My thanks to Julia Smith, Louis Doulas, Bill Lycan, and Matthias Steup for their incisive and challenging comments on my book, Radical Skepticism and Epistemic Intuition (hereafter, RS&EI). It is a privilege for me to have my book scrutinized by such excellent philosophers. I will not be able to reply to everything they say, but I will do my best to address many of their most important concerns.
1. Smith
Smith’s summary of my views on epistemic intuitions as the evidential basis of our anti-skeptical beliefs is helpful and accurate. However, as summaries often do, it leaves things out. I will first explain what is left out and then respond to her charge that my talk of intuitions as evidence is at odds with our ordinary ways of speaking and thinking about evidence. After that, I will address two concerns she raises about what she says my views imply about disagreement.
Smith (Reference Smith2024, 513–515) rightly points out that I think of intuitions as seemings,Footnote 1 that I think of seemings as evidence, and that I think a key characteristic of evidence is that it is that on which our paradigmatically justified beliefs are based. But this leaves out some important parts of my view on evidence and intuitions. For starters, I note that the term “evidence” is ambiguous. The term can be associated with the phenomenal conception of evidence that I employ in RS&EI, where evidence consists of conscious mental states in response to which we often form beliefs. But it can also be used to refer to objects and events presented in a court of law or to propositions that confirm or best explain the hypotheses they support (Bergmann, Reference Bergmann2021, 10–12). (Because these different meanings are all related, we can think of the term “evidence” as a polyseme rather than a mere homonym.Footnote 2) I emphasize that, although I’m employing the phenomenal sense of “evidence,” the propositional sense and the object-event sense of “evidence” are “perfectly acceptable ways to use the term” (Bergmann, Reference Bergmann2021, 11). In addition, I also make clear that, according to the phenomenal sense of “evidence,” there are kinds of conscious mental states besides seemings that count as evidence (Bergmann, Reference Bergmann2021, 11 & 24–25).
Thus, when Smith (Reference Smith2024, 516) speaks of problems faced by views that say “one’s evidence is exhausted by one’s seemings,” she is not speaking of my view or of all views that employ the phenomenal conception of evidence. Moreover, given my view that “evidence” is a polyseme, when she says that ordinary talk of evidence—in the object-event sense of “evidence”—counts against my way of thinking, she is not taking into account that I say such talk is perfectly acceptable. Contrary to what she says (Smith, Reference Smith2024, 516), I do not need to employ an “error-theoretic” explanation of our common ways of speaking about evidence. Instead, I can (and do) offer a “polysemy” explanation of our common ways of speaking about evidence.
Similarly, in the Staffel-inspired example, discussed by Smith (Reference Smith2024, 516–517), of Sam the detective, I need not deny that it is natural to say that Sam’s evidence does not change between Wednesday night and Thursday morning. This is because it is often natural and appropriate in certain contexts to use the term “evidence” in the object-event sense. But we can, of course, talk about that same case using the phenomenal sense of “evidence.” And doing so would help explain why Sam’s overnight change in view can be rational, even though there is no change in Sam’s “object-event” evidence. My choice to focus on the phenomenal sense of “evidence” is not intended as an objection to using the term “evidence” in the perfectly acceptable object-event sense. Both uses are often normal and appropriate. What is required is clarity about which sense of the term we have in mind, not a commitment to always use the term in just one way.
Consider next Smith’s suggestion (Reference Smith2024, 517–518) that it is a problem for my view if beliefs are based on things such as hopes and biases that are not evidence. I have said that (phenomenal) evidence is that on which our paradigmatically justified beliefs are based (Bergmann, Reference Bergmann2021, 11). And I have said that S’s belief B is based on E only if “E is a mental state of S’s that causally contributes to the formation of B in virtue of S (or S’s belief-forming mechanisms) treating E as evidentially supportive of B.”Footnote 3 However, I am not committed to the view that all mental states on which beliefs are based count as phenomenal evidence. The claim of mine that Smith seems to be targetingFootnote 4 is that:
C: (i) propositional evidence and (ii) object-event evidence are distinct from phenomenal evidence, because paradigmatically justified beliefs aren’t based on (i) and (ii), whereas they are based on phenomenal evidence.Footnote 5
But given what I said earlier in this paragraph about the basing relation, if beliefs are based on hopes or biases, then hopes and biases—unlike (i) and (ii)—are mental states. And even if a belief can be based on such hopes and biases without them counting as phenomenal evidence, that does not count against C.Footnote 6
Finally, consider Smith’s point (Reference Smith2024, 518) that a person can have evidence (in the phenomenal sense) but fail to base any beliefs on it. She suggests that this is a problem for my view, perhaps because she thinks my view entails that something is not evidence if no beliefs are based on it. It is true that I emphasize that the most distinctive (although not the only) characteristic of evidence is that it is that on which our paradigmatically justified beliefs are based (Bergmann, Reference Bergmann2021, 11). However, I also say that we can have evidence that makes our beliefs propositionally justified even if those beliefs fail to be doxastically justified due to the fact that they are not based on the good evidence we have (Bergmann, Reference Bergmann2021, 9).
Let me turn next to two concerns Smith has about what she thinks my views on intuitions and evidence imply about disagreement. To set up the first concern, I say I can rationally demote alleged epistemic peersFootnote 7 who disagree with me when my epistemic intuitions strongly support the goodness of my own evidence (and response to it) but not the goodness of the evidence (or response to it) of those who disagree with me (Bergmann, Reference Bergmann2021, 243–50). One might think (although Smith does not press this point) that this is a bad thing because it makes it too easy to rationally demote alleged peers who disagree with me. This easy demotion may not be a problem in disagreements about radical skepticism. However, one might view it as more problematic if it is a go-to response in cases of disagreement with intelligent, wise, and decent people about moral, political, and religious matters.
To be clear, I do not think it is always easy to rationally demote in these latter sorts of disagreements, in part because in many such cases, one might not have epistemic intuitions strongly favoring one’s own evidence (and responses to it) over the evidence (and responses to it) of one’s alleged peers. Nor am I committed to the rationality (in every sense of “rationality”) of demoting one’s alleged peers even when one does have epistemic intuitions favoring one’s own evidence and response to it. This is because one’s beliefs might be internally rational as responses to one’s epistemic intuitions and yet externally irrational due to the fact that one epistemically should not have those epistemic intuitions. (A belief is internally rational when the belief-forming process is going as it epistemically should downstream from—i.e., in response to—one’s conscious mental states; a belief is externally rational when that process is going as it epistemically should both upstream and downstream from one’s conscious mental states.Footnote 8) This is what I suggest is true of certain radical skeptics, who disagree with me and have epistemic intuitions that lead them to demote me.Footnote 9
Smith does not raise objections to any of this. But the “easy demotion” idea is in the background when she presents (Smith, Reference Smith2024, 520) her first concern about the implications of my views on disagreement, which is that my approach “discourages dialogue” and “discourages mutual efforts to understand and persuade.” She says it discourages these things because my approach allows that even in the best cases of disagreement (i.e., those that persist after long, careful, and clear discussion with an intelligent, informed, and generous interlocutor), you might determine that the only mistake the other person is making is having the wrong seemings, both about the topic of your disagreement and about which seemings are the better ones to have on this matter. How can reasoning with one another bring about changes in such seemings so that we no longer disagree? Dialogue and persuasion seem powerless to help.
The first thing to say is that even if I’m right about what happens in the best of the realistic cases of deep disagreement between fallible people, there is still much to say in our usual cases of disagreement, which are typically not of the best kind. Instead, they are cases where the disputants have not yet reached the point of clear mutual understanding about precisely where they disagree (in their intuitive seemings) after sharing all their relevant evidence and appreciating all of the points that the other has to make.Footnote 10
However, suppose we focus on disagreements that are among the best, where the disputants are clear about their rock-bottom intuitive disagreements about a political, moral, or religious topic. Does my approach discourage dialogue and mutual efforts to understand and persuade in such situations? No.Footnote 11 It is true that my approach recognizes that further efforts to understand and persuade will be difficult and maybe even unlikely to be successful. That is just being realistic. Nevertheless, further dialogue can still be valuable and might even result in a rational change of intuitions in the disputants. It is true that people’s intuitions often do not change. However, they can change—in strength, in clarity of focus, and in overall import. For example, a person may have misleading defeaters for an intuition that is rational—misleading defeaters that arise in complicated ways that are very difficult to reliably discern or intentionally correct. Perhaps you can escape these misleading defeaters by coming to see that a view you found counterintuitive need not be held in the problematic way you supposed it must. Or by coming to see that the counterintuitive implications of your view are worse than those of an opposing view. Or by having previously-unnoticed-by-you nonevidential and misleading influences on your perspective exposed or somehow extinguished (possibly without realizing how or that this has happened). Changes of this sort could be rational in the sense that it need not be contrary to proper cognitive function for such changes to occur, even if they are not based on evidence or reasons (which is not to say such changes could not be so based). It is true that there is typically no guaranteed or straightforward route from philosophical engagement to such rational changes of intuition. However, there are potential pathways from such engagement to the occurrence of mental processes in oneself or others that give rise to these sorts of rational change of intuition. This possibility is enough to make sensible people feel cautiously optimistic about philosophical dialectic, viewing it as worthwhile. It may be helpful to yourself or others, even if not to all, and even if it is not guaranteed to be helpful to any.
Smith’s second concern about the implications of my views on disagreement is that, given my views on the evidential role of intuitions in cases of disagreement, it is problematic for me to conclude, as I do, that disjunctivists, who reject the New Evil Demon (or NED) intuition, thereby have a response to radical skepticism that is inferior to my own commonsensist response. (The NED intuition is the intuition that you and your demon-victim twinFootnote 12 are equally justified in your perceptual beliefs because your evidence for them is equally good.) I say that, by rejecting the NED intuition, disjunctivists fail to take the skeptical challenge as seriously as it deserves to be taken.Footnote 13 Smith replies that this complaint has force only if we rely on epistemic intuitions that align with the NED intuition. The problem, Smith says (Reference Smith2024, 520), is that disjunctivists might not have such epistemic intuitions, in which case their response to skepticism may well be, by the lights of my intuitionist particularist framework, as evidentially supported as my own commonsense response to skepticism, in which case my response is not better after all.
By way of reply, note first that, as I say in RS&EI, even those who deny the NED intuition feel some discomfort in doing so, which suggests that they share the NED intuition to at least some degree.Footnote 14 But let us consider disjunctivists who do not share the NED intuition.Footnote 15 What do I say about them? In my view, the beliefs based on the different epistemic intuitionsFootnote 16 had by me, the skeptic, and the anti-skeptical disjunctivist can all be internally rational. Footnote 17 But I am also inclined to think the skeptic’s distinctive epistemic intuitions are irrational, in which case their beliefs based on them are externally irrational. Footnote 18 As for the disjunctivist’s distinctive epistemic intuitions, I am inclined to think that they are not as rational as the ones I have, in which case the disjunctivist’s beliefs based on those intuitions are not as externally rational as mine are on these matters. (I am more confident that the skeptic is mistaken than I am that the disjunctivist is mistaken.) In short, my intuitionist particularist framework might commit me to allowing that the disjunctivist’s views can be as internally rational as my views; but it does not commit me to allowing that the disjunctivist’s views are as externally rational as my views. Thus, my intuitionist particularist framework allows me to say that my favored response to skepticism is better than the disjunctivist’s response.
2. Doulas
Doulas’s thoughtful comments focus on what I say about cases of deep-seated disagreements between intelligent, informed thinkers of good will—disagreements that seem to end in stalemates. These are cases where each person (i) has strongly held intuitions that are opposed to those had by the other person, (ii) thinks the other’s intuitions are misguided, and (iii) thinks it is not very likely that the other’s intuitions can be altered by any further evidence or arguments that can be provided. On the one hand, Doulas is somewhat sympathetic to my description and diagnosis of these kinds of cases, at least insofar as I say they amount to fundamental intuition standoffs (between intelligent, informed, and decent thinkers), and that successfully proselytizing the other, in such situations, via persuasive arguments is probably hopeless.Footnote 19 On the other hand, Doulas has some concerns about my intuition-based steadfastness, which involves standing my ground in the face of such fundamental disagreements and viewing my opponent’s intuitions as externally irrational and objectively epistemically worse than my own (even though I realize they will think the same of me).
Doulas raises three main concerns about my steadfastness in these fundamental intuition standoffs. First, he thinks my steadfastness is too isolationist (Doulas, Reference Doulas2024, 526–527). Because of its inward-looking focus on my own intuitions, it lacks the kind of corrective mechanism for avoiding error that is provided by a more public and intersubjective commonsense approach that relies on consensus.Footnote 20 Second, he thinks my steadfast approach to disagreement is too optimistic—particularly in my response to the charge that my steadfast approach encourages pessimism about philosophical dialectic by discouraging mutual efforts to understand and persuade.Footnote 21 Third, he thinks my steadfastness is too immodest. As he puts it (Doulas, Reference Doulas2024, 528), he “cannot help but recoil from” the “epistemically immodest” aspects of my sort of steadfastness, where I take my own intuitions to be “objectively more rational … than others” and to “serve as evidence … for the truth of [my] philosophical beliefs.”Footnote 22
Regarding the first concern about being too isolationist, I think that it is wise (and consistent with both my autodidactic approach and my steadfastness in the face of standoffs about fundamental intuitions) to learn from the evidence I have about the errors in the intuitions had by me and others and to seek to gather more evidence of this kind by conversing with and listening sympathetically to those who disagree with me.Footnote 23 In light of what this activity reveals about the possibility of my own error, I agree that I should be appropriately cautious about endorsing my own intuitions.Footnote 24
I also recognize that it is possible for humans to have or lack evidence in ways that they would not if things were going as they epistemically should upstream from (i.e., causally prior to) their experience. For example, it is possible to have a sensory experience one should not have that is caused by a deceptive demon; it is also possible to lack (for whatever reason) the strong anti-skeptical intuitions one should have. What is the epistemically appropriate response to recognizing these possibilities? Is it to worry that my evidence is illusory or problematically incomplete on the topic of radical skepticism? My strongest epistemic intuitions (which I confidently trust) say “no.” They tell me I should (i) trust both my perceptual experience and my anti-skeptical intuitions and (ii) think it is the skeptic who either has problematic epistemic intuitions or lacks appropriate ones. My strongest epistemic intuitions tell me I should do this even if I learn that the skeptic thinks similarly of me.Footnote 25
This approach might come across as an inward-looking one similar to Descartes’s in the Meditations. However, as Doulas notes, I am an externalist in epistemology insofar as I think of both internal and external rationality in externalist terms and as depending on proper function.Footnote 26 Nevertheless, just as proper function for humans dictates that their perceptual beliefs are typically based on conscious mental states in the form of sensory experiences and perceptual seemings, so also it dictates that their epistemic beliefs (about what is rational and what is required for rationality) are typically based on conscious mental states in the form of epistemic intuitions. Thus, despite my emphasis on epistemic intuitions and the autodidactic approach, my view is externalist in a way that the views of Descartes and contemporary phenomenal conservatives are not (Bergmann, Reference Bergmann2021, 159–70).
Doulas (Reference Doulas2024, 527–528) views Moore’s commonsense approach favorably because it satisfies an outward-looking publicity criterion that relies on consensus. But my experience of seeing a table is no more or less public than my experience of having an epistemic intuition that I should trust my sensory experience of the table. In each case, I can report these experiences to others, letting them know what I see and what I intuit. If I learn via the testimony of others that they see and intuit these same things, then both my perception and my intuition are thereby intersubjectively grounded and satisfy a publicity criterion that relies on consensus.Footnote 27 My reliance on intuitions does not count as inward-looking isolation if I learn that my intuitions, like my perceptual experiences, are widely shared. The fact that one’s perceptual evidence is more widely shared than one’s intuitional evidence is compatible with the latter being sufficiently widely shared among others whose belief-forming abilities one respects.
Moreover, I agree that, when thinking about philosophical topics, consensus and a shared perspective with others matter for the rationality of one’s intuitions, even if it is not all that matters. How much consensus is there about which intuitions one should have? The answer depends on which kinds of intuition are at issue. Consider three kinds of intuitions on which we rely in thinking about philosophical topics. First, there are pre-theoretic commonsense intuitions, including not only those that oppose radical skepticism about perception and memory, but also intuitions that we sometimes have genuine leeway in our behavior, that we are sometimes ultimately responsible for our actions, and that some actions (i.e., ones that seem horrifically evil) are, in fact, morally wrong. Second, there are philosophically informed commonsense intuitions that arise only after one engages in philosophical reflection, but which naturally arise in the minds of philosophical neophytes entrenched pre-theoretically in common sense, once they clearly understand the issue in question. Examples here include the intuitions that every proposition is true or not true, that a set such as the null set is not the kind of thing that can be true or false, that my modal properties are not reducible to the non-modal properties of someone distinct from me, and that accidentally true belief is not knowledge. Third, there are philosophical intuitions that are further removed from common sense—such as the intuitions that one could be conscious without a brain, that for every property there is a set of things with that property, and that if A and B are composed of the same parts, then A is identical with B. Pre-theoretic commonsense intuitions are the strongest and most widely shared; philosophically informed commonsense intuitions are nearly as strong and widely shared. Intuitions of these first two kinds carry more evidential weight and better satisfy the outward-looking publicity criterion than philosophical intuitions of the third kind, which are further removed from common sense. In RS&EI, I rely most heavily on the first two kinds of intuitions for precisely the reason Doulas mentions, having to do with greater (even if not universal) consensus. For these reasons, I deny that my autodidactic steadfastness in the face of an intuitional standoff is too isolationist.
Let us turn next to Doulas’s second concern—that my steadfast approach to disagreement is too optimistic. The thought here is that, in response to the charge that my steadfast approach encourages pessimism about philosophical dialectic by discouraging mutual efforts to understand and persuade, I am unrealistically optimistic. I just mentioned, in response to Doulas’s first concern, that I agree with him that it is wise to gather and attend to evidence that intuitions (had by oneself and others) are mistaken. Gathering this evidence involves interacting with others with whom you disagree, to become clearer about whether and how your fundamental intuitions differ. So, there is at least that motivation for engaging in philosophical dialogue and efforts to understand others. However, Doulas is also concerned that, even if one gathers and ponders such evidence, changes in fundamental intuitions are too rare to warrant optimism about movement toward agreement.Footnote 28
Here’s why I’m still optimistically hopeful about the value of dialogue and efforts at mutual understanding. For starters, as I mentioned earlier in response to Smith, many cases of deep disagreement are ones where the disputants have not yet reached the point of sharing all their relevant evidence, appreciating all the points that the other has to make, and seeing more clearly where they disagree, intuition-wise. Dialogue and efforts at mutual understanding can obviously help with this. They can also help those on both sides of a fundamental disagreement see that many people on the opposing side are intelligent, informed, and decent people who remain steadfast in the face of disagreement. And this can make one less likely to adopt implausible explanations of those with whom one disagrees—explanations such as that they are unintelligent, uninformed, or morally inferior. You might still wonder why they continue to have intuitions—ones you think are problematic—in support of their steadfast opposition to your view. But you might also reduce your confidence in your own intuitions. Perhaps it is unlikely that your confidence or theirs will be reduced enough to result in a switch in fundamental intuitions. Nevertheless, such an admittedly unlikely change can still be likely enough to make hope for such a change a rational basis for continued engagement in philosophical dialogue. Even if they are rare, such changes in fundamental intuitions do sometimes happen, as we see in occasional cases of conversion to or from religious or moral or philosophical perspectives in adults who have long been invested in their views and later give them up. And even when there is no such change, there are other benefits to continued philosophical dialogue, such as understanding oneself and others better, increasing one’s humility and appropriate respect for others, and removing errors and weaknesses in one’s controversial views.
Doulas’s final concern is that my steadfastness is too immodest. Footnote 29 For the sake of argument, I will grant that it is, in some sense, epistemically immodest to think that you are right, that your intuitions are ones it is epistemically good to have, that those who disagree with you are mistaken, and that their intuitions in support of their mistaken views are ones it is not epistemically good to have. But the only way to avoid this kind of epistemic immodesty, from which Doulas says he recoils, is to refrain from making any controversial evaluation of any controversial view that is held by an intelligent, informed, and decent person. But refraining from such things is not easy. For example, when Doulas says that he recoils from the epistemic immodesty of my steadfastness, one gets the impression that he is implicitly objecting to my position and indicating that my steadfastness is in some way objectively inappropriate. However, the claim that my steadfastness is objectively inappropriate is itself a controversial view, one with which intelligent, informed, and decent people disagree. If Doulas were to endorse that controversial evaluation of my steadfastness (which I and others think is not objectively inappropriate), he would be doing the very thing from which he recoils: he would be steadfastly endorsing a controversial view in the face of an intuition standoff with intelligent, informed, and decent people; and he would be viewing those whose intuitions favor my steadfastness against the skeptic as having intuitions inferior to his (Doulas’s) own contrary intuitions. Doulas can avoid doing the very thing from which he recoils if he makes no controversial evaluations of anyone’s view on a controversial topic (which might require him to distance himself from his own recoiling—saying it just happened to him, and that he does not endorse it). But that is an uninteresting way to engage the controversial views of others, and it is well-nigh impossible to avoid such controversial evaluations, at least in our thoughts, about the controversial views of others. And I assume Doulas recoils as much from such immodest thoughts as he does from expressions of those thoughts.
Of course, one might offer controversial evaluations of the controversial views of others (worthy of respect) without acknowledging that one is doing something in the same category as that from which Doulas recoils. But this requires a lack of forthrightness or perceptiveness about one’s own steadfastness in the face of fundamental intuition standoffs and about one’s own habit of evaluating the intuitions of others as inferior to one’s own. In particular, it requires this lack of forthrightness or perceptiveness about one’s own steadfastness and assumed superiority while one is complaining that others are guilty of this sort of steadfastness and assumed superiority.
I should note that I am sympathetic to Doulas’s recoil from epistemic immodesty, with two caveats. First, I acknowledge that the recoil I endorse is itself a kind of epistemic immodesty (at least if epistemic immodesty is understood as explained above, which—as I said—I grant for the sake of argument). Second, I think of the recoil I endorse as being due to an aversion to worse kinds of epistemic immodesty, not to the kind involved in the recoil itself (or in my steadfastness in the face of fundamental intuition standoffs). Because I recoil against those worse kinds of epistemic immodesty, I’m motivated to engage only in the kind of epistemic immodesty that I think is nearly inescapable and to do so in the most modest, rational, and forthright way possible.Footnote 30 Obviously, there is the danger of straying from the appropriate kind of immodesty into the inappropriate kinds of immodesty from which one recoils. All one can do is try one’s best not to cross that line.
3. Lycan
Both Lycan and I are strong supporters of the commonsense tradition. But Lycan also sharply disagrees with parts of my book. I will focus on the disagreement he emphasizes most, which is over whether there are good inference-to-the-best-explanation (or IBE) arguments against radical skepticism about our perceptual beliefs.Footnote 31 I say that, contrary to the proponents of such IBE arguments, the standard realist explanation of our perceptual beliefs is not a better explanation than the radical skeptic’s evil demon hypothesis. Lycan strongly disagrees. This matters because my opposition to Lycan’s view on this topic plays some role in my case for preferring a commonsense response to radical skepticism (Bergmann, Reference Bergmann2021, 5–6 & 111).
Lycan and I agree that the evil demon hypothesis, which I’ll call “EDH,” is far less plausible than the standard hypothesis, which I will call “SH”. SH says that things are pretty much as they perceptually seem (where this includes the fact that it seems, based in part on perception-based science, that perception is in certain limited ways mistaken). EDH says that a powerful person has a strong desire to radically deceive me by arranging for me to believe that SH is true and getting me to have extremely misleading perceptual seemings. Lycan and I both think that SH is worthy of confident belief, and that EDH deserves to be dismissed as unreasonable. The main source of our disagreement has to do with how IBE is supposed to work—both in general and in arguments against radical skepticism about our perceptual beliefs.
Let us start with IBE in general. As I’m understanding IBE, what makes it a form of inference worth relying on is the thought that the best explanations—what are sometimes called “the loveliest explanations”—are more likely to be true than competing explanations that are worse.Footnote 32 As Peter Lipton emphasizes, it is because the loveliness of the best explanations indicates likely truth that IBE is a good form of inference.Footnote 33 Lycan denies this. He says (Lycan, Reference Lycan2024, 537):
IBE proponents are certainly not assuming that “loveliness” is indicative of any such thing [as likely truth]. For us, “loveliness” is the fundamental epistemic value. And to insist that we need to defend some connection with a more demanding value would simply beg the question in favor of a competing epistemological theory.
This perspective on IBE strikes me as implausible. I can certainly see that IBE does not guarantee that the best explanations are true, and that it can be reasonable to hold false beliefs formed via IBE. However, suppose you came to think that beliefs formed via IBE are not likely to be true. That would give you a defeater for your beliefs formed via IBE. And it would do so even if you continued to think that the explanations you believed via IBE had the feature of loveliness. It is not reasonable to believe lovely explanations when you also think they are not likely to be true. This supports my view that proponents of IBE should not say that loveliness is the fundamental epistemic value, insofar as that conflicts with saying that “IBE is worth relying on because loveliness is indicative of likely truth.”
Let us turn from IBE in general to IBE as it features in arguments against radical skepticism about our perceptual beliefs. The claim of such arguments is (or should be) that when we compare SH and EDH, we can see that SH offers a better explanation than EDH of certain features of the evidence for our perceptual beliefsFootnote 34 and that it does so in a way that indicates that SH is more likely than EDH to be true. In RS&EI, I object to arguments of this kind. As noted earlier, independently of IBE arguments against radical skepticism, I dismiss EDH because it is ridiculous. It is not a view I take seriously. However, when I dismiss EDH as ridiculous, the basis of my dismissal is not that it fails to do a good job of explaining the relevant features of our perceptual evidence.
If we want to rely on IBE in discerning whether SH is more likely to be true than EDH (in virtue of being a better explanation than EDH of certain features of our perceptual experience), there are some important ground rules we need to follow. First, we must set aside what we know via perception. Second, we must set aside what we know via other sources (such as epistemic intuition) about the relative merits of SH and EDH. After all, we are trying to see what we can learn from IBE about the relative merits of SH and EDH, as a prelude to trusting our perceptual experience. Yes, we can tell via epistemic intuition that EDH is to be dismissed and SH is to be viewed as very plausible. However, that way of choosing SH over EDH does not rely on IBE.
Thus, the question is this: if we set aside what we know via perception and what we know via epistemic intuition about the relative merits of SH and EDH, what does IBE tell us about the relative merits of SH and EDH as truth-indicative explanations of certain features of our perceptual experience? Does what IBE tells us on this topic make it rational for us to rely on our perceptual experience in forming our beliefs about the external world? For reasons I explain in RS&EI, the answer is “no”.Footnote 35 I cannot repeat all of those reasons here, but I will respond briefly to some of what Lycan says to the contrary.
Lycan considers how SH and EDH compare in light of three theoretical virtues: conservatism, neatness, and testability. He says SH does far better than EDH when it comes to the theoretical virtue of conservatism (which is coherence with what we already believe).Footnote 36 However, recall that, as I noted in the previous paragraph, our task is to (i) compare the relative merits of SH and EDH as truth-indicative explanations of certain features of our perceptual experience and to (ii) do this while setting aside what we know via perception and what we know via epistemic intuition about the relative merits of SH and EDH. Thus, the proper way to appeal to the virtue of conservatism in this context is to consider whether SH or EDH coheres better with that part of what we already believe that does not include what we believe via perception and what we believe via epistemic intuition about the relative merits of SH and EDH. And SH does not cohere better (than does EDH) with that part of what we already believe. Lycan is right that SH coheres better (than does EDH) with the entirety of what we already believe (given that we believe SH and reject EDH). But, again, given that we are using IBE and appealing to the virtue of conservatism in order to accomplish tasks (i) and (ii) mentioned earlier in this paragraph, that is not what matters. We need to set aside some of what we already know so that we are not taking for granted the very things we are using IBE to determine—that is, the reliability of perception and the relative merits of EDH and SH.Footnote 37 Typically, we do not need to set aside so much when using IBE. But this is only because the hypotheses we are typically comparing all take for granted things like SH and the reliability of perception.
Lycan also says that SH does far better than EDH when it comes to the theoretical virtue of neatness (which amounts to raising fewer unanswered questions).Footnote 38 His remarks on this matter have persuaded me that I made a mistake in RS&EI when I briefly elaborated on EDH to address some unanswered questions about the deceiver’s motives and methods in deceiving me (Bergmann, Reference Bergmann2021, 49). As Lycan rightly points out, these questions could be answered in a million different ways. So why prefer the elaborations I suggested to any of the others? I now think it is better to stick with the more general version of EDH, according to which a powerful person has a strong desire to radically deceive me by arranging for me to believe that SH is true and getting me to have extremely misleading perceptual seemings. It is true that EDH, so understood, raises many unanswered questions (some of which, according to EDH itself, we cannot answer). But, as I note, SH also raises many unanswered questions (Bergmann, Reference Bergmann2021, 49–50).
Lycan says that EDH raises many more unanswered questions. To support this, he says (Lycan, Reference Lycan2024, 536), “we would indeed still have all the already unanswered questions about the physical and psychological worlds [i.e., the questions unanswered by SH], but in addition we would have a great mass of unanswerable new questions about” the deceiver mentioned in EDH. But it is not true that EDH raises all the questions raised by SH and more besides. A very large number of the questions that SH raises have to do with claims it makes about the physical and psychological worlds—claims that EDH does not make. So EDH does not raise, and its proponents need not address those questions.Footnote 39 It is true that EDH makes some similar claims insofar as EDH says that those claims SH makes appear to me to be true. However, those similar claims made by EDH are much easier to explain than the claims made by SH. In each case, the explanation EDH offers for its similar claims is the same, namely that the claims made by SH appear to me to be true because the deceiver wants me to (mistakenly) believe that SH is true.
The last theoretical virtue Lycan discusses (Reference Lycan2024, 537) is testability. He acknowledges that EDH predicts the same perceptual evidence that SH predicts, with the result that a focus on this virtue does not show that SH is better than EDH. But then he adds that we would have more positive reasons to think a deceiving demon is at work if, on occasion, the demon revealed his presence behind the scenes (peeking through the clouds at us briefly with a sardonic smile and a booming snide remark). It is true that this would provide a kind of “positive test result” in support of a different deceptive demon hypothesis—one where the demon is less competent at deception or more interested in getting credit as a deceiver than in successfully deceiving me. But as Lycan recognizes, this evidence or test result would count against EDH just as much as it counts against SH.
Lycan also complains (Reference Lycan2024, 537) that, despite being on a par in terms of testability (given that the same evidence confirms SH and EDH to the same degree), EDH is parasitic on SH, which makes it ad hoc. It is true that EDH is, in an important sense, parasitic on SH. But, as I pointed out in RS&EI, this does not make EDH a worse theory.Footnote 40 It is common in science for one theory to be parasitic on another, taking on board much of an already existing theory, while also altering it in some way to provide a competing theory that is equally good or better. This does not make the parasitic theory worse, nor does it make it ad hoc. In the case at hand, it helps us to see that EDH differs in important ways from SH while explaining all the same evidence just as well. Given that EDH says the deceiver intends to get me to endorse SH, it is no surprise that it is parasitic in this way on SH.
I will close with one last point, which I cannot develop at length. Suppose we look at the suffering and evil in the world along with the beauty and apparent design in nature, and we ask whether theism or atheism is a better explanation of all these things. It is common for theists to think that theism is a better explanation and for atheists to think atheism is a better explanation. As I see it, in thinking these things, both theists and atheists are often relying not on IBE but on other belief sources. These other sources incline them to hold their view about theism, which leads them to conclude that their view is a much better explanation. However, those who set aside these other belief sources and rely only on IBE (in a way suitable to the relevant dialectical context) often do not think their favored view is a much better explanation. Similarly, when commonsensists think that SH is a much better explanation than EDH of certain facts about our perceptual evidence, I suspect that they are relying not on IBE but on other belief sources, which incline them to endorse SH and reject EDH, leading them to think that SH is a much better explanation. But if they set aside these other belief sources and rely only on IBE (in a way suitable to the relevant dialectical context), they will not think that SH is a better explanation.
4. Steup
Let us turn finally to Steup. I will focus on four main topics from his comments: first, the dispute between particularism and methodism; second, two kinds of circularity; third, meta-justification; and fourth, the Problem of the Wheel.
Steup (Reference Steup2024, 540) says I endorse Chisholmian particularism. However, as I understand Steup’s definition of Chisholmian particularism—that is, as the view that “CE is true but EC is false” (Steup, Reference Steup2024, 543)—it is a view I explicitly reject. According to Steup, CE and EC are to be understood as follows:
EC: You can’t know the extent of knowledge unless you already know the criteria of knowledge.
CE: You can’t know the criteria of knowledge unless you already know the extent of knowledge.Footnote 41
And he shows how EC and CE can be used in an argument to obtain the skeptical conclusion that, as I understand it, says you cannot know any of the criteria for knowledge or any of the extent of knowledge. That argument seems to require that EC and CE should be understood more precisely as follows:
EC*: You can’t know any of the extent of knowledge unless you already know the full criteria of knowledge.
CE*: You can’t know any of the criteria of knowledge unless you already know the full extent of knowledge.Footnote 42
Thus, Chisholmian particularism, according to Steup, seems to involve endorsing CE* and rejecting EC*. But I make it clear in RS&EI that I reject both EC* and CE* (Bergmann, Reference Bergmann2021, 128–29). Following Tom Kelly, I distinguish hyper-particularism and hyper-methodism from more moderate versions of particularism and methodism.Footnote 43 And I emphasize two things about the kind of moderate particularism I endorse. First, it typically gives more weight to one’s particularist epistemic intuitions in support of epistemic evaluations of particular beliefs than to one’s methodist epistemic intuitions in support of epistemic principles (because the former intuitions are typically stronger than the latter). Second, it occasionally gives more weight to one’s methodist epistemic intuitions than to one’s particularist epistemic intuitions (because on occasion the methodist intuitions are stronger).Footnote 44 Steup later says things suggesting that he too rejects both hyper-particularism and hyper-methodism, so perhaps our views are not so different (at least in this respect).Footnote 45 In any case, Steup objects to what he thinks of as Chisholmian particularism, not to my version of particularism.
Let us turn next to the two kinds of circularity Steup discusses: epistemic circularity and source circularity. Here, it is important to avoid some potential confusion. Steup says that epistemic circularity is always bad, whereas I say that epistemic circularity is sometimes bad and sometimes not bad. And Steup adds that source circularity is sometimes bad and sometimes not. The problem with that summary is that in RS&EI, I use the term “epistemic circularity” to refer to what Steup calls “source circularity” (and Steup does not point out this difference in terminology, as far as I can tell). What I call “epistemic circularity” and Steup calls “source circularity” occurs when one relies on a belief source S in holding that S is a trustworthy belief source.Footnote 46 And, as noted, both Steup and I agree that there are both good and bad versions of such circularity. So far, Steup is offering no objection to my view.
A related point is that, in RS&EI, I do not explicitly discuss what Steup calls “epistemic circularity.” This is for two reasons. First, it is concerned with requirements for propositional justification, whereas my focus in RS&EI is on doxastic justification.Footnote 47 Second, it arises when higher-level requirements on justification are not satisfied; however, I deny that there are any such requirements on justification.Footnote 48
To see where Steup disagrees with me on the topic of his sort of epistemic circularity, we need to focus on a type of argument that Steup thinks is always bad and which I think need not always be bad. The form of this Controversial Argument Type is as follows:
The first premise asserts the content of some ordinary perception-based belief (e.g., this table is red, this is a zebra, I have two hands).
The second premise asserts that the content of the first premise entails the falsity of a skeptical alternative to that content (e.g., this table is white with red lights shining on it, this is a cleverly painted mule, I am a handless brain in a vat).
The conclusion asserts, on the basis of an inference from the two premises, the denial of the skeptical alternative in question.Footnote 49
I say several things about believing such conclusions based on such arguments. As Steup notes, I say that a belief so formed can be justified in J-permitting circumstances—that is, those in which I neither do nor epistemically should seriously question or doubt the trustworthiness of the belief source in question. But I also say four other things that Steup does not highlight. First, I say that such arguments are bad arguments if they are offered to those who are not in J-permitting circumstances (Bergmann, Reference Bergmann2021, 188). Second, I say that because a standard way to evaluate arguments is to consider whether they would be useful to those who doubt their conclusions (i.e., those who are not in J-permitting circumstances), arguments of the Controversial Argument Type will, by this reasonable standard, count as bad arguments.Footnote 50 Third, I say that this inferential way of arriving at the conclusion of this argument is atypical. We usually form such beliefs non-inferentially based on epistemic intuition (Bergmann, Reference Bergmann2021, 124). Fourth, given the previous three points, I emphasize that there are very few cases—that are even close to realistic—where forming beliefs via such arguments could reasonably be viewed as justified. They involve a person in J-permitting circumstances who:
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(a) justifiedly holds many ordinary perceptual, memory, and introspective beliefs;
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(b) has never before considered whether those beliefs are reliably formed;
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(c) comes to see certain implications of these beliefs—that is, implications according to which some of these ordinary beliefs are reliably formed and skeptical alternatives to them are mistaken;
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(d) upon seeing these implications, justifiedly believes these implications for the first time.Footnote 51
I take these remarks to accommodate the appeal of Steup’s intuitions that beliefs based on the Controversial Argument Type are always bad, while also explaining why such intuitions are mistaken.
Steup raises two main objections to my claim that it is possible for beliefs to be justified by reliance on the Controversial Argument Type. The first objection is that, in making this claim and defending it with examples, I am going against Steup’s Principle of Meta-Justification.Footnote 52 Obviously, this complaint assumes the truth of that principle, which I will discuss when I turn, next, to the topic of meta-justification. The second objection is that there are cases where one’s first-order belief is justified in part because one has higher-order evidence that one’s first-order evidence is reliable.Footnote 53 However, the existence of such cases does not count against my claim that it is possible for a first-order belief to be justified in the absence of such higher-order evidence.
Let us turn, then, to the topic of meta-justification—a topic on which Steup and I have significant disagreement. According to Steup’s Principle of Meta-Justification (Steup, Reference Steup2024, 540), a belief B is justified only if you have higher-order evidence that the evidence on which B is based is reliable. In order to avoid regress problems, he emphasizes (Steup, Reference Steup2024, 548) that you do not need to believe that the evidence on which B is based is reliable; all you need is evidence that it is. Why does Steup think this higher-order evidence is required for first-order justification? Here are two reasons he gives (Steup, Reference Steup2024, 541):
Reason 1: since our evidence for our beliefs often doesn’t entail their truth, “there is a skepticism-motivating evidential gap between our beliefs about the world and the way we perceptually experience the world. Meta-justification bridges this gap”.
Reason 2: “meta-justification puts you in a good position when the skeptic … asks you why you think a seeming that p is supposed to be a reason for believing p”.
In my view, these are not good reasons to endorse the Principle of Meta-Justification. Let me explain why.
What exactly does the Principle of Meta-Justification require? As noted above, it does not require believing that your first-order evidence is reliable, since that leads to regress problems. Presumably, it also does not require potentially believing this, since that too leads to regress problems, as does the requirement that you actually or potentially conceive of your first-order evidence as reliable.Footnote 54 This forces Steup to concede that one can have the required higher-order evidence that one’s first-order evidence is reliable even though one lacks even the potential to either believe that one’s first-order evidence is reliable or conceive of one’s first-order evidence as reliable. But then, contrary to what Reason 2 suggests, it is difficult to see how you will be in a good position to answer the skeptic who asks you why your first-order evidence that p provides you with a good reason for believing p . Likewise, contrary to Reason 1, it is hard to see how you have bridged the “skepticism-motivating evidential gap” if you have no story to tell about how you are helped by this evidence—no story that involves either your actually or potentially believing that your first-order evidence is reliable or your actually or potentially conceiving of your first-order evidence as reliable.
Finally, let us consider the Problem of the Wheel. As Steup presents the problem, it has to do with the trouble that arises if you endorse the following two claims, both of which he thinks are plausible and true, when properly interpreted:
JRp: Perception is a justification-source for you only if you have evidence that perception is reliable.
RJp: You have evidence that perception is reliable only if perception is a justification-source for you.Footnote 55
According to Steup, JRp conflicts with what he calls my “You Can’t Get Started” argument. Strictly speaking, that is not true, largely because I focus on doxastic justification rather than propositional justification.Footnote 56 Nevertheless, Steup is right to think that I will object to his defense of the joint truth of JRp and RJp. A key move in this defense of his is to interpret JRp and RJp synchronically rather than diachronically. He denies the diachronic claim that each of the things flanking the “only if” in JRp and in RJp must be had before the other; however, he affirms the synchronic claim that each of those things requires the other (Steup, Reference Steup2024, 548-549). As I understand him, the idea is that over time (from birth to some degree of conceptual maturity), you formed many beliefs via perception. At first, your perceptual beliefs did not have justification; as a result, you did not have evidence that perception is reliable. But eventually, two things happened at the very same moment: first, a significant number of your perceptual beliefs, for which you previously lacked justification, came to have justification via perception (their source); second, those perceptual beliefs (for which you now had justification) played a crucial role in your coming to have evidence for the reliability of perception. Neither the justification for your perceptual beliefs nor your evidence for the reliability of perception existed before the other, yet each required the other.
My main concern about this proposal is that it is like saying you can pull yourself into existence out of the swamp of nothingness, which is impossible.Footnote 57 Even if your coming into existence occurs at the very same time as your causing yourself to come into existence (so that neither is temporally prior to the other), each depends on the other, which makes the other metaphysically prior to it. Likewise, even if JRp and RJp are not speaking of temporal priority, they are speaking of dependence, where each of two things metaphysically depends on the other. According to JRp, perception cannot be a source of justification at t for any of your perceptual beliefs unless you have sufficient evidence for its reliability at t. And according to RJp, you cannot have sufficient evidence for the reliability of perception at t unless perception is a source of justification at t for at least some of your perceptual beliefs.Footnote 58 If X’s being a source of any amount of justification is metaphysically prior to your having any amount of evidence for X’s reliability and vice versa, then neither can occur.
Contrary to what Steup suggests, this is different from the coevolution of the clownfish and the anemone. In this biological evolution case, we have ancestors of the clownfish (C1-Cn) and ancestors of the anemone (A1-An). A1 has different features than its ancestor A2, which has different features than its ancestor A3, and so on. Something similar is the case for C1 and its ancestors. A1 depends for its existence on C1, which depends for its existence on A2, which depends for its existence on C2, which depends for its existence on A3, and so forth. In no case do we have strict mutual dependence, where both of the following are true: first, a thing X in the clownfish series could not come to exist with a set of features F1 unless there existed a thing Y in the anemone series with a set of features F2; and, second, that thing Y in the anemone series could not come to exist with a set of features F2 unless there existed that thing X in the clownfish series with a set of features F1. It could not be the case that both of these things metaphysically depend on the other for their first coming into existence with such features. They cannot each simultaneously pull the other into existence out of the swamp of nothingness.
Steup could alter his view to allow that a belief source can produce beliefs with some degree of justification, even in the absence of any evidence for its reliability. That small degree of justification from that source could perhaps be used somehow to provide some evidence for the reliability of that source, which could then produce beliefs with a greater degree of justification, leading to more evidence for that source’s reliability, and so on. (This view would fit better with his example of the coevolution of the clownfish and the anemone.) However, by altering his view in this way, Steup would be giving up on the strict mutual dependence of (i) perception being a source of justification for one’s beliefs and (ii) having evidence for the reliability of one’s perception on each other, in which case he would be giving up on his solution to the Problem of the Wheel, according to which JRp and RJp are jointly true.Footnote 59
Michael Bergmann is Professor of Philosophy at Purdue University. His main areas of research are epistemology and philosophy of religion. He is the author of Justification without Awareness (Oxford, 2006) and Radical Skepticism and Epistemic Intuition (Oxford, 2021), and he is co-editor of four volumes of essays, also published by Oxford University Press.