22 May 2010

I am currently writing on the following skeptical paradox:

(1) A belief is (epistemically) reasonable only if one has good, presently-available evidence for it.
(2) We have no good, presently-available for most of the things we recollect.
(3) Therefore, most of our recollections are not (epistemically) reasonable.

I call this the paradox of absent evidence.

The point of epistemic reasonability is that it is aimed at true beliefs and not, say, at beliefs that are pleasant, practical, prudent, et cetera. It might be prudent to believe a proposition for which one has no evidence but it would not, at least if (1) is true, be epistemically rational to believe it.

It seems that (1) and (2) are true and that (3) must be true if (1) and (2) are. So where is the mistake? Or should we just accept skepticism about memory?


  1. I can think of several ways to weaken (1) and avoid the paradox as stated:

    (1') A belief is (epistemically) reasonable only if *either* one has good, presently-available evidence for it *or one could have good evidence for it.*

    The plausibility of (1') then depends on what "could" means.

    To get at the next alternative, I need to construct a model. Let a model-person be a model of an actual person from which one abstracts limitations based upon finite dispositions (such as a person's limited memory capacity). The literature on meaning skepticism is full of models like this (on which, see my forthcoming paper in EJP). Then consider

    (1'') A belief is (epistemically) reasonable only if *either* one has good, presently-available evidence for it *or an ideal model of oneself would have good, presently-available evidence for it were the ideal model to have acquired the belief in the same way oneself actually acquired the belief.*

    Since, by construction, the ideal model does not suffer from memory limitations and has, in fact, a capacity for perfect recollection, the ideal model retains the capacity to recollect evidence acquired in the past in a way that an actual person does not.

    George Pappas has a paper about ongoing knowledge in Synthese (1983), and somewhere I have a paper of his on a general problem of missing evidence (can't recall the reference, but I'll look for it).

  2. I guess my question is simpler. I don't exactly see why we even should accept 1 as true. Why do we have to have presently-available evidence for a belief to be reasonable? Related question: what is the standard of reasonable here?

  3. A better response:

    Funning things occur to one while mowing the lawn. I think what I mean to say in asking the question above is something like this:

    I think the argument should be reversed. The fact that we rely on memory for virtually everything (about this, see below) seems to me to show that we should reject premise 1 and its standard of reasonability as unreasonable. What the skeptical argument shows is that the idea that epistemically reasonable beliefs are only those for which we have presently-available evidence must be rejected in favor of the testimony of our memory.

    The problem with the standard of presently-available is that the present tends inevitably to collapse in on itself. Does the evidence that I need have to be IMMEDIATELY present, or just "temporally nearby" -- and if it's just nearby, how nearby is reasonable? I don't think that even my most immediate perceptions are immediate enough to count as absolutely present to me. So, depending on how the terms "memory" and "present" are meant in the paradox, it seems that we may never have evidence that is present enough, or that memory is always playing a role in providing evidence.

  4. It is like trying to predict the movement of a chaotic system when deciding if it is choice or fate that determines one's sexuality. Sexuality is something that depends on life experiences, on life experienced by your parents, on the life experiences of everyone you've ever had a connection with sexually or otherwise, implicitly or explicitly. These things cannot be quantified or controlled, they are random. How do we make a decision on fate vs. choice when something is so chaotic? It seems impossible. I'm absolutely not meaning to say it is impossible, it just seems that way.

    As a young person, navigating in a world of politics, opinion, religion, what I see as hate and others see as moral conviction, it seems the only way a politician would change their homophobic view point is for someone they really respect to tell them they are wrong to believe such things, for them to agree to be enlightened. As a person who cannot define sexuality even for myself I am forced to accept that others seek to define me as making a choice, as being born this way; they seek to define something undefinable. They define things relative to their self.

    We know what happens when one defines something in an absolute sense relative to their self in nature, they encounter contradictions, failure, limits are reached, new models must be defined. I think humanity is approaching a revolution in the way we think about sexual orientation. This is a topic that my grandmother probably could not be able to wrap her mind around. It seems inevitable that one day, humans will be scoffing at the old belief system the majority of people hold today on orientation, they will be saying things like "how could people think like that, those arguments and beliefs were obviously flawed, If I lived then, I hope I wouldn't be so ignorant!", at least that is what I hope.