The Gettier problem and the internalism / externalism divide 91 assumed that a belief could be justified and false. Chisholm (1977)

sug-gested the same.⁶⁸ The point has been emphasised, and argued for, in the recent literature (Sosa, 1985, 239–40, Sturgeon, 1993, 160–1, Zagzebski, 1994, 69,Merricks,1995, 845). We will present an argument to that effect in the context of modal accounts of knowledge (4.2).

Externalist theories of knowledge appeared in the wake of the Gettier problem (Goldman, 1967;Unger, 1968;Armstrong, 1968; Dretske,1969).

They provide an alternative way out of Ur-foundationalism. They pre-serve the idea that knowledge requires an infallible mark of truth, but abandon the idea that the mark has to be discernible. Unger(1968, 158) states the view in the most general terms: one knows if and only one’s be-lief is non-accidentally true. Given Hume’s predicament, whether one’s belief is non-accidentally true is not a discernible property of a belief. But it is an infallible one: trivially, one’s belief cannot be non-accidentally true and false. Such views are in position to avoid Gettier problems.

The fact that on the externalist view, the knowledge making property is not discernible has been the source of recurring dissatisfaction (see e.g.

BonJour, 1980, Cohen, 1984, Pollock, 1986, 116–7). Yet everybody has granted that the justified true belief analysis of knowledge was wrong.

This has prompted a number of authors to defend what I call mixed internalist views.

2.5.4 A dilemma for mixed internalist views

Amixed internalist view is a view according to which knowledge re-quires botha discernible mark of truthandan infallible one. By Hume’s predicament, no property can play both roles. So there will be two con-ditions on knowledge: that the belief bears a discernible (fallible) mark of truth, and that it also bears an (indiscernible) infallible mark of truth.

Such views face a dilemma.

68. Cf.Chisholm(1977, 103): “if it is possible for some propositions to be both evident and false, then, as we shall see, it is also possible for some a personSto accept a true and evident proposition without therebyknowingthat the proposition is true”. See also Chisholm(1966, 23).

One the one hand, the two conditions may be independent in a way that allows accidental coincidence. The problem is illustrated by theno false assumptionaccount (Clark,1963;Harman,1973;Lycan,2006):

No false assumption Sknows thatp iffS’s belief thatp is justified, and no assumption inS’s justification forpis false.

(What counts as an “assumption” in one’s justification is a delicate issue.

But there is a reading of it on which the point we are about to make is true.

This is all that is needed here to illustrate the problem faced by mixed internalist views with independent conditions.) WhetherS is justified, on the view under consideration, is an internal matter: it depends, say, on whether the subject has a network of experiences and beliefs which bears some adequate evidential relations to the subject’s belief thatp. It is assumed to be discernible. By contrast, the truth of all assumptions involved in one’s justification is not: an ideally attentive subject could mistakenly believe the assumptions to be true. We may also assume that the truth of all assumptions entails the truth of the belief.⁶⁹ The two conditions are satisfied by coincidence in cases such as Ginet-Goldman’s fake barns story (Goldman, 1976, 772–3).⁷⁰ The subject is justified in believing that something is a barn by his experience, and he assumes that the visual appearance of the building is not misleading. The assumptions, and others we may naturally take the subject to make, are true.⁷¹ Yet it is a coincidence that the two conditions are satisfied: if the subject had looked at the next building, he would have had a similar justification, but the corresponding assumptions would be false. The subject does not know, and the analysis turns out to be insufficient. The moral of the example is that a view according to which knowledge requires to satisfy two conditions, an infallible and a discernible one, is liable to face Gettier-style counterexamples if the two conditions can be satisfied by

69. If one believespbecause one believesj, for instance, then one presumably assumes the material conditionalj→p. But the truth ofjand j→pimpliesp.

70. See p.159below for a description of the case.

71. Here we assume that the subject’s justification does not involve the assumption thatotherbuildings in the area do not have deceptive appearances. That this holds about some natural notion of assumption is granted byLycan(2006).

2.5. The Gettier problem and the internalism/externalism divide 93 coincidence. (I will defend this point further in sec. 4.4.4.)

On the other hand, an analysis on which the presence of an infal-lible mark entails the presence of a discernible one is just a species of straightforward infallibilism. Suppose, for instance, that having a visual experience that p that is appropriately caused by the fact that p is a relevant infallible mark for beliefs that p. Any belief that instantiates the mark instantiates a putative discernible mark, that ofhaving a visual experience that p. Now it may look as if the suggested account of visual knowledge thatpis a mixed internalist one: one should have a visual experience that p(discernible condition), and the experience should be caused by the fact thatpin the proper way (infallible condition). If the analysis is presented with belief and truth as independent conditions, it may even look as if the fourth condition is a minor clause to deal with bizarre counterexam-ples — an “anti-Gettier codicil” (Pritchard, 2010). But in fact, the fourth, infallibilist, condition entails the truth and the justification ones. The infallibilist clause is doing the real work; justification is epiphenomenal.

Thus mixed internalist views face a dilemma. Either they put forward a genuine conjunction of conditions, and they are likely to face Gettier-style counterexamples. Or they put forward what amounts to a single infallibilist condition that entails some discernible property, and their account is only superficially different from straightforward externalist views. In the latter case, the debate between externalist and internalist views turns on whether the indiscernible infallible condition on knowl-edge should also entail some relevant discernible property. (I will briefly argue that it should not in sec. 4.4.1, though a full treatment of this debate is beyond the scope of this work.⁷²) I have no proof that a mixed inter-nalist account cannot be both genuinely conjunctive and avoid Gettier problems. But I think that, as a matter of fact, most internalist-inspired answers to the Gettier problem — notably, so-called “undefeasibility”

accounts — fall into either horn of the dilemma.

72. SeeBergmann(2006) for a recent and extended defence of the externalist view — though Bergmann frames the debate in terms of justification, not of knowledge.

2.5.5 The contemporary focus on justification

The fall of Ur-foundationalism also explains the contemporary focus of much epistemology onjustificationinstead of knowledge. In our view, the historical origin of the idea of justification is the notion of a discernible mark on the basis of which it is legitimate to assent to a proposition. On the Stoic view, the discernible marks that entitled one to assent were infal-lible, so there was no difference between justified belief and knowledge.

In the “probabilist” tradition initiated by Carneades, (qualified) assent was allowed on the basis of discernible but fallible marks. But these were not considered to be enough for knowledge. (Philosophers such as Locke adopted the first view for some domains and the second one for others.) Hume’s predicament shows that only the second way is open to the Ur-foundationalist.

The Justified True Belief analysis was an attempt to reconcile the idea that knowledge is a matter of discernible marks with the plausible view that we ordinarily know many things. Its failure, and the contemporary reluctance to give up common sense ground, made clear that knowledge and discernibility came apart. For those who were attached to the dis-cernibility element in Ur-foundationalism, knowledge started to lose its interest. Many focused on the putative discernible aspects of knowledge

— call them knowledge-level justification.⁷³ These properties were natu-rally grouped with the similar putatively discernible properties that are found in non-knowledge cases only, such has having statistical or weak evidence in favour of a proposition — call themlower-level justification.

The focus of justification — in its discernible sense — brings together philosophers of two stripes. One are the heirs of the “probabilist” tra-dition of Carneades, Peirce and Popper. They think that we have no knowledge. But rather than describing themselves as sceptics, they may argue for instance that the ordinary notion of knowledge is not relevant to

73. The most general discernible property of knowledge is the maximally specific discernible property, if any, that is instantiated in any case of knowledge. More specific discernible aspects of knowledge can be defined for subclasses of knowledge cases, e.g.

perceivingorseeing. Williamson’s (2000, ch.4–5) anti-luminosity arguments suggest that there is no non-trivial discernible property of knowledge. (See alsoWilliamson(2008).)

2.6. Conclusion 95