WE DON'T KNOW WE HAVE HANDS 107 NICOLIEN JANSSENS WE DON'T KNOW WE HAVE HANDS AND IT'S FINE: BEING OPTIMISTIC ABOUT SKEPTICISM ABSTRACT Based on the brain in a vat thought experiment, skeptics argue that we cannot have certain knowledge. At the same time, we do have the intuition that we know some things with certainty. A way to justify this intuition is given by semantic contextualists who argue that the word "knows" is context sensitive. However, many have objected to the intelligibility of this claim. In response, another approach called "moderate pragmatic contextualism" was invoked, which claims that "knows" itself is not context sensitive, but knowledge assertions are. I show, however, that to refute skepticism, moderate pragmatic contextualism rests on unjustified and implausible assumptions as well. Since no form of contextualism works as a response to skepticism, I argue that we should simply accept skepticism. However, I argue that skepticism is not a problem because skeptic pragmatic contextualism can offer a plausible explanation of why we have the intuition that our ordinary knowledge claims are true, even though they are not. I conclude that skeptic pragmatic contextualism offers the most plausible response to the brain in a vat thought experiment. 108 WE DON'T KNOW WE HAVE HANDS 109 STANCE | VOL. 13 I. INTRODUCTION In the brain in a vat thought experiment ("BIV"), we are asked to imagine that we are brains in vats whose experiences are caused by a supercomputer. Since the experiences of the brains are stipulated to be equal to ours, it seems that we cannot know that we are not brains in vats, as we have no way to tell other than our own experiences. According to skeptics, BIV therefore shows that we can never be sure about the existence of the external world. However, intuitively we have the feeling that we do know certain things about the external world. For example, that we have a body with legs, arms, and a head. In this way, we arrive at a paradox. On the one hand, BIV shows that we cannot have knowledge of the external world, while on the other hand we have the intuition that we do have some knowledge of the external world. So, one of the two claims has to go. Either we cannot have knowledge about the external world and skepticism is right, or there must be some way we can know that we are not brains in vats and skepticism is false. Semantic contextualism is a recent and fiercely debated position that tries to defend the latter option by arguing that "knows" is context sensitive.1 I elaborate on this proposal in section II. Many have objected, however, to the intelligibility of this claim. Stainton and Pynn invoked another approach, called "moderate pragmatic contextualism," which I discuss in section III.2 This approach argues that "knows" itself is not context sensitive, but knowledge assertions are. To refute skepticism, moderate pragmatic contextualism relies on the claim that "knows" is a low demanding epistemic relation. However, I demonstrate that this is another implausible and unjustified assumption. My aim in this essay will be to show that since no form of contextualism works as a response to skepticism, we should consider accepting skepticism. In section IV, I finally propose a third kind of contextualism, namely skeptic pragmatic contextualism. In skeptic pragmatic contextualism, knowledge assertions are again context sensitive, but "knows" refers to a high demanding epistemic relation, making skepticism true. Skeptic pragmatic contextualism can offer a plausible explanation of why we have the intuition that our ordinary knowledge claims are 1 All kinds of contextualism that I discuss in this essay are epistemic, as they make a claim about knowledge. For brevity, however, I refer to it as "contextualism," instead of "epistemic contextualism." 2 Robert Stainton, "Contextualism in Epistemology and the ContextSensitivity of 'Knows'," in Knowledge and Skepticism, ed. Joseph Keim Campbell, Michael O'Rourke, and Harry Silverstein (Cambridge: The MIT Press, 2010), 137-163; Geoff Pynn, "Pragmatic Contextualism," Metaphilosophy 46, no. 1 (2015): 26-51, 10.1111/meta.12120. true, even though they are not. I conclude that skeptic pragmatic contextualism offers the most plausible response to BIV. II. SEMANTIC CONTEXTUALISM AND SKEPTICISM According to skepticism, we cannot have knowledge about the external world. This thesis is supported by the brain in a vat thought experiment (BIV) which asks us to imagine that we are disembodied brains in vats. Our brains are connected to a supercomputer that stimulates our brains in the same way that our actual brains are stimulated when perceiving the external world. As a result, our evidence about the external world is the same even though there is no external world. From this, skeptics conclude that we have no way to tell whether we are brains in vats or not. Based on this thought experiment, skeptics argue that there are many common-sense beliefs that we think we know, but in fact do not know. One is the belief that we have hands. The skeptic shows that this belief is inconsistent with the possibility of being a brain in a vat and thus false: P1 I do not know that I am not a brain in a vat P2 If I do not know that I am not a brain in a vat, then I do not know that I have hands C I do not know that I have hands Both premises seem true, yet the conclusion is not one we are keen to accept. After all, we do seem to intuitively know that we have hands. Therefore, contextualists try to explain how the conclusion, in a sense, can be false, even though we do not always know that we are not brains in a vat.3 According to contextualists, the reason is that the word "knows" is context sensitive. Sentences of the form "S knows that P" are not simply true or false; rather, the truth-conditions of these kinds of sentences depend on the context of utterance. This kind of contextualism is called "semantic contextualism," because it makes a claim about the semantics of the word "knows." Based on the context sensitivity of "knows," semantic contextualists offer a response to BIV. They argue that uttering something such as Premise 1 changes the context in a way where knowledge becomes harder to acquire. However, we normally do not think about skeptical scenarios; for that reason, the standards for knowledge are normally not that high. Thus, semantic contextualists argue that both our ordinary 3 See David Lewis, "Elusive knowledge," Australian Journal of Philosophy 74, no. 4 (1996): 549-567, 10.1080/00048409612347521; or Keith DeRose, The Appearance of Ignorance: Knowledge, Skepticism, and Context, vol. 2 (Oxford: Oxford University Press, 2018) for examples of semantic contextualism. 110 WE DON'T KNOW WE HAVE HANDS 111 STANCE | VOL. 13 knowledge claims and skeptic claims are, in a sense, true. I am right when I say, "I know I have hands," while at the same time the skeptic is right to say that we cannot know that we are not brains in vats. The crux is that the word "knows" picks out different relations in different contexts. Essential to the semantic contextualist response to BIV is the claim that "knows" is context sensitive. However, this is far from obvious. Early semantic contextualists have tried to argue for the context sensitivity of "knows" by drawing an analogy with gradable adjectives such as "flat" and "small."4 When talking about elephants the standard for "small" is rather high, whereas the standard is low when talking about insects. For this reason, the word "small" is said to be context sensitive. Stanley has pointed out that what is characteristic about gradable adjectives is that they permit degree modifiers.5 We can say, for example, that a certain elephant is small, though not very small. The word "knows," however, does not permit degree modifiers.6 We cannot say "I very know that the elephant is small." Moreover, gradable adjectives all have a comparative form, whereas "knows" does not.7 We can say that something is smaller, but we cannot say, "I know more that the elephant is small." Since "knows" does not behave like a gradable adjective, Stanley concludes that we should be very suspicious of the claim that "knows" is context sensitive.8 In response to this objection, later semantic contextualists have tried to justify the context sensitivity of "knows" in other ways. Some have tried to compare it with indexicals, like "today" and "I," others with ternary relational terms, such as "prefers."9 However, the linguistic differences continued. Thus, there seems to be no linguistic category that exactly matches with "knows." Some have argued that "knows" is a context sensitive category on its own.10 This is not impossible, but one needs solid reasons to explain why "knows" would be such an exceptional category and such reasons thus far have not been given. Therefore, given that there is no obvious semantical evidence, semantic contextualism does look rather implausible. 4 Robert Hambourger, "Justified Assertion and the Relativity of Knowledge," Philosophical Studies 51, no. 2 (1987): 241-269, 10.1007/BF00353649 5 Jason Stanley, "On the Linguistic Basis for Contextualism," Philosophical Studies: An International Journal for Philosophy in the Analytic Tradition 119, no. 1/2 (2004): 123, 10.1023/B:PHIL.0000029353.14987.34. 6 Stanley, "Linguistic Basis for Contextualism," 125. 7 Stanley, "Linguistic Basis for Contextualism," 124-125. 8 Stanley, "Linguistic Basis for Contextualism," 130. 9 Stewart Cohen, "How to be a Fallibilist," Philosophical Perspectives 2 (1988): 91-123, 10.2307/2214070; Jonathan Schaffer, "From Contextualism to Contrastivism," Philosophical Studies: An International Journal for Philosophy in the Analytic Tradition 119, no. 1/2 (2004): 73-103, 10.1023/B:PHIL.0000029351.56460.8c. 10 Nikola Kompa, "The Context Sensitivity of Knowledge Ascriptions," Grazer Philosophische Studien 61, no. 1 (2002): 1-18, 10.1163/18756735-90000772. III. MODERATE PRAGMATIC CONTEXTUALISM Pynn and Stainton argue that there is a different kind of contextualism, namely pragmatic contextualism, that can give a similar response to BIV without requiring "knows" to be context sensitive.11 Instead, pragmatic contextualists argue that what is asserted by knowledge claims is context sensitive. There is a distinction between what a sentence semantically expresses and what a speaker tries to assert with a sentence.12 The former is determined by the rules of language- thus by the meaning of the word "knows"-and determines the truth conditions of the sentence. The latter is determined by the intention of the speaker. The point is that some knowledge claims assert something different than they semantically express. This clarifies how the skeptic's claim that we cannot know that we are not brains in vats, and our daily life knowledge claims, like, "I know I have hands," can both be true in a sense. One claim is semantically true and the other is true pragmatically. Now the important question: which one is semantically true? Pynn argues that it is our ordinary knowledge claim, as he holds that "knows" refers to a low demanding epistemic relation that is relatively easy to achieve .13 This kind of contextualism is called "moderate pragmatic contextualism." Thus, when I utter, "I know I have hands," I am saying something semantically true. In contrast, when I utter, "I do not know that I am not a brain in a vat," I am saying something semantically false. If true, moderate pragmatic contextualism would be able to refute skepticism, without relying on the implausible assumption that "knows" is context sensitive. Moderate pragmatic contextualism, however, has problems of its own. First, it seems implausible that I only assert something true, and not semantically express something true by saying, "I do not know that I am not a brain in a vat." When there is a difference between what a sentence semantically expresses and what is asserted by a sentence, we can always respond with "Considered literally, that is false," whereupon the speaker will say, "If you want to be that precise, you are right. I meant to say something different." For example, if I say, "I ate a plate of pasta," someone might respond, "That is false, because you did not eat the plate itself." I would then answer, "True, I mean I ate a portion of pasta as big as a normal plate." Back to the brain in a vat example, would a similar scenario happen 11 Pynn, "Pragmatic Contextualism," 26-51; Stainton, "Contextualism in Eeistemology," 137-163. 12 Pynn, "Pragmatic Contextualism," 29. 13 Pynn, "Pragmatic Contextualism," 34. 112 WE DON'T KNOW WE HAVE HANDS 113 STANCE | VOL. 13 when I utter that I do not know that I am not a brain in a vat? Probably not. If someone responded to me by saying, "Literally, that is false, maybe you mean something else?" I cannot imagine I would answer, "You are right, I meant that if knowledge was a high demanding epistemic relation, then I would not know that I am not a brain in a vat." No, I would answer, "I do not mean something else; I think we literally cannot know that we are not brains in vats." The whole point of BIV is to show that we can never know that the external world exists. So, we cannot assume that knowledge is a low demanding epistemic relation, and then use this as an argument against skepticism. Pynn and Stainton are basically assuming in this way that we can know that we are not brains in vats. But how can we know this? An additional argument would be needed to show that knowledge is a relatively low demanding epistemic relation, so that we can know that we are not brains in vats. As neither Pynn nor Stainton gives one, they are simply begging the question. Finally, moderate pragmatic contextualism implies a rejection of the closure principle. According to the closure principle, if S knows P and S knows that P entails Q, then S knows Q. Schematically: P1 S knows P P2 S knows that P entails Q C S knows Q For example, suppose I know that it is raining. Furthermore, I know that when it is raining, it is cloudy. Then I know it is cloudy. Recall BIV: P1 I do not know that I am not a brain in a vat P2 If I do not know that I am not a brain in a vat, then I do not know that I have hands C I do not know that I have hands We can see that the argument is an instance of the closure principle. After all, the fact that I do not know that I am a not a brain in a vat entails that I do not know that I have hands. However, according to moderate pragmatic contextualism "I know I have hands" is literally true, whereas "I know I am not a brain in a vat" is literally false. As such, they must reject the closure principle, since they argue that it is possible to know that you have hands without knowing that you are not a brain in vat. It is possible to reject the closure principle to refute skepticism.14 However, rejecting closure involves embracing that it would be possible for me to say, "I know I have hands, while I do 14 Robert Nozick, Philosophical Explanations (Cambridge: Harvard University Press, 1981); Fred Dretske, "The Case Against Closure," in Contemprary Debates in Epistemology, 2nd ed. (Chichester: Wiley-Blackwell, 2014), 27-40, for example, have done this. not know I am not a handless brain in a vat." This sounds downright contradictory. It is precisely because contextualists found this move implausible that they came up with another way to refute skepticism.15 The fact that moderate pragmatic contextualism still implies a rejection of the closure principle shows that something has gone profoundly wrong with this proposal. In sum, the aim of moderate pragmatic contextualism was to overcome the linguistic problems of semantic contextualism. I have shown, however, that moderate pragmatic contextualism has its own problems. Firstly, it seems implausible that we can only assert something to be true by saying we do not know that we are not brains in vats. Secondly, moderate pragmatic contextualism is unjustified to assume that knowledge is a low demanding epistemic relation. Finally, it implies a rejection of the closure principle. Hence, moderate pragmatic contextualism is not able to give an appealing response to skepticism. IV. SKEPTIC PRAGMATIC CONTEXTUALISM We have seen that both semantic contextualism and moderate pragmatic contextualism rest on implausible and unjustified assumptions to refute skepticism. Yet, we do need to answer the question, "Do I know that I have hands or not?" As there seems no satisfactory way to reject skepticism, I propose we should accept it. It thus turns out we cannot have knowledge about the external world, thereby admitting that it is literally false that I know that I have hands, and literally true that I do not know that I am not a brain in a vat. Yet, what I will call "skeptic pragmatic contextualism" is still able to explain why we do seem to have knowledge about various ordinary things. Skeptic pragmatic contextualism differs from moderate pragmatic contextualism only in holding that "knows" semantically refers to a high demanding epistemic relation, rather than a low demanding epistemic relation. As a result, in contrast to moderate pragmatic contextualists, skeptic pragmatic contextualists grant skeptics that it is literally true that we do not know that we have hands. Meanwhile, just like moderate pragmatic contextualism, skeptic pragmatic contextualism acknowledges that what is asserted by knowledge claims is context sensitive. Therefore, skeptic pragmatic contextualism explains why, although our ordinary knowledge claims are all literally false, they can all assert something true. In this way, the skeptic pragmatic contextualist can accommodate the intuition that we do have the feeling we know we have hands, as 15 See Keith DeRose, "Solving the Skeptical Problem," 29. Semantic contextualists can preserve closure, provided we hold our context of attribution constant. For moderate pragmatic contextualists this move is not available, as closure fails even within the same (literal) context. 114 WE DON'T KNOW WE HAVE HANDS 115 STANCE | VOL. 13 the semantic meaning is different from what we try to assert by the statement, "I know I have hands." The assertion, "I know I have hands," seems intuitively true because I do not intend to say that I am one hundred percent sure that I have hands, but rather that on the condition I am not a handless brain in a vat, I am sure I have hands. When we have the feeling that we have knowledge about the external world, we are thus confusing the semantic meaning of "knows" with what we mean by uttering knowledge claims. BIV seems paradoxical, because we are mixing up semantic meanings with assertions. In this way, skeptic pragmatic contextualism can explain the seeming paradox raised by BIV, and can also satisfactorily explain many of our ordinary knowledge attributing practices. Consider the following scenario sketched by Cohen: Mary is at the airport considering taking a certain flight to New York. She wants to know whether the flight has a layover in Chicago. She overhears someone ask a passenger Smith if he knows whether the flight stops in Chicago. Smith looks at the flight itinerary he got from the travel agent and responds, "Yes I know - it does stop in Chicago." It turns out that Mary has an important business contact she has to make at the Chicago airport. Mary wonders, "How reliable is that itinerary? It could contain a misprint. They could have changed the schedule at the last minute." Mary concludes that Smith does not really know that the plane will stop in Chicago. She decides to check with the airline agent. 16 In the example, both Smith, who says he knows that the flight stops in Chicago, and Mary, who says she does not know that the flight stops in Chicago, seem to be right. Yet, their assertions contradict each other. Skeptic pragmatic contextualism can explain this by pointing out that Mary and Smith assert something different by saying, "I know the plane stops in Chicago." Smith asserts that according to his flight itinerary, there is a layover in Chicago. Mary, in contrast, wants to know whether there will be a layover in Chicago according to the latest schedule. Therefore, Mary concludes that Smith does not know whether the plane stops in Chicago according to the latest schedule. This shows that skeptic pragmatic contextualism is not just an ad hoc response to skepticism, but that there are good reasons-independent of BIV-to believe in skeptic pragmatic contextualism. One might object that it seems implausible that we are using "knows" in a lenient way all the time. However, if we take a closer look at our ordinary talk, it turns out that we speak loosely not only about knowledge, but about many things. I also say that I do not 16 Stewart Cohen, "Contextualism, Skepticism, and The Structure of Reasons," Philosophical Perspectives 13 (1999): 59, 10.1111/0029-4624.33.s13.3. drink, which is literally false, when I mean to say that I do not drink alcohol. When I say that my phone is empty, this is literally false, as my phone is not hollow from the inside. In this vein, Unger has argued that our knowledge claims are idealizations, just as much of our daily talk consists of idealizations.17 Think of "flatness" and "circularity." Nothing in the world is perfectly flat or circular, yet we often find ourselves saying things like "the Netherlands are flat" or "coins are circular." Thus, it is not strange at all to admit that we make false knowledge claims all the time. Rather, it would be strange if knowledge claims were an exception to the rest of our ordinary idealized talk. As we have seen in the previous paragraph, earlier forms of contextualism are criticized for begging the question against skepticism. Semantic contextualists claim that in daily life "knows" has a different meaning, and moderate pragmatic contextualists claim that skeptics assert something different by knowledge claims than ordinary speakers. However, skeptics claim that we cannot ever have certain knowledge, not even in a daily-life context. As such, earlier forms of contextualism simply bypass the skeptic without further justification. Skeptic pragmatic contextualism, on the other hand, cannot be criticized for this. After all, according to skeptic pragmatic contextualism, skepticism is simply true: we cannot have certain knowledge. However, I have tried to make clear in this paper that this should not bother us in our daily lives. By making a distinction between assertions and semantic meanings, skeptic pragmatic contextualism explains why we still use the word "knows" so much in our everyday life. We speak loosely when making knowledge assertions, thus making literally false, but assertedly true claims. As we have seen, this happens to not only to be the case for knowledge claims, but for most of our ordinary speech. I therefore conclude that skeptic pragmatic contextualism offers the most appealing response to BIV. V. CONCLUSION In this essay, I have shown that there is a straightforward argument available for skeptic pragmatic contextualism showing that it is not strange that our ordinary knowledge claims are literally false. When making a knowledge claim in daily life we speak loosely, just as we speak loosely about countless other things in our daily lives. Therefore, I conclude that skeptic pragmatic contextualism offers the most appealing response to the brain in a vat thought experiment. 17 Peter Unger, Ignorance: A Case for Scepticism (Oxford: Oxford University Press, 1975). 116 117STANCE | VOL. 13 WE DON'T KNOW WE HAVE HANDS While publishing this paper, Nicolien Janssens finished her undergraduate degree in philosophy. Currently, she is doing the Masters of Logic at the University of Amsterdam, where she combines disciplines such as philosophy, logic and cognitive science to get to know more about the limits, dynamics and acquisition of knowledge.