Saturday, July 23, 2011

Fitting the Evidence

I've never been at all sure what to make of 'evidentialism' in epistemology. Following is a fairly naive response to Conee and Feldman; I suspect there's some discussion of these or closely related issues; I'd be happy to be pointed to them.

Conee and Feldman think that the doxastic attitude I'm justified in having toward any given proposition is the one that fits my evidence. However, it's just not at all clear what that's supposed to mean. They offer examples, by way of illustration:
Here are three examples that illustrate the application of this notion of justification. First, when a physiologically normal person under ordinary circumstances looks at a plush green lawn that is directly in front of him in broad daylight, believing that there is something green before him is the attitude toward this proposition that fits his evidence. That is why the belief is epistemically justified. Second, suspension of judgment is the fitting attitude for each of us toward the proposition that an even number of ducks exists, since our evidence makes it equally likely that the number is odd. Neither belief nor disbelief is epistemically justified when our evidence is equally balanced. And third, when it comes to the proposition that sugar is sour, our gustatory experience makes disbelief the fitting attitude. Such experiential evidence epistemically justifies disbelief.

My problem here isn't that anything strikes me as false -- it's just that I don't see that justification has been illuminated by the connection to 'fitting the evidence'. I don't feel like I have a better antecedent grip on what the evidence is, and how to tell what fits it, than I do on what is justified. Conee and Feldman go on to observe that various views about justification are inconsistent with evidentialism, because, e.g., they have the implication that only a responsibly formed belief is justified, but some beliefs that are not responsibly formed fit the evidence. One needn't think this, though; perhaps what fits the evidence is what one would do if responsible. Or, certain reliabilist views will have the implication that Bonjour's clairvoyant character has justified beliefs; this too can be rendered consistent with the letter of evidentialism by allowing that external facts about reliability play a role in what evidence one has (or, less plausibly, which attitude fits a given body of evidence). A commitment to evidentialism per se doesn't seem to tell you much.

A theory of justification, it seems, ought to be illuminating, in the sense that it should explain justification in terms of states and relations that are antecedently well-understood. (As indicated last post, however, I don't think this constraint implies that the stuff on the right-hand-side need always be non-epistemic.)


  1. I don’t know much about philosophical discussions about evidence, but I suspect that there are some who think that Bayesian Confirmation Theory has been enormously helpful in increasing our understanding of evidence. According to some, whether or not E is evidence for hypothesis H is determined by whether or not P(H/E) > P(H). That requires some judgment as to the prior probability of H. Presumably our prior probability assignments to H must be justified. But they cannot be justified by the evidence in question (E, that is) precisely because we are dealing with prior probabilities. So I wonder how evidentialists would think about justification with respect to our subjective prior probability assignments.

  2. Hi Jonathan,
    There are lots of platitudinous sounding claims about j and e that I find in their work and never do I find these claims terribly helpful. Still, I think they are probably false. For example, compare three claims: (a) you may believe what fits the evidence
    (b) you must not believe without sufficient evidence
    (c) you must not believe without sufficient reason
    Of these three the last seems most obvious. I would argue that whether there is suff reason depends both on reasons to believe and reasons not to believe. If reasons-not do not supervene upon a subject's evidence, we can accept c and b while rejecting a. Take the view on which you shouldn't believe p if you cannot properly treat p as a reason for action or for belief. If p isn't properly included in deliberation, there is not sufficient reason to believe but the belief might fit the evidence. I take it that c and f either have to reject c or reject the idea that there are any epistemic norms of the sort I'm imagining that govern belief ( norms the satisfaction of which depend upon more than just relations of fit). Once this is clear, I think it is fair to ask why we should prefer their apparent platitude a to c.

  3. Just saw this. I think the key to your puzzlement, Jonathan, is etiological. They never took it to be illuminating apart from a theory of evidence. They were just taken aback that people were fairly nonchalantly offering responsibilist cases which had pretty clear evidentialist answers, which struck them as much simpler. They are amazed that people found the thesis controversial. They've made pretty clear what they take their theory of evidence to be and the view that's supposed to be illuminating is the wider view, though they acknowledge that one wants a theory of epistemic support as well--which they also offer, and then they also would like to put it to work, in a theory of knowledge, which at least Rich does. The Rochester way is to really labor over the small stuff, the foundations, etc. We used to spend whole seminars on the opening words of an essay. Often, Earl would contemplate the title for some time. I persist in being amazed that people are still offering the same kinds of responsibilist cases as counter-examples to evidentialism. If you're really interested in the topic, I do have a suggestion... :-)