' etc. could appear in the chapter headings of our grammar.
7. Grammar is a 'theory of logical types'.
15. What does it mean, to understand a proposition as a member of a system of propositions? (It's as if I were to say: the use of a word isn't over in an instant, any more than that of a lever.)
I will now briefly explain what I mean by 'projective relations' (or 'external meaning') and 'internal meaning'. As a preliminary, I should say that I make no presumption that I mean what Wittgenstein meant in the Tractatus by 'projective relations'. The ideas are certainly related, but I think not likely to be the same, especially since I have two components side by side here – internal and external meaning – the first of which is inspired by later work of Wittgenstein's. The second component I have been inspired by the Tractatus to gloss as 'projective relations', but since in the Tractatus it was the only component besides the sign, it seems reasonable to suppose that the Tractarian notion may have covered more, so to speak, than mine. Furthermore, this way I adopt of distinguishing between internal and external aspects of meaning – although it owes a lot to Frege's distinction between sense and reference and similar earlier distinctions, and does some of the same work, is not quite there even in the later Wittgenstein, although his work no doubt helped us along the way to it. Rather, it begins in a clearly recognizable form with Putnam's Twin Earth thought experiment and subsequent discussions of semantic externalism.
I will try to explain what I mean by 'projective relations' by explaining how, and why, this notion differs from that of 'referential relations': we can distinguish between my name 'O' for some object in my environment, and a name 'O' used in exactly the same way (internally speaking), but for another object, e.g. by a Twin Earth counterpart of me. For this, the notion of referential relations does the job. But there is an analogous distinction we can make for terms which fail of reference. For example, 'John' when I falsely believe that a man called John came to my friend's house, when my friend has in fact fabricated the whole thing, and 'John' used in the same way on Twin Earth. Both terms fail to hit a mark, so to speak, but their trajectories are in different places. Or: both fail to catch anything in their net, but the nets (which are the same) are cast in different places. So we can say that 'John' and Twin Earth 'John', as well as 'O' and Twin Earth 'O', bear different projective relations to the environment. As for referential relations on the other hand, both 'John' and Twin Earth 'John' bear none, and so cannot be differentiated on that score.
To be clearer about what I mean by '(internal) uses or meanings': by 'internal use' I do not mean to include all the historical facts about how the symbol gets used – rather, I use it similarly to 'internal meaning', namely to mean something like: an expression's role in the language-system it belongs to. Uses or meanings can be individuated in different ways – at different granularities, and factoring in different sorts of features..
So, we may say that propositions are propositional signs together with their internal meanings and their external meanings. And internal meanings can be carved up at different granularities – what you may at one granularity call two instances of the same proposition may at another granularity count as (instances of) different propositions.
As with my account of names, this account of propositions can only be properly understood once the distinction I make between internal and external meaning, and my doctrine of semantic granularity, are properly understood. I will try to explain these things in forthcoming posts.
There seems to me to be an important methodological difference between, on the one side, this conception of propositions which I advocate, and on the other side, certain conceptions prominent in contemporary analytic philosophy. The conceptions I have in mind could be called more technical – we may roughly characterize them by saying that they perform theoretical identifications; they conceive objects, often using formal methods such as basic set theory, and then identify propositions with these. Two basic examples are:
(1) Sets of possible worlds conceptions, on which, for example, the proposition that snow is white is identified with the set of possible worlds in which snow is white.
(2) Russellian conceptions, on which, for example, the proposition that Socrates is mortal is identified with the n-tuple whose first member is Socrates, and whose second member is mortality.
And things get more sophisticated from there – to take three examples: Russellian annotated matrices, two-dimensional semantic values, and objects comprising, among other things, sentences of formal languages.
It is important to realize that there is a methodological difference here, lest it appear that my account is so to speak on the same level, playing the same game, only less precise and less technically developed than, e.g., those mentioned above.
To my way of thinking, those objects which are sometimes identified with propositions are models of, so to speak, real propositions. It may in some cases of other views be indeterminate, or in determinate cases may vary from case to case, whether there is substantive disagreement here or only terminological difference. I am not trying to police other people's use of words, and if they want to call technical constructions like those mentioned above 'propositions', I am not going to object (although I prefer to talk differently). But when these things are said to be – without the words I am about to use being given special technical meanings – objects of belief, or meanings of sentences, or the things we convey in communication, or work with in deductive arguments, I become uneasy at the very least, and in many cases (e.g. set-of-worlds conceptions) disagree confidently. Such ideas seem like category-mistakes to me, or perhaps more true to the case, so impossibly revisionary that they constitute methodologically misguided philosophy (I am thinking of David Lewis here).
My method, then, is to work with semantic concepts more as they are, treating them as more sui generis. I think this is what Wittgenstein did, and what Moore did (I have not gotten a lot out of Moore directly), and I think it is also the way Kripke works in Naming and Necessity and auxilliary works like 'A Puzzle about Belief' (but this is not to deny that much of that work was informed and inspired by Kripke's formal work). I am trying to refine special versions of these notions for philosophical purposes – I am not doing ordinary language philosophy, for example, or concerning myself directly with how “the folk” think about meaning. Rather, I am using my natural lights as one of those folk, together with what I've learned from philosophers, and trying to do philosophy of language in a way which stays close to the phenomena and works with intuitively compelling considerations.
One reason this sort of methodology has fallen out of favour in some circles, I think, is Quinean skepticism about semantic concepts, and hangovers therefrom. Few still go as far as Quine, but the confusing individuation-behaviour he cited as his main reason for abandoning serious use of semantic concepts - the phenomenon I explain in terms of semantic granularity-shifts – seems now to militate, not toward self-conscious abandonment of semantic concepts, but supposed “reconstructions” or cleaned-up versions of them which are so far from the real thing, that they are better thought of as models – models which involve serious idealizations and often great limitations.
So far, I have said in broad outline what propositions are on my account: propositional signs together with their internal meanings (i.e. systematic roles) and their external meanings. I have said a little bit about internal/external meaning, deferring further explanation to other posts. And I have made some methodological remarks about what sort of account this is.
A word on my concept of 'propositional sign': this is no purely syntactic category (whatever that means exactly). Its objects – the things which are propositional signs – are indeed to be regarded as syntactic items, not intrinsically carrying meaning, but the concept which picks them out should probably be thought of as doing so via the broadly semantic notion of a proposition. That is, propositional signs do not count as such in virtue of their intrinsic syntactic features, but because they get used propositionally. This of course means that we haven't got any kind of reductive analysis here of 'proposition', or a 'propositional sign', or 'used propositionally' for that matter, but that was never the intention. (I am sympathetic to Wittgensteinian views on this matter. For example, I think it can be said that 'proposition' is not a sharply bounded concept. Perhaps it can be said to be a family resemblance concept. Perhaps it can be said to function by means of paradigms.)
A word on type-token ambiguity: I have deliberately left my account type-token ambiguous. Just as with sentences, I think we should have a type-token ambiguity which can be resolved when need be, when talking about propositions on my conception. So that we can say (in “token” mode) things like 'Regarding that proposition written on that piece of paper ...' and 'Regarding the proposition that just came out of your mouth ...' without any inaccuracy (e.g. without having to maintain that, strictly speaking, we were talking about instances of propositions, so that to make what we said both explicit and literally correct we should have to add 'instance of a' before 'proposition' in the exampled phrases), but also, for example, 'He uttered the same proposition as I did'.
A word on usage: 'proposition' is often used in such a way that no particular signs – whether tokens or types – are part of the entity in question. For example, when it is said that 'Snow is white' and 'Schnee ist weiss' 'express the same proposition'. I have no special problem with talking like that, and am open to doing it myself in informal contexts or the context of someone else's philosophy, but on my account, and the way I like to use words in conjunction with it, what we are talking about in such cases is not a proposition, but a proposition-meaning. (We may think of proposition-meanings as comprising both internal and external aspects, as propositions minus the sign, so to speak. And of course we may also pick out just one component.)
I will conclude by mentioning some applications to, or connections with, other topics. One application of the account is in solving Frege's Puzzle, in the way indicated in the post on names. Another, where granularity comes into its own, is with Kripke's Puzzle (about belief), which I will discuss in a future post. Among other applications which will be dealt with in future posts are accounts of three major notions in propositional typology: the a priori/empirical distinction, the analytic/synthetic distinction, and the distinction between necessity and contingency in the metaphysical or subjunctive sense.
References
Wittgenstein:
Wittgenstein, Ludwig (1974). Philosophical Grammar. Blackwell.
Wittgenstein, Ludwig (1975). Philosophical Remarks. University of Chicago Press.
Wittgenstein, Ludwig (1922). Tractatus Logico-Philosophicus. Dover Publications.Other:
Saul A. Kripke (1980). Naming and Necessity. Harvard University Press.
Saul A. Kripke (1979). A puzzle about belief. In A. Margalit (ed.), Meaning and Use. Reidel.
