Knowledge-how, Understanding-why and Epistemic Luck: an Experimental Study

Two epistemic standings that are the topic of increasing interest in contemporary epistemology are knowledge-how and understanding-why.¹ There is an important point of connection between these two debates: each debate is marked by a divide between what we can call reductivism and non-reductivism, where the former camp insists that the epistemic standing in question is just a kind of propositional knowledge, and the latter camp denies this claim.²

In the case of knowledge-how, the central contemporary dividing line is between intellectualism and anti-intellectualism. Roughly, the distinction lies in the fact that the former, unlike the latter, holds that knowing how to do something is just a matter of knowing facts.³ Most contemporary intellectualists (e.g., Stanley and Williamson 2001; Stanley 2011a, b; Pavese (2015, 2017) regard knowledge-how to be itself just a special kind of knowledge-that.⁴ Anti-intellectualists, accordingly, deny that knowledge-how is a kind of propositional knowledge and thus attempt to show that various properties (linguistic,⁵ phenomenological,⁶ epistemic,⁷ cognitive-scientific,⁸ etc.,) of knowledge-how and knowledge-that can come apart.

Interestingly, there is a very similar and increasingly lively debate taking place in the arena of understanding. One central dividing line, at least amongst epistemologists, concerns whether understanding-why (e.g., as when one understands why the house burnt down) is just a special kind of propositional knowledge—viz., knowledge of (the relevant) causes.⁹ Traditional reductivists, following a precedent that owes originally to Aristotle, insist that it is. Non-reductivists (e.g., Pritchard 2009, 2014a; Pritchard, Millar & Haddock, chs. 1–4; Hills 2009; Morris 2012; Grimm 2014), take the opposing view and claim (for different reasons) that understanding-why and knowledge-that can come apart.¹⁰

There is, however, yet a further and more specific commonality between the two debates. This further point where the two debates parallel one another concerns a specific kind of epistemologically oriented argument strategy which has been deployed recently against reductivist proposals of both stripes. Put simply, the idea goes as follows: propositional knowledge (i.e., knowledge-that) is widely regarded by epistemologists to be incompatible with certain kinds of epistemic luck, as Gettier-style cases famously illustrate.¹¹ Hence if it turns out that knowledge-how and understanding-why differ from knowledge-that that in their respective compatibility with epistemic luck, then this looks like a serious problem for reductivists about knowledge-how and understanding-why, who are committed to predicting otherwise in virtue of regarding these epistemic standings as species of propositional knowledge.

That knowledge-how and understanding-why should (according to reductivist proposals) be compatible with epistemic luck to the same extent as knowledge-that is a point agreed on by critics as well as by defenders of these reductive views. Indeed, Jason Stanley (2011a, 215)—the foremost proponent of contemporary intellectualism about knowledge-how—explicitly recognizes this constraint as legitimate. He remarks that ‘[i]f knowing-how is a species of knowing-that, the properties of knowing-that should be properties of knowing-how’, where he concedes further that these includes purely epistemological properties, such as resilience to undermining epistemic luck.¹² It is hence no surprise that Stanley has attempted to defend his view against the charge that Gettier cases are more difficult to generate for knowledge-how than knowledge-that.¹³

Likewise, in the parallel case of understanding, non-reductivists—such as Kvanvig (2003; 2009), Pritchard (2009, 2014a), Pritchard et al. (2010, chs., 1–4), Morris (2012), and Rowher (2014)—have argued (in different ways) that understanding is compatible with at least some species of epistemic luck that are incompatible with knowledge-that.¹⁴ On this basis, they have claimed that understanding is not a species of knowledge-that.

Our overarching objective in the paper is to assess the extent to which philosophers’ as well as non-philosophers’ willingness to attribute knowledge-that, knowledge-how and understanding-why are in alignment with what these two reductive proposals are committed to, in particular with respect to the compatibility of epistemic luck with knowledge-how and understanding-why (respectively).

Accordingly, we tested whether the presence of epistemic luck impacts upon ascriptions of knowledge-that and knowledge-how equally across a range of luck (and corresponding control) vignettes.

Accordingly, we tested whether the presence epistemic luck impacts upon ascriptions of knowledge-that and understanding-why equally across a range of luck (and corresponding control) vignettes.

In addition to testing these two hypotheses, we wanted to test for a potential difference in knowledge and understanding ascriptions between participants with expertise in philosophy and (more specifically) in epistemology, and participants without this expertise. The idea for testing for this difference arose after initial pilot studies showed—along with literature that was emerging around the same time (e.g., Turri et al. 2015)—a surprising tendency for participants to attribute knowledge and understanding even in the presence of luck, at least in some circumstances. We hypothesized that greater training in philosophy, as well as greater training in epistemology, would correlate with an increased tendency to deny knowledge in cases involving luck.

Our experimental results revealed, in the main, an interesting disparity in judgments between those with self-reported philosophical training as opposed to those without. Those with no self-reported philosophical training don’t respond to the presence of epistemic luck (in comparison with control cases with no luck present) in a way that suggest that they hold that it undermines knowledge-how, understanding-why, or even knowledge-that.¹⁵ Accordingly, those with no self-reported philosophical training attribute knowledge, understanding-why and knowledge-how in a way that is broadly consistent with the hypotheses which both of the two reductivist accounts under consideration would predict, respectively.¹⁶ Surprisingly—and this is a point we’ll raise in more depth in the discussion section—one curious result was that those with no self-reported philosophical training were actually more likely to attribute knowledge-how in cases where luck was present than in the control cases where it was not. In sum, the results from those with no self-reported philosophical training did not align with what non-reductivists (including the present authors) about knowledge-how and understanding-why should expect.

However, things were very different in the case of those individuals with self-reported philosophical training. Such individuals attribute knowledge-that, understanding-why and knowledge-how in a way that runs contrary to what should be expected if either of the reductive proposals is correct. What we found was, in summary, that those with self-reported philosophical training regarded propositional knowledge to be more susceptible to being undermined by the presence of epistemic luck than did those without such self-reported training,¹⁷ whereas, by contrast, those with self-reported philosophical training regarded knowledge-how and understanding-why to be less susceptible to being undermined by the presence of epistemic luck than those without self-reported philosophical training.

More specifically, with regard to knowledge-how and knowledge-that: we found that those with self-reported philosophical training, as well as self-reported training in epistemology in particular, were inclined to regard knowledge-that as more susceptible to being undermined by the presence of epistemic luck than were those without such self-reported training. Regarding understanding-why and knowledge-that: those with self-reported philosophical training were inclined to judge knowledge-that as more susceptible to being undermined by epistemic luck than those without such self-reported training, and further to judge understanding-why as comparatively more compatible with it. However, and this is a point we’ll address in the discussion section, those with self-reported high epistemological training, specifically, took the opposite line vis-à-vis understanding-why.

We should note that, given that two of the authors (e.g., Carter and Pritchard 2015a, b, c) have defended non-reductivist accounts of both knowledge-how and understanding-why elsewhere, we were expecting that the experimental results would on the whole not vindicate Hypothesis 1 and Hypothesis 2¹⁸; and if Hypothesis 1 and 2 were not borne out by the experiments, then this would have been welcome news to the non-reductivist. We take the results of our experiments to be, in sum, an interesting mixture of bad news (i.e., the data from participants without self-reported expertise) and good news (i.e., the data from participants with self-reported philosophical expertise) from the perspective of the non-reductivist. The matter of just how good (or bad) the news was, taken together, for the non-reductivist about knowledge-how and understanding turns out to depend on a range of considerations to do with metaphilosophy and philosophical methodology, which we discuss in detail in §4.

Here is the plan. In §§2–3 in we report and interpret our experimental procedures and results. In §4, we offer a critical discussion which contextualizes these findings by showing how one very natural interpretation of our results fits very well with a ‘cognitive achievement’ model of knowledge-how and understanding-why. We conclude by situating the interpretive narrative advanced within contemporary discussions about the role of expertise in philosophical judgment.

The nub of the matter is that those without self-reported philosophical training are much more inclined to attribute knowledge-that, knowledge-how and understanding-why in patterns that are consistent with Hypothesis 1 and Hypothesis 2 (predicted by the two reductivist proposals), than are those with self-reported philosophical training. That said, we submit that there is a further, positive element of this narrative. This positive angle is that those with self-reported philosophical training not only attributed these standings in a way that runs contrary to what the reductive proposals predict, but also the pattern of attributions by those with self-reported philosophical training aligns very well (and much better than does the pattern of attributions by those without self-reported philosophical training) with a certain principled way of thinking about cognitive achievement, which is (in short) cognitive success that is primarily because of cognitive ability.

Before we get to this point about cognitive achievement, however, we will first explore two kinds of ‘outlier’ results that seem to run contrary to this narrative, and what might account for them. As we have noted, those with no self-reported philosophical training don’t really think that the presence of epistemic luck (in comparison with control cases with no luck present) undermines knowledge-how, understanding-why or even knowledge-that. However, in the case of knowledge-how specifically, both those with no philosophical training as well as with self-reported philosophical training actually moved in what is (from an epistemological standpoint) an almost inexplicable direction: they were more likely to attribute knowledge-how in cases where epistemic luck is present than in the control cases where no luck was present. This is obviously very surprising. We have two remarks to make on this point, one specific, the other more general.

The first remark is that, at least, from an epistemological perspective, it’s hard to make sense of how the presence of luck could generate any kind of epistemic gain of any sort. However, there might be a non-epistemic story to tell. For example, Martha Nussbaum’s (1986) treatise on moral luck maintains that certain kinds of moral value are importantly tied to human vulnerability. One way to think of this point is in terms of the goodness of a life narrative: a life narrative that includes fortune in the face of vulnerability is perhaps (in terms of moral value) to be desired to one without it.²⁵ At any rate, if the thought that success in the face of vulnerability brings about a special kind of value, the precedent for thinking so is likely moral rather than epistemic.

A second more general point is this. After reading our vignettes, participants were asked about both knowledge-how and knowledge-that. It is possible that being asked about both generated an inclination to offer contrastive ratings. One way this might have gone is as follows: In the non-lucky condition, participant attention may have been focused upon the propositional nature of the information delivered—upon the fact that knowledge-how was transmitted via written instructions—rendering an ascription of knowledge-that (i.e., propositional knowledge) seemingly more apt by comparison than an ascription of knowledge-how. In response, participants may have rated knowledge-how lower simply as a way to contrast knowledge-how with knowledge-that. This might explain the fact that ascriptions of knowledge-how are lower in degree, even though they are far enough above the mid-point to qualify as ascriptions of knowledge-how overall. By contrast, in the lucky condition, the presence of luck may have impacted ratings of knowledge-that significantly enough to erase this contrastive effect (indeed, high-training participants showed an effect in the opposite direction, rating knowledge-that lower than knowledge-how (M = 4.4 vs. 5.2, respectively). If this proposal is correct, further studies asking about only knowledge-how or knowledge-that, as opposed to both, should erase this odd result.

The second kind of ‘outlier’ case with respect to the more general trend of results we found concerned a subset of those with self-reported philosophical training—specifically, those with self-reported high degrees of epistemological training—who regarded not only knowledge-that to be incompatible with epistemic luck but also took understanding-why to be incompatible with epistemic luck. We think there is potentially a natural explanation for this. This involves noting a disparity between what has been the received view within epistemology, specifically. Consider that ‘anti-reductivism’ (in the form of anti-intellectualism) has been the received thinking about knowledge-how within epistemology since Ryle (1945, 1949). In contrast, it’s only been relatively recently that the position that knowledge-how is a kind of knowledge-that has been submitted as a serious position in epistemology. This is not the case for understanding-why. As Stephen Grimm (2014, 329) has remarked, the view that understanding is just knowledge of causes is in fact ‘the traditional view of understanding’—one with ‘longstanding appeal.’²⁶ It would thus not be surprising that individuals with not just philosophical training, but specifically epistemological training, might be more inclined to judge in accordance with the inherited view, due to exposure. This might potentially explain why the fine-grained class of individuals with self-reported philosophical training who reported high degrees of epistemological training would be more inclined to think of understanding-why as (like knowledge-that) incompatible with epistemic luck, even though this intuition wasn’t present with regard to knowledge-how.²⁷

We want to shift focus now to an interesting aspect of the results from individuals with self-reported philosophical training. Regarding this shift, one caveat deserves mention. The analyses we performed were exploratory, and conducted in response to surprising pilot studies that indicated non-philosophers attributed knowledge and understanding in the presence of luck. Before running the studies with expert participants we had a weak expectation that we would find differences between philosophical and epistemological ‘experts’ and ‘novices.’ But we needed to run the studies and analyses to make sure. As a referee notes, such exploration is epistemically permissible and necessary, but given the fuzziness of our priors before conducting the analyses, replication would bolster confidence in the conclusions we wish to draw. However, given difficulties associated with accumulating high numbers of those with high philosophical training, it outstrips our capacities to replicate these results with higher numbers of participants (but see Horvath and Wiegmann 2016). We leave it, then, to future work to perform the necessary replications regarding the differences we have reported.

As we noted, individuals with self-reported high philosophical training think to a greater extent than those without self-reported training that (i) propositional knowledge is incompatible with epistemic luck, whereas by contrast (ii) knowledge-how and understanding-why are held to be compatible with it. As we noted, this pattern of attributing these epistemic states runs contrary to Hypotheses 1 and 2 as predicted by reductive intellectualism and traditional reductivism about understanding-why, respectively.

Interestingly, however, this pattern of attributions fits very well overall (albeit not perfectly)²⁸ with a certain strand in the contemporary literature, regarding the nature of cognitive achievement.²⁹ Cognitive achievements are held to be cognitive successes—true belief, typically—which are primarily attributable to one’s exercise of relevant cognitive agency. So, for example, it is not enough for a cognitive achievement that one gets it right (i.e., one is cognitively successful), since this could be attained by pure happenstance (a lucky guess, say). In particular, one’s cognitive success needs to be the product of one’s cognitive ability, as when one uses one’s observational skills to form a belief about one’s environment. But even cognitive success that is the product of (relevant) cognitive ability is not sufficient for cognitive achievement, as one’s cognitive success can always be Gettierised. Perhaps, for example, one skillfully forms an observational belief about one’s environment, but that this belief is only true due to happenstance (as in the famous case of the farmer who skillfully, and truly, judges that there is a sheep in the field, albeit by looking at a big hairy dog which is obscuring from view the sheep behind). In this case one’s cognitive success, while in a purely causal sense a product of one’s cognitive ability, is not attributable to one’s cognitive ability, but rather simply down to luck. Cognitive achievement thus demands a certain kind of explanatory relationship between one’s cognitive success and one’s cognitive agency, whereby the former is primarily attributable to the latter (as opposed to other factors, such as dumb luck).

A further distinction that we can draw here is between strong and weak cognitive achievements. Whereas the latter only requires a cognitive success that is primarily attributable to one’s exercise of relevant cognitive ability, the former requires more. In particular, it demands that one’s cognitive success either involves the manifestation of a high level of cognitive ability, or else that it involves the overcoming of a significant epistemic obstacle to success. The point of the distinction is to highlight that weak cognitive achievements are sometimes very easily attained. Indeed, in normal circumstances, one can exhibit a weak cognitive achievement just by opening one’s eyes and observing one’s surroundings. Strong cognitive achievements, in contrast, are less common. For example, in virtue of his superior cognitive skills, Sherlock Holmes may observe something in one’s environment that one would never spot by oneself. Or consider the person who works out the mathematical puzzle herself, rather than simply looking up the answer at the back of the book. In doing so she has overcome an epistemic obstacle to success and thereby exhibiting a strong, rather than just a weak, cognitive achievement.³⁰

The relevance of cognitive achievements for our purposes becomes apparent once one reflects that while cognitive achievements are incompatible with standard Gettier-style epistemic luck (which undermines knowledge-that), they are compatible with another kind of epistemic luck, a species of epistemic luck which is incompatible with knowledge-that. Standard Gettier-style epistemic luck is intervening epistemic luck, in that it involves an external factor intervening between the success and the subject’s cognitive agency such that the former is not primarily attributable to the latter.³¹ So, for example, in the famous case offered above of the farmer’s belief about there being a sheep in the field, he isn’t actually looking at a sheep at all, but only a sheep-shaped object. Nonetheless, despite this disconnect between what he thinks he is looking at and what he is in fact looking at, his belief happens to be true regardless.

Not all epistemic luck which undermines knowledge-that is of this intervening sort, however. Consider environmental epistemic luck, which is the particular variety of epistemic luck which featured in each of our ‘luck’ vignettes. This is where nothing intervenes between the subject’s cognitive success and her exercise of cognitive agency, but where nonetheless the belief so formed is only luckily true on account of some feature in the subject’s environment. Suppose, for example, that our farmer really is looking at a genuine sheep rather than a big hairy dog, but that it is in the nature of his environment that he could so very easily have been looking at a big hairy dog instead and would have been none the wiser. So construed, although there is no intervening epistemic luck in play, it is nonetheless the case that his true belief could very easily have been false, just as in the standard Gettier-style case involving intervening epistemic luck. That’s why the prevailing orthodoxy in mainstream epistemology has been to judge that knowledge-that is lacking in such cases. Crucially, however, cognitive achievements seem to be compatible with environmental epistemic luck. After all, although our farmer could so very easily have been mistaken, given the actual circumstances he is in his cognitive success does seem to be primarily attributable to his exercise of cognitive agency. Remember that he really is seeing a genuine sheep before him, and his true belief is attributable to precisely this exercise of his cognitive agency.³²

Cognitive achievements thus come apart from knowledge-that, albeit in subtle ways.³³ Moreover, it has been argued in the literature that knowledge-how and understanding-why are similarly compatible with environmental epistemic luck.³⁴ Indeed, it has been proposed that the reason for this is that these epistemic standings are both kinds of cognitive achievement, unlike knowledge-that.³⁵ If this point is correct, then one initially tempting conclusion to draw is that the model of cognitive achievements articulated in the foregoing (in some sense to be clarified) gains pro tanto support from our experimental results in the following very specific respect: that those with self-reported philosophical training were considerably more inclined than those without such training to attribute knowledge-how, understanding-why and knowledge-that in patterns that are consistent with this model of cognitive achievements.

This (tentative) explanation suggests a direction for future research. One key question that has emerged concerns the susceptibility of expert and novice philosophical judgments to the model of cognitive achievements sketched above. Future studies could operationalize this model via a series of cases, and test the judgments of novices and experts regarding knowledge-that on the one hand, and cognitive achievements of different sorts on the other hand. Results in line with those we report here would serve as a conceptual replication in favor of our explanation. But in any case results from such studies would serve as an interesting extension of experimental work that seeks to understand the sensitivity of attributions of epistemically interesting concepts to types of luck.

Here, though, it is important to be careful. Consider that any thoroughgoing validation story ought to be prepared to indicate why it would be ‘better news’ for a given view that those with self-reported philosophical training attribute epistemic states in a way that is compatible with the view than do those without such training. And on this point some delicacy is needed because there are in fact two very different ways such a claim might be put forward. One strong way of advancing this further claim, we suggest, runs in to the well known ‘calibration problem’ for philosophical expertise, while a weaker way of advancing the further claim plausibly avoids it.³⁶

The strong and comparatively less defensible interpretation of the claim in question is that, generally speaking, intuitions informed by philosophical training are more truth-conducive than are non-philosophical intuitions (e.g., Williamson 2007, 2011). This appeal to philosophical expertise, as part of a general claim about intuitions, is notoriously problematic to defend.³⁷ Part of the difficulty here is that whereas other epistemic sources, such as perceptual observation, can be calibrated for their reliability by comparing their results against results gained from other sources, this kind of calibration doesn’t seem to be available in the case of philosophical intuition, since this seems only to be testable by appeal to other philosophical intuitions.³⁸

However, there is plausibly a weaker but also interesting version of this kind of claim available, and one which needn’t take for granted any contestable general thesis about the truth-conduciveness of philosophical versus lay judgments. The weaker version of the claim takes as a starting point the observation that the explanation (on the cognitive achievement model articulated above) for why knowledge-how and understanding-why are compatible with a kind of epistemic luck that’s incompatible with knowledge-that is a philosophically nuanced one, one the detection of which would plausibly be more likely for those with practice and training in philosophy than for those without it. If this claim about nuance and detection is on the right track, then given that, as Williamson (2007, 191) puts it, ‘philosophy students have to learn how to apply general concepts to specific examples with careful attention to the relevant subtleties …’, we’d have reason to expect that a potential explanation for why (in short) lay versus trained judgments came apart is that the nuances were detected to a greater extent by the judgments of those with training as opposed to those without training.

One initial counter to the weaker interpretation is that those with philosophical (or, at least, epistemological) training might not actually be detecting nuance at all but rather reflecting what is perhaps a dogmatic tendency in undergraduate epistemology classes to teach that know-how is ‘ability knowledge’. Perhaps, as this line of thinking might go, if know-how were not so quickly set aside as something other than propositional knowledge in the course of epistemology undergraduate education, those with such training might be more inclined to view these cases without prejudice.³⁹ While this is an interesting point, we submit that it would be problematic to conclude that, even if this prejudice were a pervasive one, it would better explain the patterns of judgments by those with self-reported training than detection of nuance, given that (i) any such prejudice would not directly involve assessments of know-how and luck (given that the claim that know-how is ability knowledge is not a claim about luck); and (ii) given that the capacity to detect the relevant nuances (i.e., the kinds of capacities acquired through thinking carefully about Gettier cases in epistemology classes) bears directly on how such individuals would assess the relevant cases. Furthermore, the judgments reported by those with training indicate parallel inclinations in the case of understanding, where such a prejudice would not similarly apply.

A second challenge to this weaker interpretation is that we’d need some evidence that the cases are in fact nuanced enough that their subtleties would be picked up to a greater extent by those with philosophical training than otherwise. Interestingly, there already is some, albeit indirect, evidence to this effect. In a 2013 study, John Turri (2013) reported experimental results which indicated that ‘laypeople who answer that the Gettier subject knows aren’t competently enough assessing the case.’⁴⁰ To the extent that this is right, we have some cause to doubt that those without philosophical training would be as sensitive by comparison as those with such training at picking up nuances at least as sophisticated as the Gettier intuition.

We say ‘at least’ because, as Turri et al. (2015) have reported in a recent paper, participants’ willingness to attribute knowledge is plausibly also sensitive to a fine-grained distinction among lucky event types; in particular, Turri et al. (2015) found that knowledge attributions are comparatively more insensitive to luck that threatens, but ultimately does not change (as in the specifically environmental luck which featured in our luck cases does not), the explanation for why a belief is true in contrast with lucky events which do change the explanation for why a belief is true. Psychological or other explanations⁴¹ for why this is so pose, as they note, an ‘important question for further research’ (2015, 388) and we agree, particularly because (at least with reference to the epistemological notion of safety (e.g., Pritchard 2005)) the relative unsafety of a target belief can be fixed across cases pairs that differ with respect to the role luck plays in explaining why an individual’s belief is true.⁴² At any rate, given that our luck cases were uniformly environmental and as such cases where the luckiness did not change the explanation for why the target belief is true, we have some additional reason to doubt that those without philosophical training would be as competent by comparison as those with such training at assessing the case pairs in light of the presence of luck.

As we’ve reported, patterns of judgment according to which knowledge-how and understanding-why are compatible with a kind of epistemic luck that’s incompatible with knowledge-that align to a greater extent with those with self-reported philosophical than with those without it. This—as well as the overarching cognitive achievement line outlined in this section—stands compatible with the datum that those with self-reported philosophical expertise do in fact attribute knowledge-that to some extent in environmental luck cases, a datum that was also reported in a recent study by Horvath and Wiegmann (2016).⁴³

To be clear, our positive narrative advanced in this section, as a candidate way of making sense of the patterns of attribution of knowledge-that, knowledge-how and understanding by those with self-reported philosophical training, is compatible with recognising this much while at the same time highlighting the comparative differences on this score between the judgments of those with and without philosophical training and what these differences might indicate. It is also not meant to rule out the possibility of other reasonable explanations of the data.

More generally, we’ve highlighted the cognitive achievement narrative as at least a potential interesting explanation for how the experimental results reported by those with self-reported philosophical expertise, beyond just that they do not fit well (as the results from those with no self-reported philosophical training do) with reductivist accounts of knowledge-how and understanding-why. In this respect, we see how the results reported by those with philosophical training might also but lend some credibility to a certain kind of rival account of contemporary interest. This positive point, we think, is best appreciated however not against the backdrop of any particular substantive way of thinking about the comparative evidential weight of philosophical intuitions versus folk intuitions, but rather more modestly alongside J. L. Austin’s (1956) point that while ordinary language can lay claim to being the first word, it cannot lay claim to being the last.

We want to conclude this section by noting how our results interface with results on understanding and luck reported in interesting recent work by Wilkenfeld et al. (Forthcoming).⁴⁴ The objective of this work was, in the main, to adjudicate experimentally a dispute between Kvanvig (2003) and Grimm (2006) about whether luck cases show that understanding-why and knowledge-that come apart.⁴⁵ In particular, their position can be summarised as follows: ‘Kvanvig is right that attributions of understanding are relatively insensitive to luck (more specifically, to what we and others call “environmental luck”), but Grimm is right that attributions of understanding are no less sensitive to luck than attributions of knowledge.’⁴⁶ (Wilkenfeld et al. forthcoming, 5) Our results largely comport with these findings in the specific case of folk attributions of understanding-why and propositional knowledge; those with little to no self-reported philosophical training were inclined to attribute not only understanding-why in the presence of environmental epistemic luck but also knowledge-that; however, our results caution against broader conclusions Wilkenfeld et al seem inclined to draw on the basis of the folk attributions reported. They write:

Given that expert patterns of attribution in fact differ importantly from folk patterns of attribution in a way that is relevant to whether understanding-why should be treated as a variety of propositional knowledge, we should at minimum address an interim epistemological problem before drawing as Wilkenfeld et al do the conclusion that we would do well to treat understanding and knowledge as roughly of a kind. And that interim epistemological problem would involve in some principled way adjudicating between the evidential weight of what we see are competing patterns (between experts and folk) of attribution that militate in different directions on the question of whether understanding-why and knowledge-that come apart. Such a problem, as we’ve noted in this section, is unavoidably tied to the deep and difficult issues canvassed concerning the viability of (and criticisms of) the expertise reply.⁴⁷