Ennead IV.6 [41]: On sense-perception and memory · 2

Sensation and memory, then, are not passivity but power.

And, once it is admitted that sensations are not impressions, the memory of a sensation cannot consist in the retention of an impression that was never made.

Yes: but if it is an active power of the mind, a fitness towards its particular purpose, why does it not come at once—and not with delay—to the recollection of its unchanging objects?

Simply because the power needs to be poised and prepared: in this it is only like all the others, which have to be readied for the task to which their power reaches, some operating very swiftly, others only after a certain self-concentration.

Quick memory does not in general go with quick wit: the two do not fall under the same mental faculty; runner and boxer are not often united in one person; the dominant idea differs from man to man.

Yet there could be nothing to prevent men of superior faculty from reading impressions on the mind; why should one thus gifted be incapable of what would be no more than a passive taking and holding?

That memory is a power of the Soul (not a capacity for taking imprint) is established at a stroke by the consideration that the soul is without magnitude.

And—one general reflection—it is not extraordinary that everything concerning soul should proceed in quite other ways than appears to people who either have never enquired, or have hastily adopted delusive ​analogies from the phenomena of sense, and persist in thinking of perception and remembrance in terms of characters inscribed on plates or tablets; the impossibilities that beset this theory escape those that make the soul incorporeal equally with those to whom it is corporeal.