Philos Phenomenol Res. 2020;00:1–11. | 1wileyonlinelibrary.com/journal/phpr Memory skepticism alleges that our memory beliefs lack justification.1 More precisely, the memory skeptic claims among other things that when we seem to remember that p, believing that p isn't justified. A central argument for memory skepticism attacks our justification for thinking the faculty of memory is epistemically trustworthy. Memory's epistemic trustworthiness has to do with this faculty functioning in a way necessary for it to provide epistemic justification. Epistemologists of various stripes will understand exactly what it is for memory to be epistemically trustworthy differently. Despite these differences, most have tended to focus on memory's reliability simpliciter-its tendency to produce a preponderance of true beliefs.2 An interpretation we will focus on concerns instead mem1When we speak of "memory beliefs" we include all beliefs the contents of which we seem to remember. Whether or not such a belief constitutes a genuine or only an apparent memory is a further question. Importantly, "memory beliefs" doesn't just include beliefs with contents about the past. After all, one might believe and apparently remember that all dogs are mammals. Further, "memory beliefs" also includes any dispositional beliefs that one has, i.e., any belief that we would typically say is stored in one's memory. 2See, e.g., Frise (2015), Fumerton (1995), Locke (1971), Moon (2017), and Senor (2010). DOI: 10.1111/phpr.12715 O R I G I N A L A R T I C L E Forgetting memory skepticism Matthew Frise1 | Kevin McCain2 © 2020 Philosophy and Phenomenological Research, Inc 1Santa Clara University 2University of Alabama at Birmingham Correspondence Matthew Frise, Santa Clara University. Email: mjfrise@gmail.com Abstract Memory skepticism denies our memory beliefs could have any notable epistemic good. One route to memory skepticism is to challenge memory's epistemic trustworthiness, that is, its functioning in a way necessary for it to provide epistemic justification. In this paper we develop and respond to this challenge. It could threaten memory in such a way that we altogether lack doxastic attitudes. If it threatens memory in this way, then the challenge is importantly selfdefeating. If it does not threaten memory in this way, then the challenge leaves a foundation for an inference to the best explanation response, one we articulate and support. 2 | FRISE and MCCaIn ory's conditional reliability-its tendency to yield true beliefs provided that it initially received true beliefs.3 In this paper we examine the skeptical threat concerning the conditional reliability of the faculty (or faculties) of memory. In other words, our focus is a variety of memory skepticism that threatens any belief that is the output of a belief-dependent memory process. Hence, the variety of skepticism that we are interested in challenges the status of any belief that is sustained by memory as well as any belief that depends upon memory along with other beliefs for its formation. Of course, we do not seek simply to understand this challenge; we also intend to offer a satisfactory response. This does not fully solve the problem of memory skepticism. However, it does three things. First, it blocks an important skeptical threat to memory that has received little attention-the memory skepticism literature rarely discusses memory's conditional reliability. Second, it helps provide a basis for responding to other skeptical threats to memory justification (we leave the task of developing this response for another day).4 Third, it reveals that it is quite difficult to only target memory for successful skeptical attacks. After all, if memory is shown to be conditionally reliable, then one must take on a stronger skeptical position, one that threatens the input beliefs, in order to challenge the justificatory status of memory beliefs. The severity of the threat of memory skepticism makes even a partial response helpful. Richard Fumerton (1995: 35) explains "how much more fundamental [it] is than other epistemological problems" by noting that solutions to these other problems, such as external world skepticism and the problem of induction, all presuppose skeptical threats to memory can be blocked. In addition to being so fundamental, memory skepticism is a broad threat all on its own. Put simply, any belief is held over time or newly formed; if the belief is held over time, memory is responsible for its retention; if 3See Goldman (1979) on conditional reliability. Although there may be serious difficulties when it comes to saying what the relevant sense of reliability is for reliabilism (see Frise, 2018 and Pollock, 1984), we will set them aside here as all that is needed for the present discussion is the intuitive idea of memory being such that it tends to yield true beliefs when its initial belief inputs are true. Exactly which memory systems have both belief inputs and belief outputs is an open, empirical question. Semantic memory has both, and episodic memory may too, and the list may go on. One could discuss the conditional reliability of individual memory systems, but this paper discusses the conditional reliability of memory in general (as the challenge here presents a greater skeptical threat). So, our responses to memory skepticism can mostly avoid discussion of particular memory systems. Of course, it may be that memory in general is conditionally reliable, however, various memory systems are not equally reliable. In fact, it may even be that some memory systems are highly unreliable even though memory is in general conditionally reliable. Consequently, establishing that memory in general is conditionally reliable leaves much work to be done in parsing the reliability of various memory systems. But, that is work for other occasions. 4One other kind of skeptical threat attacks our justification for thinking our particular memory beliefs are accurate. It might seem that this skeptical challenge is the same as the one we're addressing. But the challenges do differ. Granting that memory is conditionally reliable, it could be that the inputs to our memory are unjustified-we could remember things that we unjustifiedly believed in the past. Those who hold that memory preserves the negative justificatory status of the beliefs it preserves (e.g., Goldman, 2011: 259-60 and Senor, 2009) would claim that our memory beliefs are unjustified in this case. As a result, our memory beliefs could be unjustified even if memory works properly (e.g. if p is an input belief, memory will yield p as an output belief). Also, memory skepticism remains a problem if the belief inputs to memory are inaccurate. We see this with Russell's hypothesis, according to which memory works properly, but one comes into existence with a full stock of inaccurate memories. Something similar could also happen in an everyday way if we simply believe something that happens to be false, and we retain the belief via memory. In such a case, memory may be conditionally reliable yet it is likely to yield a false belief because the input belief was false. The skeptic can use this possibility to run a skeptical argument even if one shows the faculty of memory itself to be conditionally reliable. Hence, defending memory's epistemic trustworthiness blocks one argument for memory skepticism, but not all. | 3FRISE and MCCaIn the belief is newly formed, memory may, by supplying key background information or the concepts involved in the belief's content, play a role in its generation; so, memory may be in part responsible for most any belief. The threat from memory skepticism is very broad indeed. 1 | AN ARGUMENT FOR MEMORY SKEPTICISM Our first step is to get clear about the nature of the skeptical challenge. It might be understood to be that of providing reasons for thinking that our faculty of memory works properly. The toughest challenge here, and the one we will undertake, would be to provide reasons that are both non-circular (insofar as this is possible) and good for thinking memory works as we suppose it typically does; it yields true output beliefs when given true input beliefs. This challenge is not easily overcome. After all, it is plausible that any attempt to provide reasons in support of trusting memory will involve relying on memory.5 Before you can finish giving your reasons time has moved forward, and you seem forced to rely on your memory to complete your case in support of memory. In fact, it's plausible that time elapses before you can fully consider a given proposition. It isn't far fetched that you have to rely upon memory of the first part of this very sentence when you read to the end so that you can consider the complete thought expressed here. Consequently, one might worry that we cannot hope to defend memory from the skeptical challenge. One might even think, "you cannot use memory to justify the reliability of memory" because doing so amounts to "blatant, indeed pathetic, circularity."6 The same might be said about using memory to justify the conditional reliability of memory. Putting these concerns more precisely gives us the Argument for Memory Skepticism (M): M1) If S has an undefeated reason for thinking that memory is not conditionally reliable, S's memory beliefs are unjustified.7 M2) If there are no non-circular reasons for thinking that memory is conditional reliable, S has an undefeated reason for thinking that memory is not conditionally reliable. M3) There are no non-circular reasons for thinking that memory is conditional reliable. MC) No memory belief is justified. (M1-M3) Now that we have the skeptical challenge clearly in sight, we will explain important limits to it. After exposing the limits of this skeptical challenge, we will respond to it. 5See BonJour (2010: 169-171), Frise (2015), Locke (1971), Plantinga (1993), Senor (2010), and Weatherson (2015). Some deny this, however – e.g., Hasan (forthcoming) and Harrod (1942). 6Fumerton (1995: 177). 7(M1) appears false if S could have reason to believe that memory can generate beliefs without any beliefs as inputs. If memory can create beliefs anew, the reliability simpliciter of memory, not its conditional reliability, is relevant for the justification of the created beliefs. S could justifiedly doubt memory is conditionally reliable, yet have no justified doubt about its reliability simpliciter, such that not all of S's memory beliefs are unjustified. An unwieldy revision of M gets around this concern, but for simplicity we leave M as is. 4 | FRISE and MCCaIn 2 | RATIONAL SELF-DEFEAT-A NOT SO HELPFUL LIMIT One limit that might come to mind immediately is that memory skepticism is rationally self-defeating. In other words, one might respond to the challenge in the following manner: Rational Self-Defeat Argument (RSD) RSD 1) If the Argument for Memory Skepticism (M) is sound, then no memory belief is justified. RSD 2) If no memory belief is justified, then some of our central beliefs about M (e.g., that it has true premises that entail its conclusion) are unjustified. RSD 3) If M is sound, some of our central beliefs about M are unjustified. (RSD1, RSD2) RSD 4) If some of our central beliefs about M are unjustified, M doesn't provide us with good reasons to accept memory skepticism. RSD C) If M is sound, it doesn't provide us with good reasons to accept memory skepticism. (RSD3, RSD4) RSD may, at first, appeal to some readers. The conclusion of RSD tells us straightforwardly that memory skepticism is rationally self-defeating. Simply put, if memory skepticism is correct, we can't justifiedly believe that it is-not via M, at any rate. In light of this, one might be tempted to respond by pointing out that M can't give us good reason to accept memory skepticism. Since we don't otherwise have good reason to accept it, we shouldn't accept memory skepticism. Although such a response might be tempting, it isn't that helpful. One problem is that memory skepticism might be true even though we aren't justified in believing that it is.8 The main issue is whether we lack justification for our memory beliefs. Accepting memory skepticism may be unjustified, but it doesn't follow that our memory beliefs are justified. In fact, it could be that accepting memory skepticism is unjustified precisely because memory beliefs are unjustified. It could be we have no justification from memory for accepting anything-including memory skepticism. Thus, although memory skepticism does seem to be limited in this way, RSD doesn't get us far when it comes to responding to the memory skeptical challenge. RSD provides no evidence that the conclusion of M is false or that the premises of M fail to support its conclusion; and RSD does not reassure us that memory is conditionally reliable or that we have any of the justification that we, intuitively, believe we have for memory beliefs. 3 | SELF-DEFEAT REDUX-A KEY LIMITATION Our challenge is to provide reasons for trusting our memory. More work must be done. Let's begin by taking a step back. Suppose the conclusion of M is true: we have no justified memory beliefs. Why care? The answer is that this conclusion easily leads us to believe that, although we have memory beliefs, they are all unjustified. And that situation is bad. It would mean that we have a lot of unjustified beliefs. Perhaps all of our beliefs are unjustified. However, M cannot lead to that situation. This is made clear by the following argument: 8Cf. Bernecker (2008: 130-1), Frise (2015), and Fumerton (1995: 52). | 5FRISE and MCCaIn Limited Self-Defeat Argument (LSD) LSD 1) Either memory doesn't work well enough for us to have doxastic attitudes or it does. LSD 2) If memory doesn't work well enough for us to have doxastic attitudes, then we don't have any unjustified memory beliefs. LSD 3) If we don't have any unjustified memory beliefs, then memory skepticism is harmless. LSD 4) Therefore, if memory doesn't work well enough for us to have doxastic attitudes, memory skepticism is harmless. (LSD2, LSD3) LSD 5) If memory works well enough for us to have doxastic attitudes, then memory works at least moderately well-it helps us have information, concepts, and dispositions such that we can have doxastic attitudes. LSD C) Therefore, either memory skepticism is harmless (because we don't in fact have any unjustified memory beliefs) or memory works at least moderately well. (LSD1, LSD4, LSD5) LSD presents the memory skeptic with a dilemma: either memory skepticism raises only false alarms, or there is a limit to how badly memory works. In essence LSD hangs on a simple question concerning the skeptical challenge: does memory work well enough for us to have any doxastic attitudes, like beliefs, at all? Presumably, the answer to this must be "Yes". After all, if we do not have memory beliefs, then it is not the case that we have false or even unjustified memory beliefs. There are no beliefs that could have such defects if there are no beliefs in memory. In fact, if we lack memory beliefs, it may be that we cannot even be mistaken about whether we have memory beliefs or mistaken about whether these beliefs are justified. We would have to believe that we have memory beliefs in order to be mistaken. Having such a belief about memory beliefs would itself require that memory works somewhat well. So, it seems the skeptic is better off admitting that memory works well enough for us to have memory beliefs. Consequently, memory skepticism is limited in an important way. It neutralizes itself if it challenges too much. If memory malfunctions so badly that we lack doxastic attitudes, it follows that we lack defective doxastic attitudes. Still, a worry might remain for LSD4. Even if we lack doxastic attitudes, memory skepticism may still seem to have some teeth because we might have reason to believe various things. Suppose that we have no (doxastically) justified attitudes toward any proposition because memory malfunctions so badly that we lack such attitudes altogether. Still, for many propositions having some attitude could be (propositionally) justified for us. And it seems bad if we have no doxastically justified attitudes while we have propositional justification to believe many things. To make matters worse, it might seem that we suspend judgment toward any proposition we neither believe nor disbelieve. So, in this situation, if we cannot believe any proposition, and cannot disbelieve any either, we therefore suspend judgment toward all propositions. But if we are propositionally justified in believing some propositions, much of this suspended judgment is unjustified. If a badly malfunctioning memory could lead to these bad outcomes, we would seem to have an alarming memory skeptical result. LSD4 would appear false. Fortunately, a badly malfunctioning memory does not lead to these bad outcomes. The case we are considering is one in which memory works so poorly that we cannot even have doxastic attitudes. In such a situation, we would therefore not be the sorts of creatures who could have doxastic justification. But we would also not be the sorts of creatures who could have propositional justification. If our cognitive lives 6 | FRISE and MCCaIn are impoverished beyond our possibly having memory beliefs, they would be impoverished beyond our possibly having justification for having such beliefs. We would lack concepts, categories, or a capacity to string these together into even offline thought. We would be ineligible for propositional justification, just as granite and amoebas are ineligible. Additionally, in order to suspend judgment toward a proposition one must be capable of grasping the proposition, and this requires possessing concepts and grasping the proposition. In the sort of scenario we are considering one lacks concepts and would not even be in a position to grasp propositions, so one could not suspend judgment, much less suspend judgment unjustifiedly.9 A badly malfunctioning memory does not lead to the alarming memory skeptical result. LSD4 is secure.10 RSD and LSD each provide perspective on memory skepticism, revealing some limits. But LSD takes us higher. It provides a better perspective. In order for memory skepticism to present any problem at all, it must be that memory works at least moderately well-at least in terms of retaining information, concepts, and dispositions required for having memory beliefs at all.11As a result, it seems that the skeptic must retreat a little when it comes to the functioning of memory. Admittedly, this is nowhere near a rout. The skeptic is far from being forced to admit that memory beliefs are justified (in fact, that won't be the result at the end of our discussion-we will be arguing for only the conditional reliability of memory). Nevertheless, the skeptic is driven to acknowledge a seemingly minor limitation that's significance has been overlooked until now. And, while this concession might seem a small step back for the skeptic, even this bit of footwork trips the skeptic. 4 | AN EXPLANATIONIST RESPONSE TO MEMORY SKEPTICISM At this point we have good grounds for an inference to the best explanation response to the challenge of memory skepticism. Explanationist Response to Memory Skepticism (ER) ER 1) Memory provides whatever is necessary for our having memory beliefs. ER 2) The best explanation of memory providing whatever is necessary for our having memory beliefs is that memory is conditionally reliable. ER C) Memory is conditionally reliable. (ER1, ER2) 9For discussion of many nuances of suspending judgment see Conee & Feldman (2018) and Friedman (2013), (2017). 10One might think that we can directly introspect that we have doxastic attitudes. Thus, we have support via introspection that memory skepticism is not harmless in this sense. If this is correct, so much the worse for memory skepticism. 11One might worry that it could be that memory forms beliefs using erroneous concepts, or even that the basic building blocks of memory (whatever they might be) are really jumbled. As a result, one might question whether memory operating well enough for us to have beliefs really requires functioning moderately well. There are a couple points to make here. First, beliefs formed using erroneous concepts are still beliefs. They are just beliefs with different propositional content. So, if S forms a belief with an erroneous concept for tree, say, she doesn't actually form a belief about a tree. However, she does still form a belief. And, if her memory works well enough for her to form beliefs (whether the concepts are erroneous or not), it works "moderately well." Erroneous concept possession requires some kind of capacity for mislearning, and we lack this capacity if memory is altogether malfunctioning. Second, the basic building blocks of memory are either so jumbled that we cannot form memory beliefs or they are not. If they are jumbled to this extent, then there is no problem of memory skepticism. If they are not jumbled this badly, and so allow us to have memory beliefs, then that is enough for memory to work "moderately well" in our sense. Thanks to an anonymous reviewer for suggesting these concerns. | 7FRISE and MCCaIn The idea behind the ER is straightforward. LSD leaves just two options, and the ER pursues the option that is more promising for raising the problem of memory skepticism: memory functions in the ways needed for raising the problem of memory skepticism. The ER says part of the best explanation of this functioning is that memory is conditionally reliable. Any rival hypothesis that the skeptic gives will be ad hoc. Suppose memory takes beliefs as inputs. Everyone can agree that memory then stands ready to deliver beliefs as outputs-this is required for memory skepticism to be any threat.12 The simplest thing is for there to be minimal changes from the inputs to outputs.13 After all, changes from the inputs to outputs would require something extra going on, some additional mechanism. Minimal changes make it likely that we end up with truths when we start with truths. Hence, the simplest, non-ad hoc (and, here, best) explanation of memory working well enough for us to have memory beliefs is that memory is conditionally reliable. Any rival skepticism-friendly hypothesis would insist that memory works well in just the ways that the skeptic needs but not in a way that generally leads to true beliefs when starting with true beliefs. This would require the skeptical hypothesis to posit some additional mechanism(s) aside from what is already accepted for there to be memory beliefs. Additional posits of this sort are ad hoc, and they render the skeptical hypothesis more complex than the hypothesis that memory is conditionally reliable. An illustration can help make this clear. Think of a refrigerator. We place some cauliflower in the refrigerator, and a couple hours later when we get it out the cauliflower is still cool. One explanation of this is that the refrigerator is working properly. Another is that the refrigerator works properly when it comes to cauliflower, but it won't keep anything else cool. The latter explanation seems problematically ad hoc. Why think that the refrigerator works properly in just this way, but not generally? We need to elaborate on such an explanation in order for it to be plausible (e.g. something special about cauliflower, some strange mechanism in the refrigerator, etc.). This additional information would make the "cools only cauliflower" explanation more complex than the simple explanation that the refrigerator works properly. In the same way, the "memory works only in the ways skepticism needs" is ad hoc, and elaborating to make it plausible would make it more complex than the simple explanation that memory is conditionally reliable.14 As a result, the hypothesis that memory is conditionally reliable provides the best explanation of the proper functioning of memory that the skeptic is committed to accepting. Thus, we can infer that memory is conditionally reliable.15 What's more, we now have support for a more substantive, though more tentative, conclusion. What is the best explanation of memory being conditionally reliable? It would seem to be that memory works well in general. If memory works well in one area, it is simplest to suppose that memory works well in other areas too. On alternative explanations, despite being conditionally reliable, memory has 12A separate issue that is worth considering is whether beliefs continue to exist in the time between being inputs into memory and being outputs of memory. For our purposes, however, this issue can be set aside because it doesn't bear on the question of which explanation of memory's working well enough for us to have beliefs is best. 13Memory might make changes in ways that enable it to function better. It may be deconstructive and reconstructive in ways that allow it to operate more efficiently or more powerfully. This doesn't undermine our general point here. 14Thanks to Jonathan Vogel for suggesting this way of illustrating our point. 15The ER is similar to the way that some, such as McCain (2016), have appealed to inference to the best explanation to respond to the problem of induction. This shouldn't be surprising, however, if Bernecker (2008) is correct that memory skepticism and the problem of induction are analogous problems. Although there are similarities here, there is at least one important difference. One of the ways that inference to the best explanation is used to respond to the problem of induction is by arguing that inductive inferences (when justified) are really inferences to the best explanation (see Harman, 1965 and McCain, 2016). We aren't suggesting that memory beliefs involve an inference to the best explanation. It's plausible that such beliefs are non-inferential. Still, it could be that memory beliefs are justified because the truth of their content bears certain explanatory relations to the subject's evidence (see McCain, 2014 for more on this general explanationist approach to justification). 8 | FRISE and MCCaIn some substantive defect. But those explanations will be more complex. For example, they will have to posit something that explains why memory functions worse in other areas. And they will have to make sense of why memory's significant flaws in those areas do not compromise its conditional reliability. The simpler and better explanation is that memory works well in general. One might be concerned, however, that LSD and the ER prove too much. After all, it appears that one could offer seemingly structurally identical arguments that center on any faculty that faces skeptical threats. One could, for example, offer an argument like LSD that begins with "Either perception doesn't work well enough for us to have doxastic attitudes or it does," and concludes "Either external-world skepticism is harmless (because we don't in fact have any unjustified external-world beliefs) or perception works at least moderately well." The concern is that we would have a formula for too easily addressing too many skepticisms. What's more, one could offer arguments seemingly structurally identical to LSD that support intuitively bad faculties. For example, suppose there is a belief-producing wish-fulfillment faculty. It might seem that, if LSD is good, one could also begin an argument with "Either wish-fulfillment doesn't work well enough for us to have doxastic attitudes or it does," and concludes "Either wish-fulfillment skepticism is harmless (because we don't in fact have any unjustified wishful beliefs) or wish-fulfilment works at least moderately well." If these arguments are good, one could then argue, in parallel to the ER, that the best explanation of perception or wish-fulfillment working as well as they do is that each is conditionally reliable. These arguments appear to parallel LSD. But, as the reader on memory skepticism will be aware, appearances can mislead. The apparently parallel arguments run into trouble with LSD 5, which states: "If memory works well enough for us to have doxastic attitudes, then memory works at least moderately well." A parallel premise about perception would be "If perception works well enough for us to have doxastic attitudes, then perception works at least moderately well." But this is false. We can have doxastic attitudes regardless of how well perception works, but this is not the case for memory. Suppose memory functions well enough for us to have doxastic attitudes. Trivially, then, perception works well enough for us to have doxastic attitudes; how perception functions does not prevent us from having doxastic attitudes. But the consequent of the parallel premise could still be false: perception does not work moderately well. The same could be said for parallel arguments concerning wish-fulfillment, or what have you. The parallel arguments would not be sound, and so there is no concern about LSD and the ER proving too much if they prove anything at all. 5 | THE THREAT OF CIRCULARITY One might worry that the skeptical challenge still presents a problem. Some key premises of M mention "non-circular reasons for thinking that memory is conditionally reliable". However, we rely on memory in order to develop the ER. In fact, we can't even understand the ER or LSD without using memory. We have to use memory to understand the premises of these arguments and to recognize that the premises of the arguments entail their conclusions. Isn't this problematic? There are two points to make in response to this concern. First, it's not clear that the use of memory in understanding LSD and the ER renders this way of responding circular-the work in supporting the conditional reliability of memory isn't being done directly by memory or by a clear assumption about its conditional reliability.16 It's not like, say, arguing that we should trust memory because we remember times that memory worked properly, or because we remember things that we are now confirming. 16See Hasan (forthcoming) for a different response to a similar objection. | 9FRISE and MCCaIn Instead, we are simply thinking about arguments that show that memory skepticism is mistaken, and this mere thinking requires us to use our memory. Memory isn't playing a role in justifying the premises of these arguments, nor is it playing a role in justifying the inference from the premises to the conclusions of the arguments. Furthermore, there is no assumption that memory is reliable here. After all, we aren't assuming that memory tends to produce more true beliefs than false beliefs. Granted, we are assuming that memory allows us to form some beliefs (beliefs about whether the premises of these arguments support their conclusions). However, this doesn't seem to go beyond the skeptic's assumption that memory works well enough for us to form the doxastic attitudes necessary for memory skepticism to be a threat. There is no direct support of the conditional reliability of memory by memory here. Rather, our use of memory is indirect in the sense that it is only allowing us to think about the arguments. If our indirect use of memory here falls short of circularity, premise (M3) of M is false; the ER provides a non-circular defense of memory's epistemic trustworthiness.17 Second, even if there is circularity at play here, it's not a problem. Memory is special because it is a fundamental faculty, perhaps even more so than any sense perceptual faculty. We can't form many beliefs, let alone retain them, without using memory. We cannot even engage in any temporally extended cognitive activity without some memory processing. If a faculty is fundamental, engaging in any defense of it must be circular in the sense of having to use that faculty when thinking about the threat to it and when providing its defense (at least to some extent). After all, the mere fact that a faculty is fundamental guarantees there is no more fundamental faculty that can be used to show that it is reliable or conditionally reliable. Any other faculties will at best be equally fundamental. So, if F is a fundamental faculty, either a defense of its reliability will rely directly upon F or it will rely upon another fundamental faculty, F*, which will in turn be supported directly by itself or yet another fundamental faculty. Once we have reached the level of fundamental faculties either we have a very small circle, F supports F, or a larger circle F supports F* which supports F** which supports F, or a larger circle still. Since there are a finite number of fundamental faculties, a circle of support at this level is unavoidable. Consequently, engaging in any defense of memory must be circular in the sense that it requires using memory-doing so is, after all, a temporally extended cognitive activity. If a defense of a faculty must be circular in virtue of its fundamentality, the defense's circularity doesn't thereby undermine it.18 Therefore, the fact that this defense of memory is circular doesn't thereby undermine it. Importantly, acknowledging the circularity that memory's fundamentality necessitates doesn't amount to claiming that since memory is fundamental it can be used to directly justify thinking that memory is conditionally reliable. Instead, the sort of circularity that memory's fundamentality necessitates when defending memory is simply that we must use memory to engage in the thinking required for (a) appreciating the threat that memory skepticism is thought to pose and (b) understanding responses to that threat. While we are acknowledging that there may be unavoidable circularity of a sort when defending the conditional reliability of memory, we are not thereby treating memory as a justifier for the claim that memory is conditionally reliable. Hence, the circularity that arises from using memory to engage in defending memory's conditional reliability is insufficient to justify doubting that memory is conditionally reliable. Of course, this means that premise (M2) of M is false. Either way, our use of 17A further reason to doubt (M3) is that memory is not a natural kind (Michaelian, 2011). Ordinary uses of 'memory' pick out any of a number of systems, not one overarching system. It is possible to defend the conditional reliability of one memory system by using another memory system. Memory (of some kind) would be employed in the defense of the conditional reliability of memory (of another kind). But this defense would be non-circular, as no memory system is defending its own conditional reliability. We don't press this line of attack on (M3) here because to do this effectively might require firmer answers to the empirical question mentioned in footnote 3. 18See Matheson (2012) and McCain (2016) for defense of this point. 10 | FRISE and MCCaIn memory here is unproblematic. M is unsound, and we have a good response to this memory skeptical challenge. Additionally, ER may provide a foundation for accounting for how it is that our memory beliefs are justified-inference to the best explanation may play a key role. This additional point is beyond the scope of our present concerns, however. 6 | CONCLUSION Arguments for memory skepticism can be pressed on two fronts. We've seen here that the skeptic's attack on one of those fronts is ineffective. LSD reveals a significant limitation with which the skeptic must contend. The ER builds upon the insights of LSD, rebuffing the skeptic's attack. Of course, as we noted above, the skeptic can still press attacks on another front. So, there is more work to be done. Fortunately, explanationist responses, like the ER, may offer promising defenses.19 ORCID Matthew Frise https://orcid.org/0000-0002-1311-2963 Kevin McCain https://orcid.org/0000-0002-2447-4046 REFERENCES Bernecker, S. (2008). The metaphysics of memory. Dordrecht: Springer. BonJour, L. (2010). Epistemology: Classic problems and contemporary responses. Lanham, MD: Rowman & Littlefield. Conee, E., & Feldman, R. (2018). Between belief and disbelief. In K. McCain (Ed.), Believing in accordance with the evidence: New essays on evidentialism (pp. 71–89). Cham: Springer. https://doi.org/10.1007/978-3-319-95993 -1_6 Friedman, J. (2013). 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