The entire range of emotional stirrings, aggression, defense, sacrifice, mourning, melancholia, ecstasy, triumph, et cetera, is expressed through the revival of movements, gestures, and postures, that is pathosformel: the expressive formulas of emotion either taken from ancient modes or reappearing as mnemonic traces in successive works.

Original source for this? (Likely in German as original.)

Warburg is talking about the expression of current art through the lens of the classical arts and there is a throughline of "mnemonic traces" through out time.