Maximally Accurate and Comprehensive Beliefs
To know one must not lack important information. This test may not always resolve disputes over whether someone knows something, but it does suggest that as one’s grasp of a situation becomes more and more complete, it ought to become more and more difficult to deny that one has knowledge.
Merely accumulating truths is not enough, however. One can acquire numerous truths about a situation and still not be in a position to know if the truths are unimportant. Moreover, how truths are connected is itself information, indeed, often crucial information.
Two-thirds of the way through a mystery novel, it may be obvious to readers that the detective has a true belief that the victim’s childhood friend is the guilty party and obvious as well that the detective has discovered all the essential clues—the weapon, the jimmied lock, the empty safe, and so on. Nonetheless, if the detective is unable to piece together these clues into an accurate picture of when, how, and why the crime was committed, readers are likely to think that the detective does not yet have enough information to know that the childhood friend is the guilty party. The significant gap in his information is how the bits of information in his possession fit together.1
So, sheer quantity of information is not what makes it difficult to deny someone has knowledge. The point, rather, is that as someone comes to have an increasingly comprehensive grasp of a situation, where this involves not only having the important pieces of information but also seeing how they are linked, it should become increasingly difficult to maintain that she doesn’t know.
Let’s push this thought to its limit. Imagine Sally’s beliefs are as accurate and comprehensive as it is humanly possible for them to be. She has true beliefs about the basic laws of the universe, and in terms of these she can explain what has happened, is happening, and will happen. She can explain the origin of the universe, the origin of the earth, the origin of life on earth, the mechanisms by which cells age, and the year in which the sun will die. She even has a complete and accurate explanation of how it is that she came to have all this information.
Consider a truth Pcells about the aging mechanisms in cells. Sally believes Pcells, and because her beliefs about these mechanisms are maximally accurate and comprehensive, there are few gaps of any sort in her information, much less important ones. Thus, she knows Pcells.
According to many theories, however, a true belief can be an instance of knowledge only if it has a proper ancestry, with there being competing views about what the required lineage is. Some maintain that the belief must be caused in an appropriate way by the facts that make it true; others hold that it must be the product of cognitive processes that are generally reliable about matters of the kind in question; still others say that it must be the product of cognitive faculties functioning as they were designed to function.
It is consistent with the Sally story as told that her beliefs about how cells age were not caused by the facts that make them true and were not the products of reliable processes or properly functioning cognitive faculties. Rather, it may have been some combination of curious processes and unlikely events that led to her having these beliefs. But Sally is fully aware that however strange and unlikely this history may be, in her case it led to her having maximally accurate and comprehensive beliefs.
Ancestral accounts are nevertheless committed to denying that she knows Pcells or for that matter much of anything else. Indeed, on the assumption that the rest of us often have a good many true beliefs with the required ancestry, these accounts imply that we know more about the world than Sally does. By contrast, the adequate information view implies that Sally has far greater knowledge than the rest of us even if the way she acquired it is unusual. But if so, no special pedigree is needed for knowledge. Knowledge can be a mutt. One has to have adequate information, but there is no privileged way of getting it.
Intuitions can and do vary, however, especially about stories far removed from the ordinary. So, the aim here is not so much to set up a battle of intuitions but rather to illustrate differences between approaches. According to reliability theories, it does not matter that Sally has as accurate and comprehensive grasp of Pcells as it is possible for a human to have. What matters is whether her beliefs about Pcells were reliably produced. By contrast, on the adequate information approach, having beliefs that are reliably produced is a frequent accompaniment of knowledge but not a strict prerequisite. Since there are few if any gaps, much less important ones, in Sally’s information about Pcells, she knows.
This story can be also used to highlight differences with other accounts of knowledge. Consider tracking theories. It is possible for Sally’s beliefs to be maximally accurate and comprehensive and yet not track the truth in close counterfactual situations. But then, according to tracking accounts, she does not have knowledge, whereas on the adequate information approach, this would again seem implausible. She has maximally accurate and comprehensive beliefs about the origin of the universe, how life came into existence on earth, and the mechanisms by which cells age, and if unusual circumstances led her to have these beliefs, she also has maximally accurate and comprehensive beliefs about these circumstances. In particular, if her beliefs would not track the truth in close counterfactual situations, she is fully aware of this and has true beliefs about why they would not do so. She is aware, in effect, of the fragility of her information. Fragility, however, is not necessarily incompatible with knowledge. Think by analogy of powerfully precise measuring instruments whose workings are so delicate that if the operating conditions were altered so that there were even minor vibrations present, their readings would no longer be accurate, but as long as there are no such vibrations, these counterfactual inaccuracies are beside the point. So it may be with Sally’s beliefs.2
What about justification-based theories of knowledge? Since Sally can fully explain the origin of the universe, the origin of the earth, and the mechanisms by which cells age, it might seem that her beliefs about these matters must be justified. On the other hand, some of the most familiar accounts of justified belief imply that one’s beliefs are justified only if they are structured in a specific way, but it’s not a foregone conclusion that Sally’s beliefs have the required structure.
Consider classical foundationalist accounts, which imply that beliefs are justified only if they can be adequately defended in terms of self-justifying beliefs, where the only beliefs that are self-justifying are ones about simple necessary truths and current psychological states. There is nothing in the story about Sally that guarantees that her beliefs about the origin of the universe, how life came into existence on earth, and the mechanisms by which cells age can be adequately defended in terms of such beliefs. Nor is there anything that prevents Sally herself from being fully aware that her beliefs cannot be so defended despite being maximally accurate and comprehensive.
Or consider accounts that require justified beliefs to be coherent, where coherence is a matter of the logical and probabilistic relations among the beliefs, and then go on to use intellectual virtues such as simplicity and conservatism to distinguish among equally coherent but competing sets of beliefs. There again are no assurances that Sally’s beliefs meet these requirements. A set of beliefs that is maximally accurate and comprehensive is not necessarily the most coherent, simple, and conservative. Moreover, once again, Sally may realize all this. She can be aware that her beliefs, although maximally accurate and comprehensive, do not satisfy the requirements of coherence accounts of justified beliefs.
The apparent lesson is that just as a special ancestry is not required for true beliefs to count as knowledge, neither is a special structure. I say “apparent” not only because intuitions about cases as extraordinary as this have to be treated with a grain of salt, but also because every story is incomplete. The story about Sally is no exception, and it might turn out that the details cannot be filled in without implying that her beliefs have other merits—in particular, merits related to ancestry or structure.
Might it be possible to argue, for example, that Sally’s beliefs couldn’t possibly be maximally accurate and comprehensive unless they were reliably generated? This would not be a simple argument to make, however, at least not if the reliability in question is supposed to be the kind that makes a true belief into a plausible candidate for knowledge. Reliability theorists go out of their way to point out that a process that in fact produces only true beliefs is not thereby necessarily reliable in the sense they have in mind.3 So, it is not enough merely to observe that the processes generating Sally’s beliefs have yielded only true beliefs.
On the other hand, there may be ways of arguing for a more modest conclusion, in particular, that the Sally story cannot be filled in without assuming an orderly universe that she has interacted with in lawlike ways, which in turn imply that her beliefs have to be the products of processes that meet at least minimal standards of reliability. But if so, so be it. Indeed, so much the better, since this makes it all the easier to accept that Sally has knowledge. Not only does she have views about Pcells that are as comprehensive and accurate as is humanly possible, in addition her views, although arrived in a highly unusual manner, have to be the products of lawlike interactions that meet minimum conditions of reliability.
An argument of this sort, however, would not affect the key point for purposes here, since the simplest and best explanation of why Sally knows is not that her beliefs are products of processes that are reliable in this minimal sense. All sorts of true beliefs meet this condition without being plausible candidates of knowledge. The explanation, rather, is that her beliefs are maximally accurate and comprehensive, and hence she lacks no important information. What such an argument, if successful, does reveal is a constraint on just how unreliable a set of processes can be and yet still produce maximally accurate and comprehensive beliefs.
Just as it may be possible to argue that maximally accurate and comprehensive beliefs inevitably satisfy minimal standards of reliability, so too it may be possible to argue that they inevitably meet minimal standards of justification. Donald Davidson maintained that it is not possible to attribute beliefs to others, much less knowledge, without the attributed states being largely coherent.4 Even if Davidson overstates the point and the nature of belief doesn’t itself produce such strong constraints on the structure of one’s beliefs, the world may do so, or more cautiously may do so to the degree that the beliefs are accurate and comprehensive. One line of argument, for example, is that it is not possible for beliefs to be maximally accurate and comprehensive without reflecting whatever orderly structure the world has, and this orderliness in turn ensures that the beliefs meet minimal standards of coherence. Another line of argument, more foundationalist in spirit, is that maximally accurate and comprehensive beliefs cannot help but be derived in part from experiences of the world, since without such an experiential base, they could not have the content they need to have in order to be accurate and comprehensive.5
Once again, if such arguments can be made, they make it all the easier to accept that Sally has knowledge. Her beliefs may not be tethered to experience in quite the way that foundationalists typically insist and may not be coherent in quite the way that coherentists prefer, but they do have to be at least minimally coherent and tethered to experience. Thus at least in these respects, Sally begins to look at least a little more like an ordinary human knower.
Suppose, however, we assume the worst. Assume that all such arguments fail, and hence it is in principle possible for Sally’s beliefs to be maximally accurate and comprehensive and yet not be even minimally coherent or minimally tied to experience or the products of even minimally reliable processes. What then? Might not we then be more reluctant to grant that Sally knows? Maybe, but even if this is so, why put much faith in this intuition, given that the situation being imagined is so far removed from our everyday attributions of knowledge and given also that her beliefs are as accurate and comprehensive as it is possible for human beliefs to be?
On the other hand, a dismissive response of this sort can all too easily be returned in kind, the rejoinder being, why put much faith in the intuition that she does know, given that the situation is so far removed from the ordinary and given that her beliefs don’t meet minimal standards of coherence, reliability, or connectedness with experience? The real challenge, once again, is to avoid being forced into a position where we are simply trading intuitions.
So, let’s agree to keep open the possibility that even if Sally’s beliefs are as accurate and comprehensive as it is possible for human beliefs to have, something nonetheless might interfere with her knowing. As a first step toward seeing how the adequate information view might accommodate this possibility, I will now turn to an extreme story at the opposite end of the spectrum from the Sally story, one involving not an abundance of information but rather a scarcity.