The Authority of Memory

[FIRST PARAGRAPHS] Nothing is more common than for us to continue to believe without rehearsing the reasons which led us to believe in the first place. It is hard to see how it could be otherwise. Were we obliged constantly to re-trace our cognitive steps, to reassure ourselves that we are entitled to our convictions, how could we ever move forward? We have probably forgotten why we adopted many of our current beliefs and even if we could dredge the evidence for them up from memory, we couldn't do this for more than a tiny subset of our beliefs at any one time. Since inquiry involves a reliance on many different beliefs, progress is possible only if we can use established results in future deliberation without re-fighting the battles of the past.[1] But this plausible thought appears to conflict with another, that we should believe only where we have adequate evidence: rational belief must be based on evidence for the proposition believed. Now one might quibble over what exactly 'have evidence' means. Is it required that whenever the belief comes to mind, so too does the evidence on which the belief is based? Or is it sufficient that one be capable of rehearsing this evidence? Either way, human beings are very often unable to satisfy this demand in respect of beliefs on which they happily rely. If this is illicit, inquiry must be reined in, constrained by our memory's inability to retain more than a fraction of the evidence relevant to the beliefs we formed at various points in the past. Epistemologists have responded to this tension in several ways. Externalists simply drop the demand that belief be based on reasons at all. Internalists try to find evidence on which rational memory belief might be based. There are two internalist strategies here. One claims that certain forms of empirical argument are generally available to underwrite the memory beliefs of the rational person, arguments which one can rehearse even if one can't recall the specific grounds on which one formed the belief in the first place. The other strategy simply asserts that memory beliefs have a prima facie authority, that one is entitled to rely on them without any justification, provided one has no grounds for doubting them. I agree with the internalist that we must have reasons for our convictions: to believe something is to believe it to be true and if you don't have any grounds for thinking it true, you shouldn't believe it. For example, information installed in our brains as part of our genetic endowment may exercise a beneficial influence on our behaviour but such evolutionary 'memory' is not a repository of knowledge: to make it such, we must have grounds for relying on it. Nevertheless, we must also get away from the radical internalist idea that having a reason to believe is a matter of being able, at the present moment, to produce evidence. One's belief may be well-grounded in past reasoning even if one is quite incapable of recapitulating that reasoning and there is no need to invent some alternative support for the belief which one can now bring to mind. We are not creatures of the moment, unable to carry our cognitive achievements forward from one instant to the next.