HOW OLD ARE THESE BONES? PUTNAM, WITTGENSTEIN AND VERIFICATION Cora Diamond and Steven Gerrard IÐCora Diamond ABSTRACT Hilary Putnam has argued against philosophical theories which tie the content of truth-claims closely to the available methods of investigation and veri®cation. Such theories, he argues, threaten our idea of human communi- cation, which we take to be possible between people of different cultures and across periods of time during which methods of investigation change dramati- cally. Putnam rejects any reading of Wittgenstein which takes him to make a close tie between meaning and method of veri®cation. What strands in Wittgen- stein's thought appear to lend support to such a reading? Can we do justice to the role which method of veri®cation does have for Wittgenstein while retaining our hold on the idea that communication between people is possible despite substantial differences in methods of veri®cation and investigation? Thus it is as if the proof did not determine the sense of the proposition proved; and yet as if it did determine it. But isn't it like that with any veri®cation of any proposition?1 I n this paper I consider a case invented by Hilary Putnam in the Icourse of his long-running philosophical debate with Richard Rorty.2 Back in the seventeenth century, strange bones have been dug up at Whoozie, and someone wonders how old the bones are. We now know that they are over a million years old; we have used twentieth-century techniques to establish their age. In Newton's time there were no such techniques. But suppose someone to have speculated about the age of the bones. Putnam says that if this person had entertained the idea that the bones 1. Wittgenstein, Remarks on the Foundations of Mathematics (Oxford, 1978), pp. 312±313. 2. H. Putnam, `Newton in His Time and Ours: Will the Real Richard Rorty Please Stand Up?', unpublished. I refer to this article as NTO. 100 IÐCORA DIAMOND were a million years old he would have been right, and if he had rejected it as absurd, he would have been wrong. (Since I refer to this speculator many times, I have given him a name: Leibniz.) Putnam was responding to a suggestion by Rorty that we should rede®ne `true' to `chime with' Heidegger's claim that Newton's laws became true through Newton's work, and that before Newton's discovery they were neither true nor false.3 In developing Heidegger's point, Rorty had said that, if the Latin sentence which Newton used in the seventeenth century to state the principle of inertia had been uttered by someone in the tenth century, it would not then have been a truth-value candidate.It became a candidate for being true or false when there developed a set of coherent and useful practices within which there could be embedded uses of that sentence to make assertions.4 So, if we follow Rorty's recommendation, we should say that the sentence `The bones found at Whoozie are a million years old' became a candidate for being true or false during the twentieth century; and it seems then that we should reject Putnam's claim that, if Leibniz had said that the bones were a million years old, he got something right. Putnam recognizes that there is a reply that Rorty might make. If we say of the sentence `The bones at Whoozie are a million years old', that it did not become true in the twentieth century but was true even back in Leibniz's time, we are merely paying 3. R. Rorty, `Were Newton's Laws True Before Newton?', unpublished manuscript of 8y7y87. For a recent statement of related views, see Rorty, Truth and Progress (Cambridge, 1998), pp. 136±137; for a recent statement of Rorty's view of what is at stake in the debate with Putnam, see `Hilary Putnam and the Relativist Menace', Truth and Progress, pp. 43±62. The disagreement with which I am concerned in the present essay is related closely to Rorty's remark there (p. 60) that he can give no content to the idea of non-local correctness of assertion, without falling back into some form of metaphysical realism. Putnam has denied, throughout the debate, that the idea of non-local correctness makes sense only if we accept metaphysical realism; hence his claim that the seventeenth century speculator was right involves, as he sees it, no going back on his rejection of metaphysical realism. The material in NTO makes explicit the tie between the debate with Rorty and questions about Witt- genstein and veri®cationism. See also Putnam's discussion of Wittgenstein and veri®- cationism, in `The Face of Cognition', the third of his Dewey Lectures, in Journal of Philosophy, 111: 488±517 (1994). 4. Rorty modi®es a ®rst, and relatively simple, statement of his view to allow for translations, but he retains the idea that Newton's sentence, uttered in the tenth century, would not at that point have been a truth-value candidate. HOW OLD ARE THESE BONES? 101 a post-Leibnizian compliment to ourselves. But this, Putnam argues, will not do. He is concerned not just with our twentieth-century talk about the sentence but also with what it means for people to communicate with others, even across periods of time in which techniques of investigation change dramatically. The remark Putnam wants to make about Leib- niz, that he was right about the age of the bones, is then meant to go further than a mere compliment to Leibniz's sentence (understood our way).5 What Leibniz thought, guessed, is what we now know to be so. (One might say that his guess and our knowledge meet.) II How does Wittgenstein come in? Putnam explains his response to Rorty in part by a contrast between Wittgenstein's views and those that were ascribed to Wittgenstein by Norman Malcolm. As Malcolm read him, Wittgenstein closely identi®ed meaning with use in a language-game, and thought of language-games as closed bodies of practices. On that sort of reading, every time a new way of verifying a sentence is invented, the sentence changes in meaning. So Wittgenstein is read as an extreme veri®cationist. From the Malcolmian point of view, the sentence `These bones are at least a million years old' could not have been used in the seventeenth century to make the statement that we make when we use those words today (see NTO, p. 3). There were then no practices of investigation within which the sen- tence was embedded. No seventeenth-century language-game, including those in which the dates of past events were deter- mined and the ages of different objects established, had a route to any sentence like the one about the bones being a million years old. Since, in our use of the sentence, we are playing quite a different language-game from any that existed in the 5. It is meant to be incompatible with the idea that Leibniz's sentence, so far as it is a truth-value candidate, is so only in that we can use it (or a translation of it) to make an assertion. 102 IÐCORA DIAMOND seventeenth century, the sentence now has a different meaning.6 That argument, Putnam says, rests on a tired pseudo-Witt- gensteinian philosophy of language; Wittgenstein himself did not think that a difference in use, in techniques of investigation, implies that there must be a corresponding difference in meaning. Putnam uses the contrast between Wittgenstein's views as he understands them and tired pseudo-Wittgensteinian philosophy of language to formulate his question to Rorty. If Rorty is not trying to return us to something like tired pseudo-Wittgenstein- ianism, if he is willing to allow meaning to be shared by people who do not necessarily share techniques of investigation, then what exactly can be the force of Rorty's recommendation that we treat Newton's laws as becoming candidates for having a truth-value only through the work of Galileo and Newton? The recommendation would be tired pseudo-Wittgensteinianism if it leads us to deny that we might agree with Leibniz about the bones, and leaves us instead merely taking Leibniz's sentence and sticking on to it an honori®c label of `true' or `correct' or `right'. Tired pseudo-Wittgensteinianism would leave us and Leibniz speaking `incommensurable' languages. But if Rorty is not a tired Wittgensteinian, then he will allow that sentences do not change in meaning with every change in technique of investigation. He will allow that we do not just recognize the seventeenth-century sentence as verbally coinciding with a sentence we call true; we understand itÐuttered thenÐjust as we understand it uttered today. Its truth-conditions have not changed; the change is merely that we now know that it was true. How does Rorty stop 6. There is a slight complication in the argument. I earlier spoke of Leibniz as specu- lating. That is, the sentence as he uses it expresses a conjecture or bet rather than a statement that something is so. In giving the Malcolmian view, I follow Putnam in speaking of the statement made in the seventeenth century by a use of the sentence about the age of the bones. If someone using the sentence in the seventeenth century were to be stating, as opposed to guessing, that the bones were a million years old, more conditions would need to be ®lled in. Perhaps the person takes himself to have been told the age of the bones by God in a dream; and so he now asserts `They are a million years old'.