Matt McGrath sent me a note about memory that got me thinking a bit about it. I’ve never worked on memory, and haven’t checked the literature to see if this issue has been discussed, so this may already be out there. The bottom line point is that there seem to be at least two quite different kinds of memorial beliefs, and the distinction between the two threatens assumptions many, including me, have made about such beliefs.
Ask me how to get from the house I grew up in to the church we attended when I was young, and memory becomes active. I remember the street I lived on, I imagine travelling from that street, across the railroad tracks to Main Street, turning left, going 3 blocks and turning into the parking lot of the church. So now I have a belief that, even if it was present prior to this incident, is now based on the activity of memory just used in reconstructing the route.
There’s a different role for memory, however, that does not involve such activity. Take a belief originally formed on some basis–say, perception–and in the ordinary case, the belief will be retained across time. A week later, one will often still believe that there is a tree in one’s backyard, for example. Is this belief a purely perceptual one? It started out as one, but the retention of the belief seems quite clearly a function of something further–namely, the operation of memory. The belief began by the operation of perception, and continued to exist, we might say, in virtue of the operation of memory: after being formed, the belief is retained in memory, and thus it is a mistake, a week later, to call the retained belief a purely perceptual one.
So one kind of memorial belief is where the belief is based on the activity of memory itself, and another kind is where the belief is simply retained in memory but is not based on any activity of that faculty or power.
This raises the question of whether one kind of memorial belief can be explained in terms of the other, or if we are stuck needing two kinds of epistemic principles in order to account for the (doxastic) justification of memorial beliefs. More important, though, is the issue of the justification of belief retention in memory. If basing is causal, then the basis of such beliefs would seem to remain whatever prompted the belief in the first place (at least, there won’t be an evidential state that is memorial in character that sustains the belief in existence). If basing is explanatory, then memory might play a role here, but it won’t play a role in virtue of there being some state of recollection or recalling that matches, or is appropriately related to, the content of the belief state. So not only is there a question about what the evidence is for such a belief, there is also the question of what such a belief is based on.