Consistency Within Memories

It is impossible to prove an event happened in one's personal history by merely reflecting on a memory of that event, however genuine the memory may seem.  Just as the senses can perceive material objects that do not exist, memories might tell of events that never happened outside of one's mind.  This does not make memories any less real; recollections of past events are a part of reality all the same, just not in the sense that the events necessarily took place in the physical world.  Short of logical proof that one's memories correspond to actual events of the past, what is the best evidence that a recalled event truly did occur?

Consistency with reason and with itself is the minimum requirement for a thing to be true--although consistency alone does not make something true--and thus consistency is the first evidence that should be considered.  It is logically possible for memories that do not conflict with each other (that is, memories that are internally consistent with themselves and other memories) to correspond to actual events, but possibility is not utter confirmation.  Again, internal consistency is a necessary prerequisite to something being true, but this alone does not make memories accurate glimpses into past events.

Since memories of occurrences in the external world must reflect what has happened in the material plane in order to be accurate, the next requirement after logical consistency is evidence in the external world itself.  If one's memories not only do not contradict themselves, but also do not contradict any sensory information (perceived evidences in the external world), then there is greater evidence that they are in fact valid recollections of past events.  Evidence, on its own, proves only that evidence for something exists, but it is an integral part of probabilistic investigation.

Even if told of each of these logical facts, some might refuse to admit that a memory can be perfectly consistent with itself, with other memories, and with sensory perceptions and still not be accurate.  Memories of past events alone can only ultimately prove that the memories themselves exist within one's mind.  Although one can prove that, by logical necessity, the past has existed for at least a moment, there is not even a way to demonstrate that there was a past beyond that single moment.  At the same time, one can logically prove that one's memory does match itself and one's sensory environments with great ease.

Without this alignment of evidences, a conscious being would be adrift in complete confusion about perhaps everything except its immediate grasp of logic and comprehension of its thoughts and perceptions.  If a person is not experiencing such confusion, they can prove to themselves with absolute certainty that, at the very least, their memories are sound in the sense that they contain accurate information about their own mind and present sensory experiences.  Nonetheless, proving the legitimacy of perceptions is not the same as proving that recalled experiences happened as recalled--or that they happened at all.