Long after originally devoting at least some thought to the topic, I have decided finally to write up some of what puzzles or concerns me about the treatment of knowledge (by perception or hearsay) as an exercise of a rational capacity, and especially about the treatment of error, in Quellen des Wissens. Which I still have not read all of, the fourth part remaining outstanding, and since the ninth chapter (the first of the fourth part) contains sections titled "Das Ideal der Fähigkeit" and "Formen des Scheiterns, Tadel und Entschuldigung", it is hardly impossible that it will contain material relevant to what is bugging me. But (a) these things really should have been addressed in the third part, which (moreover) gives no indication that a more in-depth treatment is still to come, and (b) when I took up the book again to finally actually make some headway in the fourth part I was reminded of several of the things that bothered me about the third, and it's in order to actually get those thoughts out, so that I can move on to the fourth part in earnest, that I'm writing this now. Let me say also, by way of increasing the length of this prologue, that I found (am finding) the book really engaging and interesting, and very much worthwhile.
The basic move of the third part of the book, stated perhaps more crudely than is possible, is to conceive of belief-formation as the exercise of a rational capacity for gaining knowledge via, e.g., perception (hence the book's mouthful of a subtitle, Zum Begriff vernünftiger Erkenntnisfähigkeiten), where the capacity in question is to be construed along the lines of an Aristotelian dynamis as laid out in Metaphysics θ to which, correspondingly, some exegetical attention is given. This is supposed to establish an explanatory asymmetry in which success (= actually knowing) is explained directly with reference to the operation of the capacity, while failure (= merely believing) is explained with reference to the capacity's being inhibited by some particular state of affairs which has interfered with its operation—"by denial and removal", as Aristotle puts it. (As will be seen, though, it's not very clear whether Kern thinks the failure of the exercise of a capacity, or the absence of a capacity, is to be explained in this fashion.)
The following passage initially excited my concern:
Die Überzeugungen, die jemand, der im Dorf der Scheunen-Fassaden vor der einzig echten Scheune bildet, ist zufällig wahr, weil die Scheunen in diesem Dorf im paradigmatischen Fall derart sind, daß jemand, der einen sinnlichen Eindruck von einer Scheune hat, kraft dieses Eindrucks nicht in der Lage ist, zu einer wahren Überzeugung zu kommen. Der paradigmatische Fall eines sinnlichen Eindrucks einer Scheune ist im Dorf der Scheunen-Fassaden kein Fall der Aktualisierung einer vernünftigen Erkenntnisfähigkeit. Das aber heißt nicht anderes, als daß man im Dorf der Scheunen-Fassaden nicht die Fähigkeit hat, durch sinnliche Eindrücke die Scheunen in diesem Dorf zu erkennen. (p 272; emphasis added)
One could be concerned about the "paradigmatic case" stuff, which, as near as I can recall, crops up in this passage for the first time; for one thing, we have been given no reason why we're interested in what is paradigmatically the case in this village rather than what is paradigmatically the case in this state (in this county, in this country, when standing before this barn). Which is not irrelevant to the concern I had about the highlighted clause: namely, that explanation of error by reference to one's not having the capacity in this case is different from explanation of error by reference to one's capacity being fallible or exercised wrongly, or the like. And while it does, admittedly, seem plausible to say that in barn-facade country one doesn't have the capacity to know via glancing whether one is before a barn; one doesn't have that sort of discriminatory capacity. But if that's true it seems to be because one doesn't have, in general, the capacity to discriminate between barns and cunning barn facades, if one is just driving past them, anyway; and one could always say, of any other perceptual error, that of course one didn't have the discriminatory capacity that would have led one not to commit the error—because, obviously, otherwise one would not have committed it. This style of explanation is particularly unsatisfactory here because it looks to assimilate rational capacities (which produce "contrary effects") to nonrational capacities—as in fact seems to be the case in the chapter on satisfactory and unsatisfactory circumstances.
I want to pursue a slightly more organized course here than usual, though, and that stuff will actually comes somewhat more in the middle, basically marching through Kern's use of Aristotle in the order of the Aristotelian text. So here are some questions from that direction one might have: (a) Metaphysics θ 2–5 are, officially, concerned with dynameis kata kinesis; perception is not a kinesis but an energeia, so how much of this discussion can we apply to a discussion of the capacity to perceive? (b) How are we to understand the relation to, and especially production of, contraries in the case of the capacity to perceive? (c) How are we to understand the role of "desire or choice" (Kern has "desire in the sense of choice") when it comes to the capacity for perception? (d) How are we to understand the claim "it has the potentiality in question when the passive object is present and is in a certain state; if not it will not be able to act" (1048a15–16) in this context?
Obviously these and related questions can be and have been asked just about Aristotle, nevermind Kern's use of Aristotle. I am not even going to attempt to address (a) except insofar as it impinges on (b), though it's a general sort of theme, and for the rest I'm just going to briefly state concerns. (Kern doesn't address (a) at all; I'm not sure focusing on belief-formation on the basis of a perception nullifies its relevance, but in any case, it just doesn't come up.) Kern's discussion of (b) seems to run the relation to and production of contraries together with the questions of deciding and of the having of a capacity as that figure in (c) and (d) (see pp 226–230), which is very unhelpful; in any case, what she says about the relation to contraries involves the explanatory asymmetry noted above: "Denn Aristoteles begründet die Behauptung, daß vernünftige [= besouled] Fähigkeiten einen Bezug auf das ihnen Gegenteilge haben, damit, daß ihr logos sowohl die »Sache« wie auch den ihr gegenteiligen Fall, den er als »Privation« bestimmt, erklärt" (p 225). The capacities explain two different classes of events, and for some of them they offer "eine Erklärung »durch Verneinung und Wegnahme« von etwas, das zur Fähigkeit gehört. Beispiele für solch negativen Fälle sind etwa der Skifahrer, der beim Drehschwung stürzt; der Lesende, der sich verliest … und schließlich der Arzt, der seinen Patienten nicht gesund macht, sondern mit einem raffinierten Giftbrei um die Ecke bringt" (p 227). I believe that later (or … earlier; anyway, somewhere) she makes the claim that the capacity explains the contrary also in this sense, that if there were no such thing as reading there would not be misreading; absent skiing, in general, no such thing as a poorly executed Drehschwung, whatever that may be. And in that respect, too, one might explain the talk of rational capacities producing contraries, in that (how convenient that Aristotle's frequent use of doctoring as an example allows for this pun) malpractice depends on practice for its possibility. But that general sort of characterization won't explain this particular doctor's malpractice, here and now, and that's the kind of example Aristotle gives.
Kern's discussion here moves quickly to decision, a topic first broached in Aristotle in chapter five; but it is probably worthwhile to stick with chapter two for a bit. Kern omits, when giving translations from Aristotle from ch. 2, both mention of the fact that there rational capacities are said to produce, not merely explain or be related to, contrary effects, and the claim in the chapter's second sentence that "all arts, i.e. all productive forms of knowledge [technai and poietikai epistemai], are potentialities"; in these cases, I think, it's much easier to see how (or see a way how) both the relation to and the production of contraries could work. Heidegger, for instance, has a pretty interesting account here (one is always a bit uncertain how far to trust Heidegger when it comes to interpreting Greek philosophy, but the account is interesting, and Kern cites him (specifically Aristoteles' Metaphysik θ 1–3: von Wesen und Wirklichkeit der Kraft, which is what I'm using (in translation) too) for support, so I think he's fair game). Although Heidegger translates the relevant passage as "all skills and ways of versatile understanding in the production of something are forces (thus capability in our sense)", that is, in a way that leaves open the possibility that things other than technai are dynameis kata kinesis, he later he identifies them, saying things like "the technai are the dynameis kata kinesis" (rather than "the technai are dynameis kata kinesis"). At any rate, he gives skills and production pride of place when talking about the production of contraries. The ensuing discussion is rather involved, but one way to understand the both the relation to, and the production of, contraries, when we are thinking primarily of end-directed processes that are not complete at every moment (which bring something into existence), and especially when we are thinking of technai, is that "as the material and each particular state in the course of production offer occasions for mistakes and failure and for being irregular … logos … is constantly what excludes, but this means that it includes the contrary with it" (pp 121f); the producer is concerned with an end that sets a standard for what he is doing and insofar as he is taking care to do that is referred to the various things that would trip him up or spell failure or the like. And just this process will occasionally lead to the production of the contrary.
(I just noticed something odd: towards the end of this discussion Heidegger writes "Every production of something, in general every dynamis meta logou, prepares for itself, and this necessarily, through its proper way of proceeding, the continually concomitant opportunity for mistaking, neglecting, overlooking, and failing" (p 131), but in both the previous and the next section he speaks in a way that makes it seem as if he's still focused on dynameis kata kinesis, thus (apparently) not every dynamis meta logou, or, if every, in a way that is still unclear, given what has preceded.)
Kern avails herself, I think, of basically this kind of thought when it comes to explaining the production of contraries, though it's confusingly bound up with talk of decision, as if she is explicating chapter five rather than chapter two. Thus she gives this example: "»Weshalb ist Jim gestürzt?« »Weil er bei der Schwungsteuerung den Innenski belastet hat.«" (p 228); that is, Jim overlooked, failed to take account of, something that his end of skiing, and executing some particular move, called on him to do. And when talking about decision, she emphasizes that Aristotle must understand prohairesis "als eine überlegte Entscheidung dazu, das unter den gegebenen Umständen gemäß der Fähigkeit Richtige zu tun" (p 234) (citing here McDowell and Heidegger). What interests her about this is the claim that the ability to make this kind of considered decision is not independent of the having of the ability to exercise the capability, or rather, the ability to make such a decision is a further exercise of the capability, but it is not hard to see it as also akin to the point Heidegger wants to make, that in acting one is guided by one's understanding of what is to be done, given that one has the production of such-and-such as one's goal. Plausibly, being able to understandingly carry that deliberational task out (should the issue of actually deliberating arise) is not separable from being able to carry the actual task out, at least in a preliminary fashion.
It is, however, not at all clear to me how this applies to non-productive (non-kinetic, one might say) capacities. It's not just that one doesn't often make decisions about what to understand someone to mean, or to take someone's noisy productions as meaningful speech (though one sometimes does something like that, certainly: for instance, when listening to someone speak an unknown, unplaceable language, one may remind oneself that it is meaningful speech, though such a reminder doesn't enable one to take it as meaningful speech in the way that one takes the speech of someone who speaks a language one understands as meaningful); Kern is right to emphasize that we needn't be concerned with an explicit episode of coming to a decision. But it's hard to see how to get from her characterization of decision to something that does apply to such examples; and, even if we had such a path, we would still want to know where the room for the production of contraries came in. Thus towards the end of her exposition of Aristotle, she writes (now we are on (c)):
Wenn jemand in verständlichen Worten mit mir spricht, dann steht es mir nicht frei, ihn so oder anders oder gar nichts zu verstehen. Da hat Kenny ganz recht. … [Aristoteles kann] Akte als Aktualisierungen einer vernünftigen Fähigkeit zulassen, die nicht selbst das Resultat einer Entscheidung sind, sofern sie nur solche sind, zu denen sich das Subjekt dieser Akte entscheidend verhalten kann. … Wenn die grundlegende Bestimmung eines vernünftigen Aktes die ist, daß er einer vernünftigen Fähigkeit entspringt, dann verlangt dies nur, daß ein Akt, um vernünftig zu sein, einen Grund haben muß, den das Subjekt in Form eines Überlegens rekonstruieren kann und zu dem es sich entscheidend verhalten kann. (pp 236f, emphasis in original)
But the rejoinder to Kenny simply seems confused. Kenny's objection, as Kern recapitulates it, isn't that on a given occasion one doesn't need to decide or deliberate whether or how to understand someones understandable words; it is that it isn't up to one at all. So the doubtless correct claim that Aristotle can admit acts that aren't the result of a decision as long as they are such that the subject could have come to the acts from a decision, seems quite beside the point; Kenny's claim is that that is precisely what the subject cannot do. It's not just that the subject is especially practiced at understanding comprehensible English (etc.) words, but could reconstruct how he does it in syllogistic form for you if it for some reason came up; any such reconstruction would be foreign to the subject and not something on which he could act. (That this should be so is vital to Kern's broader epistemological strategy.) And consequently it is hard to see how to take account of what happens when I mishear except by citing environmental factors that would lead us to say that I don't have (in these circumstances) the capacity after all. But if we're going to talk about perception as a rational capacity, we need the capacity to produce contraries, not just to be subject to the proviso that it is only the capacity to … in certain circumstances. Which brings us to (d).
Here is the Aristotelian text:
Therefore everything which has a rational potentiality, when it desires that for which it has a potentiality and in the circumstances in which it has it, must do this. And it has the potentiality in question when the passive object is present and is in a certain state; if not it will not be able to act. To add the qualification "if nothing external prevents it" is not further necessary; for it has the potentiality in so far as this is a potentiality of acting, and it is this not in all circumstances but on certain conditions, among which will be the exclusion of external hindrances; for these are barred by some of the positive qualifications. (1048a13–20)
First, somethings that can be state briefly. As this translation has it, at least, the statement about external prevention concerns things which have rational capacities; that is the referent of "it" in "And it has the potentiality …". Kern, as seemingly everyone in her circle does (and as does Jon Moline in "Provided Nothing External Interferes" from 1975), applies this account indifferently to the dispositions of the soulless and to the capacities of the besouled.
I think the following is also fair: it would strain belief to attribute my making a mistake in the execution of some task always to some external hindrance; sometimes a loud noise distracts me and I don't finish the task, or sometimes a bomb destroys me and I don't finish the task, and those are external hindrances, but sometimes I just slip up, and it's hard to see why that is an external hindrance. So in such cases it seems we can recognize my exercising the capacity, and the contrary's being produced, at the same time, without explaining my failure with reference to my not actually having the capacity in this situation.
Moline puts the thought here, as regards the dispositions of inanimate objects, in the following example: "it is not the case … that sugar has the property of being-soluble-under-all-circumstances-provided-nothing-external-interferes. Rather it has under all circumstances the property of being-soluble-under-certain-special-circumstances, namely, the ones under which it will invariably dissolve" (p 253); we can learn through experimentation what those circumstances are. Kern wishes to use this sort of thought to explain error; "der Irrtum" (ihr nach) "stellt folglich einen Fall dar, der nicht unmittelbar durch die Fähigkeit erklärt wird, die konstitutiv für ihn ist, sondern durch partikulare, kontingente Umstände, die erklären, weshalb jemand, der im Besitz der Fähigkeit ist, etwas zu erkennen, in der Ausübung dieser Fähigkeit gescheitert ist. Umstände, die das Scheitern der Ausübung einer bestimmten Fähigkeit erklären, wollen wir »ungünstige Umstände« nennen" (p 281). (The topic should be broader than just error, of course, since the person who concludes that he sees a barn in barn facade country is not, when he stands before the sole real barn there, in error. Nevertheless, Kern would like to say that in these circumstances he does not have the ability to recognize barns by glancing at them.) She proceeds by drawing an explicit analogy, at length, with dispositions, applying it then with little modification to rational capacities:
Wenn wir sagen, »Lisa kann schwimmen«, dann schließt das »kann« in dieser Aussage über Lisa ein, daß Schwimmen ein Akt ist, der als solcher von bestimmten Umständen abhängig ist und durch das Bestehen sogenannter ungünstiger Umstände verhindert werden. Wenn wir Lisa ins Wasser werfen, während sich 10 Meter hohe Wellen brechen und Lisa untergeht, werden wir nicht sagen, sie sei untergegangen, weil sie nicht schwimmen konnte. (p 291)
But what are we explaining here with reference to the particular, contingent circumstances? Not the success or failure of the actualization or exercise of the capacity, but the having of the capacity at all. This is quite clear in Moline's formula: if the circumstances are favorable, success is guaranteed. And if circumstances are not favorable, that doesn't mean that there was a failure in the actualization of the sugar's capacity to dissolve; it doesn't have the capacity to dissolve in those circumstances. (This is maybe clearer in a different formula of Moline's, actually, from the same page: the sugar is "under all circumstances capable-of-x-under-certain-special-circumstances"; it is not, however, capable-of-x-under-just-these-circumstances, so there isn't a question about any capability failing to be actualized, any more than the sugar fails to dissolve when it's sitting in the cupboard.) Likewise in Aristotle: he tells us when the possessor of a rational capability does in fact possess it. Contrast Jim's with his Schwungsteuerung; this is a mistake, not an unsatisfactory circumstance in which he just doesn't have the ability to ski.
If the only way we have of explaining why knowledge was not won, or in general a capability not actualized, is by pointing to a particular circumstance and saying, "in this circumstance, so-and-so did not actually have the capability we thought he did; his capability is intrinsically characterized by a certain set of favorable circumstances [cf Kern, p 292], and this is not among them", we seem to be excluding the possibility of error, and, in breif, making the sort of explanation of a state's not being knowledge that was employed in the barn facade context into the sole kind of explanation there is. It also becomes hard to understand such explanations as this: "Das Beste, was [Subjekte] erreichen können, ist, daß sie eine Fähigkeit haben, die sie de facto fehlerfrei ausüben" (p 292). It is hard to understand because we lack an understanding of the fehlerhaft exercise of a capacity—at least, the fehlerhaft exercise of a non-kinetic capacity.