Is Knowledge True Justified Belief?



Is Knowledge True Justified Belief?


Yes, despite the counterexamples. It is fair to say that before Gettier’s paper the TJB analysis of knowledge was the accepted theory. The theory was not regarded as a work in progress, as somehow incomplete, or vulnerable to counterexample. If not self-evidently correct, it was taken to be clearly and incontrovertibly correct. It is true there were some doubts about the necessity of the three conditions for knowledge, but not the sufficiency: nothing meeting those conditions could fail to be knowledge. That is why Gettier’s counterexamples came as a surprise, a shock, and a blow. If TJB doesn’t define knowledge, then what does! Some tried to retain the old analysis by claiming that the examples all involve defective justifications (and there was something odd about those alleged justifications), but most accepted that the counterexamples refuted the analysis. How could we have been so wrong—so confident and yet so misguided? Thus the hunt was on for a better theory, one immune to counterexample. But surely there is something funny going on here: is it possible that the pre-Gettier confidence was actually well placed and yet his counterexamples do show the conditions not to be logically sufficient? In what follows I will defend this position, which may seem not to exist in logical space. The key will be to distinguish between being a good theory and being a theory that provides necessary and sufficient conditions in every possible world: the latter is not required for the former. Or, to put it differently, a theory of what knowledge is isn’t the same as a logically watertight analysis of the concept of knowledge, i.e. the provision of a (complex) concept identical to the concept of knowledge. We can have a good theory (a true theory) of knowledge without it being immune to conceivable counterexamples concerning possible cases; and TJB is such a theory.

            The TJB theory tells us that knowledge is not the same as belief, which can be both false and irrational or unjustified. It distinguishes knowledge from mere opinion, because knowledge requires truth and a rational basis. It identifies the main components of knowledge, as they distinguish knowledge from belief (this can be useful when fighting sophists, say). It connects knowledge to the normative concepts of truth and justification, revealing what attempts at knowledge aspire to. These are important insights, adequate for most practical purposes, and they are recognizable by any normal person. By these criteria the TJB theory is a good theory. The existence of Gettier-type counterexamples does not defeat these insights (which go back to Plato). So what do they tell us? They tell us that in conceivable cases the conditions are not logically sufficient—there could be cases in which they are satisfied but the believer doesn’t know. Not that such cases are common, or even actually occur, or that they show that knowledge is not different from belief after all, but just that they exist in logical space: we can imagine such cases and our intuition tells us that they don’t qualify as knowledge. The question is why this matters: so what if the theory doesn’t cover every imaginable case? Was it ever intended to? Can’t it be a good theory and not cover all of logical space?  What if we said it was only meant to cover actual or typical or central cases of knowledge? If we had said that knowledge is just belief, we would face the objection that this fails to cover even the most common and central cases; but Gettier cases are admittedly uncommon and not central, involving bizarre kinds of justification. A good theory needs to get the basic elements of knowledge right (truth and justification), but does it need to cover all conceivable cases, no matter how contrived or irrelevant to daily life? Can’t it be more like an empirical scientific theory, which doesn’t purport to cover all of logical space?

            Before pursuing this line of thought let’s remind ourselves of some analogous cases in which an illuminating philosophical theory runs into unexpected trouble with the logically conceivable. Take the causal theory of perception: in order for a sensory experience to count as a perception there must be a causal connection between the experience and the object; it isn’t enough to see a clock that a clock be there and you have an experience as of a clock. This theory rightly distinguishes perception from veridical hallucination and it points to the indispensible role of causation in constituting perceptual facts. (The same can be said about memory: the memory impression must be caused by an earlier event in order to count as remembering it.) But no sooner was this theory propounded than counterexamples to it were constructed (note the word): we had the problem of deviant causal chains. Does this show that the causal theory of perception is a bad theory? Not at all: it merely shows that the conditions it identifies don’t logically guarantee perception in every possible world—they are not logically sufficient. But in all actual cases there are no such deviant causal chains and the theory works just fine; more important, it identifies the main elements of the perception relation, illuminatingly so. We shouldn’t throw out the theory simply because counterexamples to it can be produced: it gives us important information about what perception consists in. Or consider Bernard Suits’s definition of a game: an activity in which inefficient means are adopted to achieve an end (I oversimplify). Suppose counterexamples could be contrived showing that logically possible cases could satisfy these conditions and not be games (not that I think this can be done). Does that imply that Suits failed to identify the central element in what distinguishes a game from what he calls a “technical activity”? Obviously not; and all actual games may well obey his theory (and no non-games). Thus we should distinguish theoretical adequacy from the provision of logically necessary and sufficient conditions. We detach the adequacy of a theory from any claim of complete modal coverage. We separate the project of providing a good theory of games (the things themselves) from the project of providing a (complex) concept identical to the concept of a game. These are quite different enterprises—one about the nature of things as they actually exist, the other about the content of a concept that we can extend to merely possible cases. Both enterprises may be worth pursuing, but they should not be confused—hence the failure to do the latter does not undermine the success of the former. A good theory of X need not be a good theory of the concept of X that covers every conceivable application.[1]

            Let me illustrate the distinction by reference to a well-known paradigm—scientific natural kinds. Suppose a chemist announces that water consists of H2O. That is a very good theory: it connects water to molecular theory and it distinguishes water from other substances, among other things. Then a philosopher comes along and objects as follows: couldn’t there be some other chemical combination that also qualifies intuitively as water, as it might be H3O, so that the H2O theory doesn’t provide a logically necessary condition? Moreover, couldn’t hydrogen and oxygen molecules be distributed in a ratio of two to one but be so spread out as not to form what we would intuitively call water, so that the condition isn’t sufficient? The point is not so much that these are genuine counterexamples to a claim of logical necessity and sufficiency—though they do appear to be—but that they are irrelevant to the chemist’s claim. For the chemist was not asserting that, as a conceptual truth, water is H2O in all possible worlds; his claim was more limited than that (no matter what a philosopher may expect). His claim was more like this: the theory identifies the main elements of water, distinguishing it from other substances, and connecting it with molecular theory. It’s about actual water and what it’s made of not about how things are in possible worlds. He might go as far as to say that his claim is a nomological necessity—a lawlike truth about the actual world—but he has no interest in venturing claims about how things might be out there in logical space. His attitude towards the counterexamples cited will be one of sublime indifference, given that they do nothing to undermine his claim to winning a Nobel Prize in due course. Or consider heat and the theory that heat is molecular motion. Someone might object that there are conceivable cases in which we have heat without molecular motion and molecular motion without heat: some possible things that we would intuitively count as heat are correlated with some other physical phenomenon, and in some conceivable circumstances there could be molecular motion but no heat. Again, it doesn’t matter whether the counterexamples are persuasive; the point is that they don’t matter so far as the physical theory is concerned. That theory is not intended as a theory of how the concept of heat applies in imaginary possible worlds; it’s about heat as it actually exists and acts here and now.

            Old hands will no doubt be clamoring to explain about the necessity of identity: if the scientist is making a claim of identity, then he is committed to rejecting the counterexamples, so that they do count against his theory if they are genuinely possible cases. But why should we foist any such interpretation on his words (or thoughts)? This identity business is philosophy talk not chemistry talk. He said that water consists of H2O and heat is a manifestation of molecular motion; and these don’t force any modal claims on him—he might readily allow that water and heat could be different in other possible worlds.[2] Similarly, the epistemologist need not claim that knowledge is identical to true justified belief, which would land him in trouble with the Gettier counterexamples, given the necessity of identity; his claim could rather be that these are the main elements of knowledge, or that nearly all knowledge fits this analysis, or that it is a matter of natural law that knowledge is TJB, or that the central cases of knowledge conform to the theory, etc. He might cheerfully allow that the theory does not cover all conceivable cases, even acknowledging that the concept of knowledge is not identical with the concept of true justified belief. After all, philosophers only recently started fretting about necessary and sufficient conditions for concepts to apply: before that they were content to offer theories of things. In fact, this practice started around the middle of the twentieth century, possibly as a result of the logicist program in philosophy of mathematics—the attempt to rigorously define mathematical notions in terms of logic. Here the idea of a priori necessary and sufficient conditions had some purchase (see Russell’s theory of descriptions as an offshoot), and it was natural to hope for something similar in other areas of philosophy. But this was not the project of philosophy in earlier times, or independently of certain trends in analytical philosophy (Frege could be said to be the originator); instead people were trying to produce adequate theories, as judged by the usual criteria. The demands on conceptual analysis in terms of logically necessary and sufficient conditions are very stringent, but the philosopher need not be wedded to that methodology; and this means that there is room for a type of theory that doesn’t have such lofty goals. We can thus accept that TJB provides a good theory of knowledge without insisting that it captures all conceivable cases, either through lack of necessity or lack of sufficiency. This is what knowledge basically, centrally, paradigmatically, is—even if there are odd cases that don’t quite conform to it. It can be argued that not all knowledge requires belief (uncertain knowledge, animal knowledge), that not all knowledge requires justification (direct knowledge of one’s own mental states), and that not all knowledge even requires truth (can’t someone know that the golden mountain is golden, though this proposition is neither true nor false?): but these are not central cases, so they don’t undermine the general goodness of the TJB theory. Similarly, Gettier-type cases involve strange kinds of defective justification (e.g. Russell’s example of the accidentally accurate stopped clock); they are by no means common or central. This explains why no one thought that the TJB theory was vulnerable till Gettier came along—it wasn’t vulnerable, given its aims. What Gettier in effect did was force us to distinguish between two projects: giving a sound theory of knowledge (the thing) and providing necessary and sufficient conditions for the application of the concept of knowledge in all conceivable cases. We can engage in both projects but we shouldn’t let one be hostage to the fortunes of the other. We certainly shouldn’t give up on providing a theory of knowledge just because we can’t find necessary and sufficient conditions for the application of the concept. The TJB theory is a fine theory by any standards, a solid philosophical achievement, despite the counterexamples.[3] Indeed, we might applaud it for being precise enough to allow the construction of counterexamples to it (a simple true belief theory will not lead to the kind of ingenious cases invented by Gettier and others). The same is true for the causal theory of perception and memory and Suits’s theory of games (also Grice’s original analysis of speaker meaning). These are all great theories, exhibiting the power of a priori philosophical analysis, despite the possibility of clever counterexamples. One might be tempted to conclude that there will always be counterexamples in philosophy, but that doesn’t prevent us from coming up with excellent theories. There are counterexamples to the claim that tigers are striped and have four legs, but that doesn’t mean that this “theory” is defective in any way when properly understood.

[1] Compare the case of sentences: we could define a sentence as a meaningful combination of words expressing a complete thought. Is this definition sufficient? Isn’t Shakespeare’s “But me no buts” a meaningful combination of words expressing a complete thought, but it’s not a sentence (it isn’t grammatical)? It’s like “On me no ons” or “It me no its”. So a meaningful combination of words expressing a complete thought need not be a sentence. Fair enough, one might say, but that hardly undermines the general correctness of the definition in question. It only fails to apply in the oddest of cases.  

[2] A different kind of example: it might be a good theory of life to say that life is the operation of selfish genes, i.e. DNA molecules, while allowing that on other planets, or in other possible worlds, reproduction works differently with no DNA involved. It’s a good theory because of its explanatory power and unification of macro biology and microbiology, but it need not aspire to metaphysical necessity. In philosophy too a good theory might have many such “counterexamples”, just as a bad theory may have none (e.g. “knowledge is a very special kind of belief”).

[3] As Kripke would say, something can be a good “picture” without being a watertight “theory”; or as I prefer, something can be a good theory without being a watertight conceptual analysis. And it isn’t that such a theory aspires to being conceptually leak-proof.

2 replies
  1. Mike R.
    Mike R. says:

    This is really interesting! You say that watertight conceptual analysis is not necessary for proving a good and even true theory of knowledge. But do you think that there is a watertight conceptual analysis of knowledge? (Do you wish to be noncommittal on this question?) And if there is, are you saying that it is nevertheless not worth pursuing? (You’re certainly saying that pursuing it is not necessary for providing a good theory of knowledge.)

    • Colin McGinn
      Colin McGinn says:

      I mainly want to separate the two projects. Actually, as the last footnote says, I think it is possible to analyze the concept using the idea of non-accidental truth. A certain amount of vagueness (flexibility) is acceptable in this.


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