Wednesday, 3 August 2011

Explicit knowledge and its transmission

Another work in progress chapter.

Explicit knowledge and its transmission

The goal of knowledge, justification and the avoidance of luck

Medical science aims at truth. Why? Here is one reason. Medicine aims not just to understand the nature of the world but to intervene in it. For a given therapeutic aim and a belief – or set of beliefs – about how to bring it about, achieving that aim will in general depend on the truth of the belief (or set). Success given merely false beliefs would require the compensation of additional good luck. In general, truth unlike falsity is conducive to success. But if true beliefs explain therapeutic success, why aim not just for true beliefs but, more than that, knowledge? What is the value of knowledge?

In this chapter I outline some key issues in the analysis of knowledge which start from this question. One key problem is this. In the main knowledge is conveyed by testimony – through enculturation and upbringing, and explicit teaching and learning – and yet intuitive approaches to the analysis of knowledge which aim to capture personal responsibility for it would make this impossible.

One answer to the question raised comes from an intuition about the nature of knowledge. Knowledge can be undermined by luck. Suppose that a tennis fan forms an irrational conviction about who will be the winner of next year’s Wimbledon tournament which turns out, by chance, to be correct. His true belief, in such a case, is not knowledge. Whilst he may claim that he knew who would win, if the facts are as just described (that it was merely an irrational conviction), he did not know. Whatever has to be added to true belief to yield knowledge should address this widely shared intuition.

A longstanding traditional view holds that the addition is justification. Knowledge is justified true belief. The tennis fan lacks knowledge because he lacks a suitable justification for his belief, a justification that rules out the need for luck for the belief to turn out to be true.

Justification also plays a second role. It provides a means of aiming at true beliefs. It is one thing to worry that one’s beliefs about the efficacy of rival surgical techniques may not be correct, but quite another to work out how to avoid error. It would not be helpful to be told to replace any false beliefs with true beliefs. To hold a belief is to hold it to be true. (To hold that something is not the case is not to believe it.) Thus beliefs which are, in fact, false are not be transparently so to someone who holds them. But the advice that one should ensure that one holds only beliefs that are justified is helpful. And by aiming at justified beliefs one should in general succeed in reaching true beliefs since justification is, in general, conducive of truth.

This approach broad strategy is exemplified in the way Descartes approaches his epistemological project: the method of doubt.

Several years have now elapsed since I first became aware that I had accepted, even from my youth, many false opinions for true, and that consequently what I afterward based on such principles was highly doubtful; and from that time I was convinced of the necessity of undertaking once in my life to rid myself of all the opinions I had adopted, and of commencing anew the work of building from the foundation, if I desired to establish a firm and abiding superstructure in the sciences...

But, to this end, it will not be necessary for me to show that the whole of these are false--a point, perhaps, which I shall never reach; but as even now my reason convinces me that I ought not the less carefully to withhold belief from what is not entirely certain and indubitable, than from what is manifestly false, it will be sufficient to justify the rejection of the whole if I shall find in each some ground for doubt... [Descartes **: **]

Realising that some of his beliefs are probably false, but that he will not be able to determine which directly (for the reason above), Descartes decides to reject all those beliefs whose justifications are deficient. Since those cannot be knowledge this fits the role of justification outlined so far. But there are two further features of Descartes’ project which are attractive but misleading.

First, he takes his target to be anything that is not entirely certain and indubitable. Second, the justifications for beliefs he considers are those fully available to him (in his study) a view now called epistemic internalism. Taken together these drive him to conclude that the only thing that resists his method of doubt is expressed in the cogito: he thinks, therefore he must exist. Cogito ergo sum.

When reflecting on knowledge in the context of a philosophical discussion, even medical students tend to adopt both of these assumptions. They concede that they do not really know anything of which they are not certain and that certainty is a matter of, for what, they can personally vouch. This, however, rules out all but the most basic medical knowledge and threatens to undermine the point of much medical education such as lectures and textbooks. Whatever knowledge is, it can be shared and taught. In short, one can gain knowledge second hand through testimony: any form of transmission of knowledge through the reports of others contrasting with perception, reasoning, whether inductive or deductive, and memory. This obvious places constraints on how best to understand knowledge.

There is a second reason to be wary of the internalist version of the traditional picture. In the 1960s Edmund Gettier showed how to construct counter examples in which a subject had a true belief and a justification for it but the justification only worked through the intervention of luck. Smith and Jones have applied for a job [Gettier 1963]. Smith has good reason to hold that Jones will get the job and has ten coins in his pocket from which he concludes that the successful applicant has ten coins in his pocket. By chance, he himself gets the job and has ten coins in his pocket. Did he know that the successful applicant has ten coins in his pocket? No. A justification may fail to rule out the need for luck which undermines knowledge.

Diagnosis, testimony and internalism

Why does testimony not fit the internalist assumption made by Descartes (and the medical students) that justification depends only on factors which are reflectively accessible to the knower? The problem is that an individual cannot do enough to vouch for the status of knowledge transferred. For this to be possible, testimony would have to be justified in terms of, perhaps by being reduced to, processes which do fit an internalist analysis. But this is not possible.

Suppose, for example, that internalist accounts could be given of perception and induction (neither of which seems plausible). An internalist account of testimony would then be possible if testimony could be reduced to a combination of perception (of others, of their utterances, etc.) together with inductions from their previous reliability. David Hume attempted to outline just such a defence of testimony in his Enquiries Concerning Human Understanding [Hume 1975: 109-116]. But as the philosopher Tony Coady convincingly argues, no such attempt can work [Coady 1992: 79-100]. I will mention two criticisms of Hume which suggest the principled difficulty of any such attempt.

The first objection is that Hume’s defence depends on establishing inductive correlations between past instances of testimony and the truth of beliefs successfully communicated. But there is, in fact, much less evidence available to individuals than Hume supposes. Peter Lipton puts the point thus:

Hume’s discussion systematically hides the fact that our evidential base is far too slender to underwrite in this way even a small fraction of the testimony we rightly accept. Perhaps the main device Hume uses here is to appeal to the correlations we have observed to obtain between various types of testimony and the facts. This appeal to communal observation closes a vicious circle, since you can only in general know what others have observed on the basis of their testimony. The only evidence that you can legitimately appeal to consists of correlations between what you yourself have heard and what you yourself have seen, and this provides far less evidence than would be required to support inductively the wide range and variety of generalisations that would cover all the unchecked testimony you actually accept. [Lipton 1998: 15]

A second line of objection is that the observations that an individual might make are not themselves free from past testimony and thus cannot be used to justify it independently. The quickest argument for this is that observations are framed in language and language is taught through testimony.

Thus it seems that there is little hope of offering a non-question-begging justification of testimony, in internalist terms. Instead, whatever local checks might be carried out, we have to take the general reliability of testimony as a whole on trust. Successfully learning something by testimony is simply hearing in another’s utterance that something is the case. Whilst the ignorance or insincerity of a teacher or witness undermines such transmission of knowledge, one does not, and in general cannot, first ensure their knowledge and sincerity in non-question-begging, non-testimony-based terms.

The moral of this seems to be that one should reject internalism and argue that either justification, or something else playing that role, depends on factors that are external to a person.


The most familiar version of epistemic externalism is reliabilism, according to which knowledge is true belief arrived at by a reliable method. Crucially, the knower need not know that the method by which she arrives at her beliefs is reliable (or anything about the method) as long as it actually is. And there is nothing akin to a justification for the knower (for which reason it is taken to be a rival to, not a variant of, the traditional justified true belief analysis). It goes some way to address the worry that individuals do not know enough of the pedigree of what they are usually taken to know. If a teacher is reliable, it is possible to gat knowledge from them second hand. But reliabilism faces the challenge of specifying just how reliable a method must be to deliver knowledge. Anything less than 100% reliable reintroduces the need for some luck for a resultant belief actually to be true. But restricting methods to 100% reliable threatens to make knowledge impossible.

A more promising recent version of externalism has recently been articulatedby John McDowell. Like traditional internalists he does think that reasons have an important role in knowledge. Internalists, however, construe justification as something under the complete control of a subject without need for luck, although Gettier cases suggest that luck is needed to promote a justified belief to a truth. McDowell rejects the view that:

reason must be credited with a province within which it has absolute control over the acceptability of positions achievable by its exercise, without laying itself open to risk from an unkind world. [McDowell 1998: 442]

On his account, even to have a justification - a ‘standing in the space of reasons’ - requires some luck. One is lucky not to be looking at an unrepresentative physiology or in distorting lighting conditions or not to be in the presence of a capricious lecturer. But given that initial luck, no further luck is required to transform one’s situation-based justification into true belief and hence knowledge. This idea is clarified by three further points:

1. A comparison with practical reason.
2. An anti-intellectual view of knowledge.
3. An anti-reductionist view of the kind of philosophical insight needed in epistemology.

Firstly, McDowell’s proposal about our authority over our justification can be compared with a view of practical reasoning which already seems natural:

The concept of what one does, understood as applying to one’s interventions in the objective world, cannot mark out a sphere within which one has total control, immune to luck. It is only if we recoil from this into a fantasy of a sphere within which one’s control is total that it can seem to follow that what one genuinely achieves is less than one’s interventions in the objective world. [ibid: 406 fn 16]

Although our actions are the result of an interplay between, on the one hand, our beliefs and desires and, on the other, contingent or lucky features of the world which shape the possibilities for action, this is not taken in general to undermine our responsibility for our actions. Likewise our epistemic status.

Secondly, McDowell combines his view that having an epistemological standing depends at least in part on a relation to the world with an anti-intellectualist view of knowledge. It can be brought out by considering his attitude to a contrast between what he terms ‘mediated’ and ‘unmediated epistemic standings’. If it existed, an unmediated standing would be one which was foundational, or an ‘absolute starting point’ of the sort hoped for by the Logical Positivists. That, sadly, is mere a myth and leaves only mediated standings, by contrast, which stand in rational relations to each other. Even perception is a ‘mediated standing’ because observation is theory dependent.

On one view of them, a mediated standing in the space of reasons is one for which an argument can be given, by the knower, from premises which do not beg any questions to a claim to knowledge. The argument might thus move from premises about how things look – their mere appearances about which which one supposedly cannot be mistake – to a conclusion to the effect that the subject can see that things really are thus and so. On this view, the space of reasons in general consists in the explicit arguments subjects can offer for their beliefs.

McDowell does not deny that there are some arguments relevant to one’s epistemological status. If a subject sees (or has seen; or hears; or has heard) that something is the case, then it must be the case. Furthermore, to be a subject capable of knowledge at all, he or she must be sensitive to the power of reasons. But he does reject the idea that the epistemic position of seeing or hearing that something is the case can be reduced to or constructed out of something more basic via an argument that the subject of the position could provide.

In the case of testimony, it is particularly clear that a hearer is not in general in a position to rule out possible sources of error in what a speaker says or other factors that would imply that a speaker does not know what he or she affirms. Thus, in general, a hearer cannot provide an argument from what he or she hears said to its truth. Nevertheless when unbiased by mistaken assumptions about the nature of knowledge, it seems clear that testimony can indeed provide knowledge. (Likewise one may not be able to frame an argument from the nature of the lighting conditions to the reliability of appearances, but, in good lighting, seeing how things look can furnish one with knowledge.)

McDowell’s response to this tension is to suggest that the attempt to give a reductionist account of having justification is mistaken.

The idea is, then, that one’s epistemic standing with respect to what one comes to know by testimony consists in one’s, say, having heard from one’s informant that that is how things are; not in the compellingness of an argument to the conclusion that that is how things are from the content of a lesser informational state. [ibid: 436]

So – and this is the third point flagged above – the tenor of the analysis runs in the opposite direction to what is normal. Rather than attempting to build up an analysis of knowledge by asking what more primitive concepts need to be combined to yield it, he takes knowledge to be a basic concept and then explores its relation to other concepts such as reason, justification and truth.

Reasons and responsibility

Knowledge can be undermined by luck. Even true beliefs based on the wrong or no reasons do not amount to luck. And hence there has been a focus on the reliable methods of acquiring beliefs such as looking to justificatory reasons. But on an internalist view the way we acquire most of our knowledge of the world – second hand through explicit teaching and implicit enculturation – is impossible. A more nuanced account accepts that sensitivity to reasons plays a role in knowledge but that one can simply be in a position to see or hear what is the case.

This, however, does not mean that a knower can simply be passive in the face of experience. There may be reason to believe, for example, that lighting conditions are misleading or that a RCT has been discredited or is from a unreliable laboratory or that a once reputable textbook is now out of date. Even though one can acquire explicit knowledge second hand without being able to offer an argument for the reliability of the source, one still needs to exercise epistemic responsibility in keeping up to date with changing evidence.

Coady, A. (1992) Testimony: a philosophical study, Oxford: Clarendon Press.
Descartes, R. (1986) Meditations on first philosophy, Cambridge:Cambridge University Press.
Gettier, E.L. (1963) ‘Is justified true belief knowledge?’ Analysis 23: 121-123
Hume, D. (1975) Enquiries concerning the human understanding and concerning the principles of morals, Oxford: Clarendon Press.
Lipton, P. (1998) ‘The epistemology of testimony’ Studies in History and Philosophy of Science 29: 1–31.
McDowell, J. (1998) Meaning knowledge and reality, Cambridge, MA: Harvard University Press.