Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi Robert Smithson 1. Introduction Many idealists have worried about the epistemological assumptions of realism.1 The worry is that, if it is possible for truths about ordinary objects to outstrip our experiences in the ways that realists typically suppose, we could never be justified in our beliefs about objects. In response to this argument, philosophers have offered a variety of proposals to defend the epistemology of our object judgments under the assumption of realism. But in this essay, I will offer a new type of epistemic argument against realism to which the standard responses in the literature do not apply. The new epistemic argument can be seen as an inversion of the traditional epistemic argument. The traditional argument (see section 2) considers our actual experiential evidence and argues that it does not, under the assumption of realism, justify judgments about objects. But in the new argument (see section 3), I consider possible situations where we receive evidence that-by the realist's lights-reveals our object judgments to be false. I argue that, even in these possible cases where-according to the realist-we learn that our object judgments are mistaken, we would continue to talk about objects just as we always had. I then argue that the best explanation of this behavior is that, in fact, truths about objects do not outstrip our experiences in the way that realists suppose. In addition to raising a challenge for realism, the epistemology of our object discourse has implications for the idealist's own positive metaphysical view. In section 4, I discuss how the idealist must understand the dependence between objects and our experiences of them if she is to secure epistemic advantages over the realist. 1 See, e.g., Berkeley (1948: 227–30) and Foster (2008: chs. 1–4). 2 A New Epistemic Argument for Idealism 0003203404.INDD 17 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi 18 robert smithson 2. Background I will begin by providing background on the dispute between the realist and the idealist over ordinary objects.2 I will present the new epistemic argument against realism in section 3. 2.1 The Dispute over Idealism For the purposes of this essay, I will characterize the dispute over idealism as a disagreement over the following thesis: Ordinary Object Idealism (OI): Truths about ordinary objects and their manifest3 properties supervene on truths about actual and counterfactual human experiences. Of course, there are other ways of characterizing idealism that may be more useful in other theoretical contexts. In particular, it may sometimes be more useful to characterize idealism in terms of a stronger relation of metaphysical dependence between objects and experiences (see Greco (this volume)) instead of OI's characterization in terms of supervenience.4 But as I explain below, OI is still strong enough to distinguish realists from idealists.5 And given my aims in this essay, it will be most useful to focus on this weaker thesis. While there are many different versions of idealism, proponents have often shared a worry that realism threatens the epistemology of our object judgments. My goal in this essay is to provide a new epistemic argument against realism that is available to many different types of idealists. To this end, OI provides a way of framing the debate that is neutral on many underlying metaphysical issues. For example, each of the following versions of idealism entails OI: • An identity view on which ordinary objects are identified with collections or bundles of sensations (as on one popular interpretation of Berkeley 1948) • A	constitution view on which ordinary objects are constituted by our phenomenal experiences (see Foster 2008) • A	phenomenalist view on which ordinary objects are logically constructed from experiences (see Russell 1985) 2 N.b.: throughout this essay, I will restrict attention to the dispute between realists and idealists as it concerns ordinary objects-items like tables, trees, and human bodies. This dispute may also arise for other types of items, such as the causal relation (see Bernstein (this volume)) or numbers (see Warmke (manuscript)). 3 The scope of OI is restricted to truths about objects' manifest properties: the types of basic properties we seem to be directly acquainted with in experience. Examples of such truths include: 'x is blue', 'x is cubeshaped', 'x and y are twice as far apart as x and z', etc. In contrast, the scope of OI excludes theoretical truths (e.g., 'x is negatively charged') and "higher-level" truths (e.g., 'x is a zebra'). 4 A set of truths A supervenes upon another set B iff there can be no difference in the A-truths without some difference in the B-truths. 5 To be more precise: OI will distinguish realists from idealists so long as there is a certain restriction on the types of experiences considered relevant to the thesis. I will discuss this issue in 2.2. 0003203404.INDD 18 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi A New Epistemic Argument for Idealism 19 In contrast, because she believes that truths about objects depend (at least in part) on truths about some external reality independent of human minds, the realist will deny OI. To see this, consider a Cartesian evil demon scenario: a scenario where our experiences are caused not by a world of material objects, but instead by an evil demon intent on deceiving us. According to the (typical) realist, this is a case where all actual and counterfactual experiences are just as we normally think, but truths about objects are radically different from what we take them to be.6 It is worth noting that OI may not always conform to our intuitive judgments about which views do and do not count as idealist. In addition, I will consider later (see 3.6) whether certain "non-standard" realist views may actually accept OI. But these potential discrepancies are no genuine concern. As I mentioned earlier, there are many ways we might characterize idealism; OI just happens to be the most useful thesis to consider when presenting the new epistemic argument. Suffice to say that this argument will only support versions of idealism that entail OI. 2.2 Counterfactual Experiences Any viable form of idealism must allow for the existence of objects that are not actually experienced by human subjects. Since one prominent strategy for accounting for such objects is to appeal to counterfactual experiences,7 I have appealed to counterfactual experiences when formulating OI. "Counterfactual experiences" should be understood broadly to include all ordinary experiences subjects consider relevant to assessing the truth of judgments about objects. For example, in the case of S* ≡ "There is a cup on the table", the counterfactual experiences might include: the experiences we would have if we were to look towards the table, the experiences we would have if we were to attempt to lift up the apparent cup, the experience we would have if we were to look into a mirror reflecting the table, the experience we would have if we were to use a drone to photograph the table, and so on.8 The appeal to counterfactual experiences raises several questions: • If	the	idealist	rejects	the	existence	of	mind-independent	material	objects,	then what supports the counterfactual experiences mentioned in OI? 6 Of course, certain types of realists deny the coherence of this demon scenario. Will these realists also reject OI? The answer is "yes", but for simplicity, I will postpone discussing such realists until 3.6. For now, I will continue to appeal to the demon scenario to intuitively illustrate the disagreement over OI. 7 See, e.g., Berkeley (1948: 250–6), Dummett (2004: ch. 4), and Mill (2009: ch. 11). 8 On the other hand, it's worth emphasizing the restriction to "ordinary" experiences: the types of experiences of objects we are accustomed to having in everyday life. To see the need for this restriction, suppose it turns out that a demon is causing our experiences. The restriction to ordinary experiences would rule out, e.g.: the experience I would have if the demon revealed its presence to me. If OI allowed for this kind of non-standard experience, then realists might also accept OI. This restriction will also rule out certain trivializing mechanisms, such as: the experience I would have if there was a God who told me the truth about P. Again: if we allowed for such experiences, then realists might accept OI as well. 0003203404.INDD 19 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi 20 robert smithson • How	will	the	idealist	account	for	truths	about	objects	in	environments	where human experiences are not nomically possible (e.g., truths about the insides of stars)? • Can	the	idealist	appeal	to	counterfactual	experiences	without	falling	into	circularity or regress?9 These are important questions, but it is outside the scope of this essay to address them. For now, I will simply assume as a working hypothesis that the idealist has satisfactory responses to these objections.10 2.3 The Traditional Epistemic Argument Many idealists have worried about the epistemological assumptions of realism.11 Suppose that truths about objects outstrip truths about our experiences in the way that realists suppose. Then there could be a world just like ours with respect to all actual and counterfactual experiences but with different truths about objects (for example: a demon scenario). According to traditional idealists, such a possibility would show that our experiences do not justify our judgments about objects. But it is obvious that our experiences do	justify	many	such	judgments.	So	realism	is	false.	Here	is	the	traditional argument as it specifically applies to the thesis OI: Traditional Epistemic Argument Let S be a sentence about objects and their manifest properties that we judge to be true on the basis of our experiences. Premise 1: If truths about objects do not supervene on truths about actual and counterfactual experiences, then our experiences cannot epistemically justify our judgment that S. Premise 2: Our experiences can epistemically justify our judgment that S. ----- Therefore: truths about objects supervene on truths about actual and counterfactual experiences. Despite its historical prominence, few contemporary philosophers accept the above argument. Most realists will reject premise 1 by claiming that, even if it is coherent to suppose that there could be a world with the same actual and counterfactual experiences but with different truths about objects, such possibilities do not threaten the justification of our object judgments. There are different ways one might resist this premise. For example, Vogel (1990) claims that we can justify the existence of material objects using inference to the best 9 See Sellars (1963) for a version of this objection applying to early twentieth-century versions of phenomenalism. 10 In particular, I will ignore potential counterexamples to OI involving environments where human experiences are not nomically possible. 11 See, e.g., Berkeley (1948: 227–30) and Foster (2008: chs. 1–4). 0003203404.INDD 20 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi A New Epistemic Argument for Idealism 21 explanation. Another strategy (see DeRose (1999)) is to give a contextualist defense of our knowledge of material objects, claiming that skeptical hypotheses do not threaten our judgments about objects in ordinary contexts. A third response (see Pryor (2000)) is dogmatism: the view that our object judgments enjoy a default justification that is not threatened by skeptical hypotheses. I think that each of the above proposals provides the realist with a plausible response to the traditional argument. But in this essay, I will raise a new epistemic argument against realism which is not threatened by the standard responses in the literature. 2.4 A New Epistemic Argument The realist views our object judgments as "hostage to fortune" in the following sense: it is coherent to suppose that all actual and counterfactual experiences are just as they are, but due to facts about some external reality independent of human minds, object truths are different. An evil demon scenario might be an example of such a case. But there is a problem: when we consider our actual linguistic behavior, it does not seem that object judgments are hostage to fortune in the way that realists suppose. This can be seen with a simple thought experiment.12 Suppose we travel to the all-knowing, perfectly trustworthy Oracle to settle once and for all whether there is an external world of material objects. There, we receive a disheartening report: our experiences are caused not by material objects, but rather by a malicious demon intent on deceiving us. This testimony would surprise and dismay us. We might say things like "Apples and books don't really exist!" and "We don't have bodies after all!" But this immediate shock would pass. And after several minutes, we would go back to saying things like "There is an apple in the kitchen" or "I'm walking to the bus stop" just as we always had. This is because we would have to return to the ordinary concerns of human life: buying groceries, taking the bus to work, and so on. This thought experiment raises a puzzle. Ordinarily, when we receive evidence E that contravenes our judgment that P, we abandon our judgment that P. But in the above thought experiment, we continue to make judgments about objects even after receiving evidence that-by the realist's lights13-falsifies those judgments. There are various ways we might try to explain this puzzling behavior. But in the next section, I argue that the best explanation of the thought experiment is that realism is false: truths about objects are not hostage to fortune in the way that realists suppose. Here	is	the	argument	step	by	step: New Epistemic Argument Premise 1: Even if we were to receive evidence E about some (alleged) external reality that-by the realist's lights-falsifies our object judgments, we would continue to make judgments about objects on the basis of our experiences. 12 See Smithson (manuscript a: 4.1) for a different version of this thought experiment. 13 As I mentioned in fn. 5, there are some realists who reject the coherence of the demon scenario. For ease of presentation, I will postpone discussing these realists until 3.6. 0003203404.INDD 21 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi 22 robert smithson Premise 2: If we would continue to make judgments about objects even after receiving E, then truths about objects supervene on truths about actual and counterfactual experiences. ----- Therefore: truths about objects supervene on truths about actual and counterfactual experiences. The new epistemic argument can be seen as an inversion of the traditional argument presented in 2.3. The traditional argument considers our actual experiential evidence and argues that it does not, under the assumption of realism, justify judgments about objects. But in the new argument, I consider possible situations where we receive evidence that-by the realist's lights-reveals our object judgments to be false. I argue that, even in these possible cases where-according to the realist-we learn that our object judgments are mistaken, we would continue to talk about objects just as we always had. I then argue that the best explanation of this behavior is that, in fact, truths about objects do not outstrip our experiences in the way that realists suppose. I have already made the case for premise 1 with the Oracle thought experiment. I will defend premise 2 in section 3. 3. Defending Premise 2 As I mentioned above, I think the proper response to the Oracle thought experiment is to abandon the epistemological assumptions of realism. But to establish premise 2, we must rule out ways of responding to the thought experiment that are compatible with realism. I will consider two such proposals in this section. 3.1 Fictionalism In the thought experiment, we continue making judgments about objects even after learning that our experiences are not caused by material objects. 14 One explanation of this behavior is fictionalism. As I will use the term, fictionalism encompasses views on which our object judgments do not aim at the literal truth, but instead involve fiction, pretense, or non-literal speech.15 As a response to the Oracle thought experiment, fictionalism is compatible with realism: even though our object judgments are literally false in the demon scenario, we continue making object judgments because we are pretending or using non-literal speech. While fictionalism provides an attractive response to the Oracle puzzle, it faces a number of independent objections. One issue is that the standard types of evidence indicative of fictional or non-literal speech are absent from our object discourse. For example,	if	a	speaker	says	"I	have	butterflies	in	my	stomach",	and	a	child	asks	"How	do 14 The discussion of 3.1 parallels the discussion of Smithson (manuscript a: 4.2). 15 I address an alternative form of fictionalism-revolutionary fictionalism-in fn. 17. 0003203404.INDD 22 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi A New Epistemic Argument for Idealism 23 you know they aren't moths?", the original speaker will explain that she was not speaking literally.16 The same goes for all other clear cases of non-literal or fictional discourse. But in any ordinary context, speakers have no inclination to retract their object judgments in response to questions like "Is there really a chair?" In addition, the present proposal conflicts with our self-understanding of the distinction between fictional and non-fictional discourse. As the terms 'fictional' and 'non-fictional' are used by ordinary speakers, they mark a clear distinction between judgments like "Romeo loved Juliet" and judgments like "There is a bicycle" (when, e.g., one is pointing to a bicycle). So any theory on which all of our object discourse is fictional fails to respect this distinction as it is actually used.17	Says	Hirsch	(2005:	90): distinctions themselves must be based on a charitable interpretation of what people say. . . . If you simply set yourself the task of interpreting in the most charitable way possible the language of our community, you cannot avoid the conclusion that the ontological sentences typically accepted by the community are true in that language, in the strictest and most literal sense. While fictionalism deserves further discussion,18 the above shortcomings should motivate us to look for a better response. 3.2 Conceptual Change Suppose that, in our sleep, we are magically transported to Twin-Earth.19 Upon waking, and still unaware of our journey, we might turn on a faucet and say "This water is cold". Suppose that the Oracle then tells us about our journey, and tells us that the watery	substance	from	the	faucet	is	XYZ,	not	H2O. We would react by saying things like: "So this liquid isn't really water after all!"20 But if we were to remain on Twin-Earth for a long time, we would probably return to using the term 'water' much like we did before. After all, we would need to communicate with Twin-Earthlings whenever a faucet leaked, and so on. The Twin-Earth case is very similar to the original Oracle thought experiment. In both cases, subjects initially retract their judgment in response to the Oracle's testimony but later return to speaking as they did before. In the Twin-Earth example, it is 16 See Burgess and Rosen (2005: 532–4) for more detailed discussion of this example. 17 Similar remarks apply to views on which object judgments involve pretense or non-literal speech. 18 To resist the above arguments, the realist might claim that, while subjects do not actually use object judgments non-literally, they would decide to do so after receiving the Oracle's testimony. In response: while we can certainly imagine subjects behaving this way, we can also imagine subjects who would simply revert to object judgments without making any such decision. For this reason, I do not think that a "fictionalist revolution" provides a general solution to the puzzle. I raise an additional problem with this response in fn. 25. 19 See Putnam (1975) for the original Twin-Earth thought experiment. In this thought experiment, Twin-Earth is a planet indistinguishable from Earth at the macroscopic level; for example, there is a TwinEarth duplicate of every person and thing on Earth. The only difference is that, whereas the clear, tasteless liquid	in	the	oceans,	lakes,	etc.	on	Earth	has	the	chemical	structure	H2O, on Twin-Earth this liquid has some other chemical structure (abbreviated 'XYZ'). 20 This will be the response of anyone who shares Putnam's intuition that the watery substance on TwinEarth is not water. 0003203404.INDD 23 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi 24 robert smithson natural to diagnose this as a case of conceptual change: our term 'water' first referred to H2O, but later referred to XYZ. It is worth considering whether this response might also apply to the original puzzle. If the meanings of our terms have changed, we can uphold the realist's assumption that our original judgments about objects are false in the demon scenario.21 Against this proposal, there does not seem to be any evidence for conceptual change in the original thought experiment. There are three major factors thought relevant to reference determination: the speaker's environment, the speaker's referential intentions, and usage. Environment explains why the term 'water' shifts reference after spending time on Twin-Earth. But in the original puzzle, we remain in the same environment. As for intentions: we can certainly imagine subjects that, after the Oracle's testimony, stipulate that they will hence forth use object terms with a different meaning. But we can also imagine subjects who simply return to speaking of objects as they did before. So a change in referential intentions does not provide a general solution to the puzzle.22 As for usage: we are assuming that hearing the Oracle's testimony does not affect subjects' use of object terms in ordinary contexts. So none of the characteristic evidence for conceptual change is present in the Oracle case. Summary: On the proposals considered in 3.1 and 3.2, our original judgments about objects are literally false in the demon scenario. In this sense, the above explanations are each compatible with the epistemic assumptions of realism (see 2.4). But unfortunately, these proposals seem to suffer independent shortcomings. Perhaps there is some other way for the realist to explain the continued assertibility of object judgments.23 But in section 3.3, I will argue that we should take our linguistic behavior in the Oracle thought experiment at face value: in the demon scenario, our object judgments are literally true. 3.3 Idealism I think that what the Oracle puzzle really shows is that the realist is simply mistaken about the epistemology of our object discourse. The realist supposes that the truth of our object judgments hinges on facts about some external reality independent of human minds. But there is no evidence that our object judgments are actually hostage to fortune in this way.24 21 On this proposal, the realist would have to provide some story about what our object terms refer to after the Oracle's testimony (e.g., ideas in the demon's mind). 22 The realist might claim that, nonetheless, our implicit referential intentions change after the Oracle's testimony (thanks to Kenneth Pearce for this suggestion). For ease of presentation, I will set this proposal aside until section 4 (see fn. 25). 23 One further proposal worth considering is functional identification: identifying ordinary objects with whatever items in the mind-independent "external world" cause our experiences of objects. I address a version of this proposal in 3.6. I discuss some additional responses in Smithson (manuscript a: section 4). 24 What about the fact that subjects retract their object judgments in the immediate aftermath of the Oracle's testimony? I consider this issue below. 0003203404.INDD 24 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi A New Epistemic Argument for Idealism 25 The real lesson from the Oracle thought experiment is that, in any ordinary context, we do not care about whatever external reality gives rise to our experiences; this is why we continue to make judgments about objects even after receiving the Oracle's testimony. But if this is right, why would we ever think that the truth of these judgments hinges on facts about the nature of some external reality? Such facts could only threaten our object judgments if we cared about this external world. But we don't: in ordinary contexts, we make object judgments in complete indifference to such a world.25 What we do care about is the world as it appears to us: the world presented by our ordinary experiences. So, as long as our actual and counterfactual experiences coherently indicate that there are tables and chairs, we will continue to judge that tables and chairs exist. And there is no reason to regard such judgments as anything less than true in their most literal sense. A question remains: if OI is true, what explains our initial inclination to retract our judgments upon hearing the Oracle's testimony? I think this initial reaction is explained by the fact that we-or those of us initially sympathetic to realism-have false theoretical beliefs about our object judgments. We initially retract these judgments because we assume that they purport to describe some external reality fully independent of human minds. But we soon return to our object talk because this assumption is mistaken. When doing philosophy, we often treat our ordinary judgments as if they are theoretical hypotheses: hypotheses that aim at a certain objectivity or a certain explanatory power. So when we consider a case (such as the demon scenario) where our discourse apparently fails to meet these standards, we are tempted to conclude that our ordinary judgments are defective. But when the concerns of everyday life impinge upon us, we return to speaking as we did before. This is because the use of our language is driven by our interests and concerns, and what matters to us in everyday life is the world as it appears to us.26 25 Of course, we can imagine a community that responds to evidence differently than we do. We can suppose that, when members of this community hear the Oracle's testimony, they give up their object discourse and never return to it again. But this community is not our community. 26 I'll now consider the realist response mentioned in fn. 21: that our implicit referential intentions would change after the Oracle's testimony. I've argued in this section that, in ordinary life, subjects go on in complete indifference to questions about the existence or nature of any external reality independent of human minds. For this reason, I think that all the linguistic dispositions that actually matter to the ordinary use of our object terms would remain the same after the Oracle's testimony. This indifference also raises a problem for revolutionary fictionalism (see fn. 17). Even speakers who actively decided to begin treating object discourse as fictional would soon revert to using the fictional/ non-fictional distinction as they did before. This is because a distinction on which all object discourse counts as fictional would be of no use to us. And we would hardly give up this useful distinction because of concerns about some external reality we are completely indifferent to in ordinary contexts. This suggests that any decision to treat our object judgments as fictional would be semantically idle; it would have no bearing on our actual linguistic behavior and would not provide a real explanation of our response to the Oracle. 0003203404.INDD 25 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi 26 robert smithson 3.4 Summary I have argued that the best explanation of the Oracle puzzle is to reject the epistemic assumptions of realism. This supports premise 2: Premise 2: If we would continue to make judgments about objects despite receiving evidence about some (alleged) external reality that-by the realist's lights-falsifies our object judgments, then truths about objects supervene on truths about actual and counterfactual experiences. Together with premise 1, this supports OI: Ordinary Object Idealism (OI): Truths about ordinary objects and their manifest properties supervene on truths about actual and counterfactual human experiences. 3.5 Objection 1: An Illegitimate Focus on Language I've argued that the realist's mistaken epistemological assumptions are the result of her mistaken metaphysical assumption that truths about objects fail to supervene on truths about actual and counterfactual experiences. It is common for philosophers to use results from epistemology to derive metaphysical conclusions. But some theorists will be unhappy with this style of argument. There are different forms this objection might take. For example, it is sometimes emphasized that metaphysical theories are not about our concepts or the epistemic connections between them; instead, they are about what is out in the world.27 But if this claim is taken to imply that we can ignore the epistemology of our object judgments when theorizing about objects, it is too simplistic. This is because the epistemology of object judgments places constraints on what can count as an object. If a theory T of objects is incompatible with the epistemology of our object discourse, T is simply failing to talk about objects: the things like tables and chairs that interest us in ordinary life. A more interesting objection is to claim that our metaphysical theories need not consider the actual epistemology of our object judgments; instead, they need to consider how subjects should use object terms. For example, one might think that subjects' failure to modify their object discourse in response to the Oracle's testimony merely betrays a failure of imagination, a failure of nerve, or perhaps even a psychological disability.28 One might insist that the proper response to the Oracle's testimony would be for subjects to permanently give up their object discourse. While this objection is interesting, I doubt that there is any viable way to understand the normative force of the 'should' in this objection. The main lesson of the Oracle case is that we do not care about some external reality giving rise to our experiences (see 3.4). But then, given these interests and concerns, it is difficult to see why we should use our object terms different than we actually do. 27 For related discussion, see Dowe (2000: 3). 28 Thanks to Marc Lange for this suggestion. 0003203404.INDD 26 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi A New Epistemic Argument for Idealism 27 3.6 Objection 2: "Non-Standard" Realists When defending premise 2 of the Oracle thought experiment, I used the demon scenario as a case where-according to the realist-all actual and counterfactual experiences are the same, but truths about objects differ. But not all realists adopt this stance. For example, some realists have argued that our object judgments are actually true in a demon scenario because, in such a case, our object terms would refer to (say) ideas in the demon's mind.29 This conclusion can be motivated by a causal or use-based theory of reference. Given this possible stance, there is a worry that the new epistemic argument does not succeed in undermining all versions of realism. To address this worry, we can replace the demon scenario with a new case that should be troubling even to nonstandard realists.30 We can begin by imagining a classical, atomistic Newtonian world-call it WN-populated by n fundamental particles. Roughly speaking, when these particles densely populate certain regions, an appropriately located subject has an experience of an object occupying that region. WN is not itself troubling to the realist. But I will use WN as a model to construct a more difficult case, which I will call W*. In W*, only a small set of particles are relevant to generating all of our conscious experiences. One of these particles-the "mass particle"-has n fundamental properties whose magnitudes at a given time mirror the masses of the particles in WN (at the corresponding time in WN). Similarly, W* contains a "position particle" whose properties mirror the positions of WN's particles. Going on in the same way, a small set of particles in W* "encodes" the entire physical state of WN. In addition, we can suppose that the psychophysical laws in W* act on these particles in such a way as to support the same actual and counterfactual experiences as in WN. The upshot is that, in W*, all of our normal experiences of objects are caused by a very small set of particles. What makes this case especially troubling for the realist is that, unlike in the demon scenario, there do not seem to be any concrete items in W* for our object terms to refer to. For this reason, even non-standard realists will say that our object judgments are false in this case.31 So, by replacing the demon scenario with W* in the defense of premise 2, the new epistemic argument undermines non-standard realisms as well.32 29 For related discussion, see Putnam (1981: ch. 1) and Chalmers (2012: E15). 30 See Smithson (manuscript a: section 3) for other examples. 31 I consider some ways a non-standard realist might resist this argument in Smithson (manuscript a, 4.4–4.5). 32 Incidentally, W* also shows why OI excludes even "non-standard" realists-see fn. 5. Are there any other non-idealist views that might accept OI? One possibility is Dummett's (2004) antirealism. Because Dummett denies that truths about objects are recognition-transcendent, he would likely accept the supervenience of object truths on truths about actual and counterfactual experiences. But on the other hand, Dummett (1978: 19) explicitly contrasts anti-realism with idealism, claiming that anti-realism shows how "we can abandon realism without falling into subjective idealism." This is no serious concern. As discussed in section 2, there is no single best way to characterize idealism. So I am happy to simply grant that Dummett's anti-realism counts as a form of idealism as I use the term in this essay. Similar remarks apply to other borderline cases: any theorist willing to accept the supervenience in OI is idealist enough to count as such on the usage of this essay. 0003203404.INDD 27 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi 28 robert smithson 4. Idealism and Ordinary Epistemology Throughout this essay, I have remained neutral on how the idealist should develop her positive metaphysical view; this is because I wanted the new epistemic argument to be available to different types of idealists. Nonetheless, the epistemology of our object judgments has implications for the idealist's positive metaphysics. In this section, I will discuss how the idealist should understand the dependence between objects and experiences if she is to secure an epistemic advantage over the realist. 4.1 The Deference Principle The epistemic problems for realism arise because the realist assumes that object truths fail to supervene on truths about our experiences. By denying this assumption, the idealist hopes to avoid these problems. But to actually secure this epistemic advantage, there are constraints on how the idealist can view the relation between objects and experiences. In particular, the idealist must endorse the following principle: Deference Principle: Let Si be a sentence concerning ordinary objects and their manifest properties. Let si be the set of (contextualized) counterfactual experiences ordinary subjects would (ideally) consider relevant to assessing the truth of Si. Then an experience e contributes to determining the truth of Si just in case e is a member of si. In particular, Si is true just in case ordinary subjects would (ideally) judge that Si is true when presented with all of the experiences in si. Before clarifying the above terminology, it will be useful to provide an intuitive grip on the Deference Principle by considering some examples: Case 1: S1 ≡ The opposite side of the book is blue. 33 Which experiences do ordinary subjects consider relevant to assessing the truth of S1? One set are the visual experiences I would have if I were to rotate or flip the book around. Another set are the experiences I would have if I were to walk around to the other side of the book, looking at it from the opposite direction. Another set are the experiences other subjects would have when looking at the book from the opposite direction. Another set are the experiences I would have if I were looking into a mirror placed behind the book. All of these experiences will be members of s1. And this merely scratches the surface: any competent subject can imagine (and recognize) countless other examples. The Deference Principle describes how all of the experiences just mentioned determine the truth of S1. In particular, the Deference Principle stipulates that S1 is true 33 With the Deference Principle's restriction to sentences concerning manifest properties, the term 'book' in S1 should technically be replaced by a more neutral expression (e.g., 'book-shaped object'). See fn. 4 for discussion. This being said, I will continue to use terms like 'book' as abbreviations in the discussion ahead. 0003203404.INDD 28 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi A New Epistemic Argument for Idealism 29 just in case ordinary subjects presented with the set of the above experiences would judge that S1 is true. 34	Here	is	a	second	example: Case 2: S2 ≡ The bicycle is green. (Assumption: it is night and nothing is visible) Since it is too dark to see, s2 will not include ordinary visual experiences of the bicycle. But s2 will include: the experience we would have if we were to shine a flashlight on the bicycle, the experience we would have if the sun were overhead, the experiences we would have if we scraped some paint off the bicycle and brought it to a well-lit area, and so on. According to the Deference Principle, S2 is true just in case ordinary subjects presented with the set of these experiences would judge that S2	is	true.	Here	is	a final example: Case 3: S3 ≡ The stick is straight. (Assumption: the stick is partially submerged in water) It is useful to think of this as a case where the experiences in si do not form a mutually coherent set. s3 will include many experiences that indicate that S3 is true: the tactile experiences of the stick, the experiences of the stick when it is taken out of water, and so on. But s3 will also include many experiences that indicate that S3 is false, such as the visual experiences of the stick when it is halfway submerged in water. So what is the truth value of S3, given that s3 is not a mutually coherent set? The answer is built into the Deference Principle: S3 is true just in case ordinary subjects would judge that S3 is true when presented with all of these experiences. In this case, subjects would certainly judge that the stick is straight. After all, we make this judgment on the basis of similar evidence in ordinary contexts all the time. So the idealist will say that S3 is true and that sticks partially submerged in water remain straight.35 While it is outside the scope of this essay to present any further cases, the above examples should help provide a working grip on the Deference Principle. There are two key features of this principle worth emphasizing. 34 There are a few types of experiences that, for simplicity, I will not mention in this or subsequent examples. These include: experiences of memories, experiences involving testimony (either from people, or encyclopedias, or other sources), and experiences that are only relevant to si insofar as they support inductive generalizations that subsume Si. There is no need to mention these experiences since their relevance to Si is plausibly "screened off " by the inclusion of other experiences in si. For example, there is no need to mention experiences of memories given that the experiences on which those memories are based are also in si. 35 With this example, I've gestured at how the idealist should distinguish illusions from non-illusions. Ordinary subjects are able to draw this distinction on the basis of the normal types of experiential evidence available to them. Even if they are unable to make a judgment about veridicality on the basis of their actual evidence, subjects recognize how further possible evidence would bear on such judgments. But if ordinary subjects can distinguish illusions from non-illusions, so can the idealist. This is because ordinary epistemology is directly built into the Deference Principle: whatever criteria ordinary subjects use to identify illusions, the idealist uses the same criteria. 0003203404.INDD 29 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi 30 robert smithson First: with the Deference Principle, truths about objects are determined by the counterfactual experiences included in si (as well as, perhaps, facts about our epistemic practices). In contrast, the principle never invokes truths about an external reality independent of human minds. In this sense, the Deference Principle is incompatible with realism.36 Second: with the Deference Principle, the idealist does not offer an analysis of which specific types of experiences are included in si. For example, I did not try to give an exhaustive list of the types of experiences relevant to determining the truth of S1. Instead the strategy is to defer to ordinary epistemology. This feature ensures that the Deference Principle will not conflict with our intuitions about cases, and will therefore not be subject to counterexamples. Because ordinary epistemology is built right into the Deference Principle, an idealist endorsing this principle is guaranteed to respect the epistemology of our object discourse. 4.2 Clarificatory Notes In this subsection, I'll provide several clarificatory notes on the Deference Principle. (i) Contextualized experiences: The experiences relevant to the principle must be contextualized-that is, presented to a subject with a description of what types of experiences they are. Each experience in si should be paired with a description that includes (at minimum): (a) the subject in question and (b) a description of the counterfactual situation relevant to the experience. Without this information, a subject would be unable to interpret how the experiences in si bear on the truth of Si. 37 (iii) The Cosmoscope: There are various ways to explicate the idea of a subject being "presented with the experiences in si". One option is to invoke Chalmers's (2012) notion of a "Cosmoscope." The Cosmoscope is a hypothetical virtual reality device that allows a user to select a certain counterfactual experience and which then induces that experience in the user.38 For example, a user might select: the experience I would have if I were in position p at time t and were to look toward the book. After appropriate warning, the Cosmoscope would induce this experience in the user. We can think of the subjects in the Deference Principle as using a Cosmoscope to learn about all of the counterfactual experiences in si. (iv) Idealizations: The Deference Principle appeals to the experiences ordinary subjects "ideally" consider evidentially relevant to a given assertion Si. To see why this idealization is needed, consider S2 ≡ "The bicycle is green". s2 cannot be viewed as the 36 Related to this point, the experiences invoked by the Deference Principle should be viewed as the types of "ordinary" experiences of objects we are accustomed to having in everyday life-see fn. 7. 37 When describing the experiences in s1–s3, I directly referred to ordinary objects (e.g., the book, the bicycle). This may seem puzzling, since the experiences in si are themselves supposed to determine truths about objects. This worry is closely related to a famous circularity objection to phenomenalism raised by Sellars (1963). I discuss how the idealist should respond to this objection in Smithson (manuscript b). 38 In fact, the Cosmoscope described by Chalmers is more complex. But the other features of the Cosmoscope will not be relevant to this essay. 0003203404.INDD 30 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi A New Epistemic Argument for Idealism 31 experiences considered relevant to S2 given our actual evidence; after all, our actual evidence may suggest that the bicycle is in the closet when, in fact, it is outside. Instead, s2 includes the experiences considered relevant to S2 after a certain process of idealized evidence-gathering. I describe how the idealist should understand this process in Smithson (manuscript b).39 The Deference Principle also requires an idealization for the judgment about Si that abstracts away from our contingent cognitive limitations. For example, the idealization should give subjects the ability to remember an infinite number of experiences and allow subjects to entertain thoughts of infinite complexity.40 (v) Counterfactual conditionals: The Deference Principle should not be interpreted as saying that Si is true in some possible world W iff human subjects in W would (ideally) judge that Si is true when presented with si. 41 On this reading, the Deference Principle would make truths about objects very subjective; it would imply, for example, that if humans were to make different judgments about an object's color, then the object's color would be different. The correct reading is: Si is true in some possible world W iff actual human subjects-using their concepts as they actually do-would (ideally) judge that Si is true in W when presented with si. (vi) Neutrality: The Deference Principle constrains how the idealist views the relation between objects and experiences. But this constraint can be met by different underlying metaphysical views. For example, a phenomenalist might view the Deference Principle as implicitly specifying how objects are logically constructed from sense data. Other idealists might instead view the Deference Principle as specifying how facts about experiences metaphysically ground facts about objects. On my own preferred semantic version of idealism ("edenic idealism"-see Smithson (manuscript a)), the Deference Principle specifies how counterfactual experiences select a certain possible world as the one our object discourse is about. 4.3 A Correspondence between Truth and Judgment With the Deference Principle, the idealist assumes that truths about ordinary objects correspond to subjects' (fully informed, idealized) judgments about objects. In this sense, the idealist assumes that judgments about objects are similar to judgments about games. Suppose we are told all of the relevant details about the rules, aims, history, etc. of a practice X. Suppose that, on the basis of all of this information, we judge that X is a game. It is implausible that, nonetheless, X could fail to be a game. For example, when told all of the details about the rules, aims, history, etc. of chess, we judge that chess is a 39 I note that the experiences in si may not be those we explicitly believe to be relevant to Si. It is possible for subjects to have mistaken beliefs about the epistemology of our assertions. 40 For an example of an idealization that would work in the current context, see Chalmers (2012: 63–71). 41 Here,	si is the relevant set of counterfactual experiences supported in W. 0003203404.INDD 31 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi 32 robert smithson game. It is not coherent to suppose that, nonetheless, chess might not really be a game after all. So we can motivate the following principle: Deference Principle for Games: Let Gi be a sentence of the form "X is a game." Gi is true just in case ordinary subjects would (ideally) judge that Gi is true when given a full description of the rules, aims, history, etc. of the practice X in question. Similarly, the idealist's Deference Principle asserts that, if subjects were presented with all of the experiences ordinarily considered relevant to assessing Si, and thereby judged that Si is true, it could not be the case that, nonetheless, Si is false. That there is such a correspondence between truth and judgment is the main lesson of the Oracle thought experiment (see 2.4). This thought experiment shows that, when making judgments about ordinary objects, we do not care about whatever mind-independent external reality gives rise to our experiences; instead, we care about the world as it appears to us. For this reason, we should not expect truths about ordinary objects to outstrip judgments about objects made on the basis of all of the counterfactual experiences in si. 42 5. Conclusion In this essay, I have presented a new epistemic argument for idealism. I have argued that, even if we were to receive evidence that-by the realist's lights-falsifies our judgments about ordinary objects, we would continue to make judgments about objects just as we did before. I then argued that the best response to this puzzle is to conclude that truths about objects do not outstrip truths about our experiences in the ways that realists typically suppose. In the second half of the essay, I discussed how ordinary epistemology constrains the idealist's own positive metaphysics. If the idealist is to respect ordinary epistemology, she must endorse the Deference Principle as specifying how truths about our experiences determine truths about objects.43 References Berkeley, George. 1948. The Works of George Berkeley, Bishop of Cloyne: Volume 2, A. A. Luce and T. E. Jessop, eds. (New York: Thomas Nelson and Sons). Bernstein, Sara. this volume. "Causal Idealism." 42 Of course, the Deference Principle does not guarantee that all of our actual judgments about objects are correct. One reason for this is that actual subjects only have access to limited evidence. In contrast, subjects in the Deference Principle are presented with all counterfactual experiences relevant to assessing Si. A second reason is that actual subjects have various cognitive limitations: we are sometimes careless in reflecting on the evidence, we have limited memories, and so on. This is why the Deference Principle appeals to an idealization on subjects' cognitive capacities (see 4.2). 43 Thanks	to	Tyron	Goldschmidt,	Thomas	Hofweber,	Marc	Lange,	Kenneth	Pearce,	John	Roberts,	and two anonymous referees for valuable feedback on this essay. 0003203404.INDD 32 8/21/2017 8:20:42 PM Dictionary: NOSD OUP UNCORRECTED PROOF – FIRST PROOF, 08/21/2017, SPi A New Epistemic Argument for Idealism 33 Burgess, John and Rosen, Gideon. 2005. "Nominalism Reconsidered." In Steward Shapiro, ed. The Oxford Handbook of Philosophy and Mathematics and Logic (Oxford: Oxford University Press), 515–35. Chalmers, David. 2012. Constructing the World (Oxford: Oxford University Press). DeRose, Keith. 1999. "Contextualism: An Explanation and Defense." In John Greco and Ernest Sosa, eds. The Blackwell Guide to Epistemology (Oxford: Blackwell Publishers), 187–205. Dowe, Phil. 2000. Physical Causation (Cambridge: Cambridge University Press). Dummett, Michael. 1978. Truth and Other Enigmas (Cambridge,	MA:	Harvard	University Press). Dummett, Michael. 2004. Truth and the Past (New York: Columbia University Press). Foster, John. 2008. A World for Us: The Case for Phenomenalistic Idealism (Oxford: Oxford University Press). Greco, Daniel. this volume. "Explanation, Idealism, and Design." Hirsch,	Eli.	2005.	"Physical-Object	Ontology,	Verbal	Disputes,	and	Common	Sense."	Philosophy and Phenomenological Research 70 (1): 67–97. Mill, John Stuart. 2009. An Examination of Sir William Hamilton's Philosophy (New York: Routledge). Pryor, James. 2000. "The Skeptic and the Dogmatist." Noûs 34 (4): 517–49. Putnam,	Hilary. 1975. "The	Meaning of 'Meaning.'"	Minnesota Studies in the Philosophy of Science 7: 131–93. Putnam,	Hilary.	1981.	Reason, Truth, and History (Cambridge: Cambridge University Press). Russell, Bertrand. 1985. The Philosophy of Logical Atomism (La Salle, IL: Open Court). Sellars, Wilfred. 1963. "Phenomenalism." In Science, Perception, and Reality (New York: Humanities	Press). Smithson, Robert. manuscript a. "Edenic Idealism." Smithson, Robert. manuscript b. "Edenic Idealism and the Incompleteness Objection." Vogel, Jonathan. 1990. "Cartesian Skepticism and Inference to the Best Explanation." Journal of Philosophy 87 (11): 658–66. Warmke, Craig. manuscript. "Numerical Idealism." 0003203404.INDD 33 8/21/2017 8:20:42 PM