x = An event, an image (sensu latissimo) of which you have in yer mind.

  1. x is memory only if x is a past event
  2. x is a past event only if x is a memory

The criterion for x being a memory (and not, inter alia, an imagination) is that x is a past event.

The criterion that x is a past event is that x is a memory (and not, inter alia, an imagination).

The loop problem: You can't know x is a memory unless you know x is a past event BUT you can't know x is a past event unless you know x is a memory. That is to say you can't know either.

Given any x, you can't differentiate between x is a memory i.e. x is a past event and x is a figment of yer imagination.

How do we exit the loop?

  • 2
    The problem seems that the loop requires 2 stand on its own as a coherent statement of fact, but it doesn't. An event can occur in the past regardess of whether it is remembered or imagined. May 6, 2023 at 12:52
  • @Futilitarian, that is correct! Metaphysically that's something I can't rule out ... at least not yet. May 6, 2023 at 15:06
  • Upon reflection, maybe 'occur in the past' is mistaken language; an oxymoron. 'Occur' is present. 'Past' is past. Maybe I should say 'an event can have occurred in the past, regardless of whether it is remembered or imagined'. May 6, 2023 at 15:27
  • @Futilitarian I suppose you're right and in fact the question revolves around whether x (a mental image) is a record of the past or just an imagination (x could've occurred in the past). We don't know. May 6, 2023 at 15:31
  • 1
    @AgentSmith X can be a past event without being a memory. Say, it just happened some days ago and no information about it reached you. So, you don't have the memory of X even when it is a past event.
    – user65403
    May 6, 2023 at 16:01

4 Answers 4


A few points. One, even if it were a loop, there is no reason to go round it. Two, x can be a past event without being a memory. Three, memories can be checked against other evidence. I know this from regular personal experiences. For example, x might be my leaving my wallet in the car five minutes ago, of which I have no memory. I can confirm x by patting my pockets and finding them empty. No loop there.

  • An ingenious half-solution! Kudos! Go on ... May 6, 2023 at 15:05
  • 1
    A past event is not necessarily memory.
    – user65403
    May 6, 2023 at 16:03
  • 1
    I've had dreams about places I later visited for the first time.
    – Scott Rowe
    May 6, 2023 at 22:35

My memory of the event and the event itself are two separate things, and they are notably different in that the event and my memory of the event do not happen at the same time.

Suppose, X is an event that happened 2 days earlier. When you remember X, you are remembering X now, not 2 days earlier. What qualifies X to be a past event is that it happened 2 days earlier, regardless of if you remember it or not or when you remember it. What qualifies X to be a past memory is your memory of the event. Since you can remember things that aren't past events (Mandela effect for example), and forget actual past events, both premises are wrong.

  • I can't say I disagree and missing the point is, mirabile dictu, seeing another point! May 20, 2023 at 11:52

Information here:, derived from logic:

  • If there was a past event, there is a memory.

  • If there was no past event, there is no memory.

  • If there is a memory, there is a past event.

  • If there is no memory, there is no past event.

This doesn't create a loop of uncertainty at all, any conditions converge and stay in their own loop, which doesn't need to be further traversed.

You stated that X is a memory only if X was a past event. The second statement need not be considered; it is true, but doesn't contribute to uncertainty, because it is mutually exclusive.

Given the circumstances, imagination is impossible! X is a memory ONLY if x is a past event.

Given a memory, the past event occured, and given a past event occured, it is a memory. No Alzheimer's needed.

  • Danke for your response. The Macro Orcam solution (👍👍👍). He and you, together, offer me a glimpse of Deus; although tainted, I'm just glad, really, really glad. May 20, 2023 at 11:50

There are two kinds of images I have in my mind:

  • images that I intentionally assemble
  • images that assemble themselves

I know the latter are past events because I always see images that assemble themselves in my mind as I have experiences. I never have images that I make up through intentional assembly which thereafter always assemble themselves. I can directly differentiate the two because I am directly aware of whether my intent is involved with the assembly of an image.

  • Good shot! A few wrinkles ta iron out and we might just have a winner! May 20, 2023 at 11:44
  • @AgentSmith what wrinkles do you propose I iron out?
    – yters
    May 21, 2023 at 16:22
  • Well, if you aren't stating tautologies, what I'm referring to should be clear. May 22, 2023 at 2:28
  • Oh I see, you are saying my answer is tautological, because I am referring to memories as justification for distinguishing memories from past events.
    – yters
    May 22, 2023 at 14:34
  • if [you aren't ...] May 22, 2023 at 16:07

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