There are two important scientific statements that Aristotle makes about memory: First, the elementary unit of memory is a sense image, and, second, associations and links between memories serve as the basis for higher-level cognition. The text uses the names memory for the elementary unit and recollection for reasoning by association with elementary units.

It is striking to see how much emphasis Aristotle places on the sensory qualities of memory. He sees memories as belonging “to the perceptual part” and believes that “memory involves an image in the soul, which is among other things, a sort of imprint in the body of a former sense image.” Memory, specifically, does not consist of abstractions.

Appropriately Aristotle comes up with a remarkably vivid visual image to express this: “For the change that occurs marks in a sort of imprint, as it were, of the sense image, as people do who seal things with signet rings.”