DOI: 10.1111/phin.12232 Philosophical Investigations 42:2 April 2019 ISSN 0190-0536 On Certainty: Wittgenstein and Einstein Giovanni Mion, Istanbul Technical University Abstract The paper focuses on the role of relativistic ideas in Wittgenstein’s philosophy. In particular, it focuses on On Certainty (1969), where in (305), Wittgenstein explicitly invokes Einstein’s theory of relativity: “Here once more there is needed a step like the one taken in relativity theory.” The aim of the paper is to establish a connection between Wittgenstein and Einstein that is both theoretically and exegetically sound. In particular, the paper argues that Wittgenstein’s reaction to scepticism closely resembles Einstein’s reaction to the ether. I. Introduction The connection between Wittgenstein and Einstein has been duly explored. Quite recently, Carlo Penco (2010) and Martin Kusch (2011 and 2015) attempted to link several aspects of Wittgenstein’s philosophy to Einstein’s special theory of relativity. Their methodologies diverge: Penco takes a historical perspective, while Kusch is more interested in theoretical problems. Yet, their conclusions are strikingly similar: both of them argue that Einstein’s influence on Wittgenstein was genuine, and that some of Einstein’s ideas can be profitably used in order to illuminate Wittgenstein’s philosophy. Among other things, Kusch and Penco engage the following issues: verificationism (Penco), holism (Penco), rule-following (Penco and Kusch), scheme-content dualism (Kusch), relativism and scepticism (Kusch). Following their lead, I also wish to focus on the role of relativistic ideas in Wittgenstein’s philosophy. However, in contrast to them, I will only focus on On Certainty [OC], where, in (305), Wittgenstein explicitly invokes the theory of relativity: “Here once more there is needed a step like the one taken in relativity theory.” My goal is to establish a connection between Wittgenstein and Einstein that is both theoretically and exegetically sound. © 2019 John Wiley & Sons Ltd Philosophical Investigations 164 II. Relativity in On Certainty Notoriously, On Certainty was prompted by Moore’s rebuttal of scepticism in his “Proof on an External World”. When the sceptic claims that we do not know about the existence of an external world, Moore replies that he or she must be wrong, for we do know about the existence of external things. According to him, their existence trivially follows from the fact that we have hands: I can prove now, for instance, that two human hands exist. How? By holding up my two hands, and saying, as I make a certain gesture with the right hand, ‘Here is one hand’, and adding, as I make a certain gesture with the left, ‘and here is another’. And if, by doing this, I have proved ipso facto the existence of external things, you will all see that I can also do it now in numbers of other ways: there is no need to multiply examples. (1939: 145–146) However, according to Wittgenstein, Moore’s reply fails, for, among other things, Moore does not to appreciate the role that propositions like ‘Here is one hand’ and ‘There are physical objects’ actually play “in the system of our empirical judgements”: 137. Even if the most trustworthy of men assures me that he knows things are thus and so, this by itself cannot satisfy me that he does know. Only that he believes he knows. That is why Moore’s assurance that he knows. . . does not interest us. The propositions, however, which Moore retails as examples of such known truths are indeed interesting. Not because anyone knows their truth, or believes he knows them, but because they all have a similar role in the system of our empirical judgements. In particular, Moore seems to believe that the sceptic can be refuted by empirical evidence, and that our knowledge about hands provides the required evidence (OC 35). In contrast to Moore, Wittgenstein claims that the sceptic fails to raise any genuine challenge, for we cannot doubt everything at once (OC 115, 450), in the sense that a genuine doubt presupposes some more or less explicit assumptions (OC 342, 509): 341. That is to say, the questions that we raise and our doubts depend on the fact that some propositions are exempt from doubt, are as it were like hinges on which those turn. So, in contrast to Moore, Wittgenstein argues, among other things, that truisms like ‘Here is one hand’ are not genuine empirical propositions, but assumptions or postulates that are tacitly presupposed in all empirical inquiries (OC 136, 308). They belong to our frame of reference (OC 83). © 2019 John Wiley & Sons Ltd Giovanni Mion 165 As I noted above, my goal is not to assess Moore’s reply to scepticism, nor Wittgenstein’s reply to Moore, or his interpretation of Moore’s philosophy, for that matter. My goal is to attempt to shed some light on Wittgenstein’s understanding of propositions such as ‘Here is one hand’ with the help of the special theory of relativity. This might seem bizarre. Yet, as I am about to argue, the following entry in On Certainty points straight to Einstein: 321. Isn’t what I am saying: any empirical proposition can be transformed into a postulate—and then becomes a norm of description.1 But then Wittgenstein continues: But I am suspicious even of this. The sentence is too general. One almost wants to say “any empirical proposition can, theoretically, be transformed. . .” but what does “theoretically” mean here? It sounds all too reminiscent of the Tractatus. (321) presupposes a conceptual distinction between empirical propositions and norms of descriptions. This distinction is reminiscent of the traditional distinction between necessary truths and empirical truths. For example, in Language, Truth and Logic, Ayer writes that [t]he best way to substantiate our assertion that the truths of formal logic and pure mathematics are necessarily true is to examine cases in which they might seem to be confuted. It might easily happen, for example, that when I came to count what I had taken to be five pairs of objects, I found that they amounted only to nine. And if I wished to mislead people I might say that on this occasion twice five was not ten. But in that case I should not be using the complex sign ‘2 9 5 = 10’ in the way in which is it ordinarily used. I should be taking it not as the expression of a purely mathematical proposition, but as the expression of an empirical generalization, to the effect that whenever I counted what appeared to me to be five pairs of objects I discovered that they were ten in number. This generalization may very well be false. But if it proved false in a given case, one would not say that the mathematical proposition ‘2 9 5 = 10’ had been confuted. One would say that I was wrong in supposing that there were five pairs of objects to start with, or that one of the objects had been taken away while I was counting, or that two of them had coalesced, or that I had counted wrongly. One would adopt as an explanation whatever empirical hypothesis fitted in best with the accredited facts. The one explanation which would in no circumstances he adopted is that ten is not always the product of two and five. (1936: 75–76) 1. (321) is dated 12.3.51, and it succeeds almost immediately (305), which is dated 10.3.51. There is no entry in 11.3.51. © 2019 John Wiley & Sons Ltd Philosophical Investigations 166 As Wittgenstein continues: 380. I might go on: “Nothing in the world will convince me of the opposite!” For me this fact is at the bottom of all knowledge. I shall give up other things but not this. According to Wittgenstein, we would never conclude that ten is not always the product of two and five, precisely because in our community ‘2 9 5 = 10’ is treated as a “norm of description”, as opposed to a mere empirical proposition. Yet, in On Certainty, by switching from the concept of necessary truth to the concept of norm of description, Wittgenstein introduces some revolutionary elements: (I) He claims that theoretically, all empirical propositions can function as a norm of description. (II) He maintains that at least some propositions can be profitably reinterpreted as norms of description. (And, conversely, that some norms of description can turn into empirical propositions: OC 96).2 (I) and (II) ought to be clearly distinguished, otherwise we would fail to appreciate that the target of Wittgenstein’s dissatisfaction in (305) is (I). In particular, when Wittgenstein writes that the sentence “any empirical proposition can be transformed into a postulate – and then becomes a norm of description” is too general, he wishes to straightforwardly reject his Tractatus-like oversimplification: “It sounds all too reminiscent of the Tractatus.”3 In the Tractatus (1921), Wittgenstein maintained that all propositions are pictures of reality (4.01), and that all complex propositions are truth-functions of elementary propositions (5, 5.3). Moreover, he also maintained that it must be theoretically possible to analyse any complex proposition into its hidden elementary constituents: names that signify objects which are simple (2.02, 3.201–3.22, 4.22–4.221). Yet, he was unable to deliver any actual analysis. Even worse, he was unable to provide an example of an elementary proposition, name, or simple object. According to Malcolm’s testimony, he believed that these were mere empirical issues: 2. Accordingly, Antony Kenny writes: “There can also, we may note, be change in the other direction—as is shown by the proposition ‘no man has ever been on the moon’ which Wittgenstein notoriously gave as an example of something that stands fast for us. ‘If we are thinking within our system, then it is certain that no one has ever been on the moon. Not merely is nothing of the sort ever seriously reported to us by reasonable people, but our whole system of physics forbids us to believe it’ (OC 208). Nowadays, of course, it is a matter of straightforward empirical inquiry to ascertain how many men have been on the moon.” (2008: 151) 3. In The Blue Book (1958: 18), Wittgenstein argues that the craving for generality is one of the sources of metaphysics. © 2019 John Wiley & Sons Ltd Giovanni Mion 167 One anecdote should be recorded. I asked Wittgenstein whether, when he wrote the Tractatus, he had ever decided upon anything as an example of a ‘simple object’. His reply was that at that time his thought had been that he was a logician; and that it was not his business, as a logician, to try to decide whether this thing or that was a simple thing or a complex thing, that being a purely empirical matter! It was clear that he regarded his former opinion as absurd. (1958: 70) So, by the time he wrote On Certainty, Wittgenstein believed that there was nothing that all propositions had in common (1953: §65) and that in philosophy, nothing was hidden (1953: §91–92, §126–129). Accordingly, he rejected any philosophical practice which assumed that some things must be theoretically possible. On the other hand, even if not all empirical propositions can be readily transformed into norms, some of them definitely enjoy such a status: 167. It is clear that our empirical propositions do not all have the same status, since one can lay down such a proposition and turn it from an empirical proposition into a norm of description. In particular, a genuine solution to the puzzles raised by the sceptic requires us to reinterpret Moorean propositions like ‘Here is one hand’ as norms of descriptions. This is a radical departure from Moore’s perspective: Moore takes his claims to empirically refute the sceptic; while Wittgenstein takes Moore’s truisms to refute the sceptic because they are norms of description that need to be presupposed or postulated in order to meaningfully raise this or that specific doubt. In short, what Moore takes to be an empirical truth is, for Wittgenstein, in reality a postulate. We are now ready to appreciate the role that relativity plays in Wittgenstein’s thinking. In a vacuum, light travels at approximately 300,000 km/s. Its speed is noteworthy, but the startling fact is that the speed of light is the same in every frame of reference, and this seems to conflict with the principle of Newtonian relativity. So, in order to accommodate the speed of light, Lorentz invoked the presence of an immaterial substance: the ether, for which no independent empirical evidence was even possible. In short, for Lorentz, the ether wind caused a contraction along the direction of motion of the apparatus that was used to measure the speed of light, and such a contraction in turn explained why the speed of light appeared to be always constant. Yet, since any ruler that we might use to detect the contraction in question would also be affected, such a contraction cannot otherwise be tested. For Einstein, the contraction invoked by Lorenz was not the mechanical result of an immaterial ether, but the logical consequence of the fact that the speed of light is actually constant. So, in contrast to Lorentz, Einstein © 2019 John Wiley & Sons Ltd Philosophical Investigations 168 rejected the ether, and he explicitly decided to take the fixity of the speed of light as a postulate of his theory (together with Newtonian Relativity). Accordingly, he inferred, among other things, that the spatial distance between two points on a rigid body depended upon the motion of the frame of reference. As Cassirer wrote in his Einstein’s Theory of Relativity: The conflict between the principle of the constancy of the propagation of light and the principle of relativity of mechanics became the “paraclete of thought”—the real awakener of the theory of relativity. But how did physical thought go about overcoming this conflict, since it was bound to the outcome of observation as such, since it could neither set aside the facts expressed in the principle of the constant velocity of light in a vacuum, nor those expressed in the principle of relativity of mechanics? If we look back on the historical development of the theory of relativity, we recognize that the latter has followed here a counsel which was once given by Goethe. “The greatest art in theoretical and practical life,” wrote Goethe to Zelter, “consists in changing the problem into a postulate; that way one succeeds.” In fact, this was the course which Einstein followed in his fundamental essay: Zur Elektrodynamik bewegter Systeme of the year 1905. (1921: 370–371) In short, according to Cassirer, Einstein, implicitly following Goethe’s advice, managed to accommodate the absoluteness of the speed of light within a relativistic framework by changing its status from a mere empirical datum into a postulate of his theory. The connection between Wittgenstein and Einstein should now be clear, and what Cassirer wrote about Einstein’s solution to the conflict between Newtonian relativity and the speed of light might be the link between the two. Be that as it may, the analogies between Einstein’s disagreement with Lorentz and Wittgenstein’s disagreement with Moore are striking, and they alone can justify what Wittgenstein writes in (305): - Neither the ether nor the sceptical hypothesis can be grounded in any empirical evidence: the ether, for Einstein, and the sceptical hypothesis, for Wittgenstein, are the result of an idle theoretical commitment. - Lorentz and Moore take an empirical approach: for Lorentz, the speed of light is a mere empirical datum. For Moore, propositions like ‘There are physical objects’ are straightforwardly empirical. - Both Einstein and Wittgenstein seek a solution to their problems by elevating mere empirical data to the role of a priori postulates. So, for Einstein, the fixity of the speed of light becomes an assumption of his theory of relativity; while, for Wittgenstein, mere empirical propositions such as ‘There are physical objects’ became assumptions that are generally presupposed in all empirical inquiries. © 2019 John Wiley & Sons Ltd Giovanni Mion 169 Finally, the presence of Goethe might also be a significant clue. Goethe’s influence on Wittgenstein is well known,4 and in On Certainty (402), Wittgenstein invokes him as well: “Im Anfang war die Tat” (“In the beginning was the deed”), meaning that our epistemic practices cannot be grounded by rational justification, but only understood in connection with the way we naturally behave (OC 204, 359). Like the speed of light in the special theory of relativity, our epistemic practices “must be taught us as a foundation” (OC 449). III. Conclusion As I wrote in the introduction, the connection between Wittgenstein and Einstein has been duly explored. Yet, the specific connection between OC (305) and OC (321) has gone unnoticed. However, if my reading is correct, by invoking the theory of relativity, Wittgenstein wishes to align his move against Moore with Einstein’s move against Lorentz. In short, by implicitly following Goethe’s methodological advice, both Wittgenstein and Einstein try to find a solution to their problems by changing them into postulates. Department of Humanities and Social Sciences Istanbul Technical University 34469 Maslak – Istanbul Turkey gmion22@gmail.com References Ayer, A. J. (1936/1952). Language, Truth and Logic. New York: Dover. Cassirer, E. (1921/1953). Substance and Function and Einstein’s Theory of Relativity. New York: Dover. Kenny A. (2008). From Empedocles to Wittgenstein. Oxford: Oxford University Press. Kusch M. (2011). “Wittgenstein’s and Einstein’s Clocks.” In E. Ramharter (ed.), Unsocial Sociabilities: Wittgenstein’s Sources. Berlin: Parerga, pp. 203–218. ——— (2015). “A Branch of Human Natural History: Wittgenstein’s Reflection on Metrology.” In O. Schlaudt and L. Huber (eds.), 4. See Monk (1990). © 2019 John Wiley & Sons Ltd 170 Philosophical Investigations Standardization in Measurement. London: Pickering & Chatto, pp. 11–24. Malcolm, N. (1958/2001). Ludwig Wittgenstein. A Memoir. Oxford: Clarendon Press. Monk R. (1990). Ludwig Wittgenstein. The Duty of the Genius. London: Jonathan Cape. Moore, G. E. (1939/2013). Philosophical Papers. Oxon: Routledge. Penco C. (2010). “The Influence of Einstein on Wittgenstein’s Philosophy.” Philosophical Investigations 33(4): 360–379. Wittgenstein L. (1921). Tractatus Logico-Philosophicus. London: Kegan Paul. ——— (1953). Philosophical Investigations. Oxford: Basil Blackwell. ——— (1958). The Blue and the Brown Books. Oxford: Basil Blackwell. ——— (1969). On Certainty. Oxford: Basil Blackwell. © 2019 John Wiley & Sons Ltd