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Notes
Schellenberg’s remark that “[a] subjectively indistinguishable perception will provide us with the very same phenomenal evidence” (12) suggests that if S and S′ are subjectively indistinguishable (or indiscriminable) sensory states then S and S′ provide the same phenomenal evidence. There is a familiar problem with this suggestion, given that subjective indistinguishability is non-transitive and sameness in such-and-such respect is transitive. Schellenberg should not be taken to endorse the suggestion, since she clearly rejects it elsewhere (forthcoming b, p. 27).
‘Based on’ is to be understood in the everyday sense in which, for example, Poirot’s belief/knowledge that Inglethorp is the murderer is based on evidence; no controversial account of “the basing relation” is being assumed.
More carefully, any non-factive explanandum (e.g. the subprime mortgage crisis) has a (contextually salient) factive counterpart, for instance the fact that the subprime mortgage crisis occurred; to explain the non-factive explanandum (in the context) is to explain the contextually salient factive counterpart. Cf. Williamson (2000), pp. 194–195 (Williamson is here arguing for the weaker claim that evidence is propositional, not that it is factive).
There is plenty of resistance to E = K, although less engagement with Williamson’s straightforward argument for it (2000, pp. 193–207). Another (quick) consideration in favor is this: evidence is the kind of thing that it is permissible to share. If P is part of my evidence, then in the course of collective inquiry it is permissible for me to share this piece of evidence by asserting it. But it is only permissible to assert P if one knows P (ch. 11).
The activity of justifying one’s beliefs (actions, decisions, salary,…) is familiar, but the literature sharply distinguishes this from having a justified belief, which is generally taken not to require the capacity to cite evidence or reasons (Alston 1985, p. 58; this paper also contains the classic exposition of the normative way of explaining ‘justified belief’, discussed two paragraphs below).
The relevant sense of ‘justified belief’ is doxastically justified belief. But a similar point holds for propositionally justified belief, what one is justified in believing. Canonical examples of this are precisely examples of beliefs for which one has evidence. Incidentally, it is apparent from the opening of Gettier’s paper that he takes the notions of being “justified in believing P” and of “having adequate evidence for P” (Chisholm’s version of the justification clause in the JTB analysis of knowledge) to be at least very similar, if not actually equivalent.
We may (harmlessly) grant that knowledge provides an exception. (This is not relevant to Hallie, since she lacks knowledge.) If knowing P entails justifiably believing P, then a case where one knows P not on the basis of evidence is a case of justified belief not based on evidence. And there is certainly some temptation to apply ‘justification’ to all instances of knowledge, even if the intended sense of ‘justified belief’ is explained by means of the canonical examples. But this is not of much significance: it may just reflect the fact that knowing is an epistemically excellent state, which strongly suggests an affirmative answer to the philosopher’s less-than-perfectly-clear question ‘Is the knower’s belief justified?’. (One could hardly say that the knower’s belief is unjustified.)
In this normative sense of ‘justification’, it straightforwardly applies to knowledge. Cf. note 7 above.
See Schellenberg forthcoming b, Sect. 3.1.
The corresponding paragraph in forthcoming b (16–17) is longer, but doesn’t appear to support the second premise any better.
We can just stipulate that this is true of Hallie, but it is quite unlikely to hold of hallucination in general. See, for instance, the description of Charles Bonnet syndrome in Sacks (2012, ch. 1).
Presumably Schellenberg does not mean that all one’s knowledge, no matter how distantly related to perception, counts as “factive perceptual evidence” (perhaps, though, it is supposed to count as factive evidence). This complication won’t matter for present purposes.
The third option appears to be the view that evidence consists of facts, but that one need not know a fact P in order for P to be part of one’s evidence; the second option is less clear, since Schellenberg does not explain the contrast between ‘propositional’ and ‘non-propositional’: if facts are true propositions, then this distinction presumably collapses.
See Goldman (1976, pp. 772–773).
A quick way of seeing that Schellenberg rejects the traditional view is to note her emphasis on the fact that Percy knows, not just that a white cup is on a desk, but that this white cup is on that desk. (See forthcoming b, esp. Sect. 3.2.) According to Schellenberg, Hallie has phenomenal evidence for the first proposition, but no phenomenal evidence for the second (or any similar singular proposition); since Percy has the same phenomenal evidence, he has no phenomenal evidence for the second either. Phenomenal evidence, then, is not part of the explanation of how Percy knows that this white cup is on that desk. And given this, there is an explanation of how Percy knows (or, at least, is in a position to know) that a white cup is on a desk that does not appeal to phenomenal evidence: Percy knows it by deduction from the singular premise that this white cup is on that desk.
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Acknowledgments
Thanks to the audience at the Oberlin conference; special thanks to Susanna Schellenberg and Susanna Siegel.
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Byrne, A. Perception and evidence. Philos Stud 170, 101–113 (2014). https://doi.org/10.1007/s11098-013-0170-2
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DOI: https://doi.org/10.1007/s11098-013-0170-2