6 ideas
Memory is not perception of the present or expectation of the future but the possession of an image taken as a likeness of something past. What makes an image a memory rather than mere imagination is that it is apprehended together with the sense that time has elapsed since the original perception. Only animals that perceive time can therefore remember.
A painted animal can be contemplated as a picture in itself or as a likeness of a real individual, and a mental image works the same way. Viewed on its own it is a mere phantasm or thought, but viewed as a copy of something previously perceived it becomes a memory. Errors arise when people take a bare image for a likeness, or a likeness for a bare image.
Perception stamps an impression on the soul-bearing body the way a signet ring presses into wax, and the memory is the enduring trace. Its fidelity depends on the material's condition. The very young and very old remember poorly because their bodies are in flux, too fluid or too hard to take or hold the stamp, and the very quick or very slow are similarly impaired.
Recollection is not relearning or re-perceiving but actively recovering a prior state by moving through a sequence of mental movements. Because movements follow each other by habit, arousing one tends to trigger the next, so the recollector hunts for a starting point that leads to the target. Links run by similarity, contrast, and contiguity.
The most efficient way to recollect is to begin from the start of a sequence or from a central point from which many chains branch. Ordered material such as mathematical proofs is easier to recover than disordered material because each step reliably cues the next. If one route fails, the searcher goes back to the hub and takes a different branch.
Many animals remember, but only humans recollect, because recollection is a kind of inference: searching, testing, and concluding from one thing to another. It is also bodily. Once the search is set in motion it can run on uncontrollably, which explains why a name we have stopped hunting for can surface later and why melancholics are especially disturbed by lingering images.