According to the standard view, the causal process connecting a past representation and its subsequent recall involves intermediary memory traces. Yet Bertrand Russell and Ludwig Wittgenstein held that since the physiological evidence for memory traces isn't quite conclusive, it is prudent to come up with an account of memory causation-referred to as nmemic causation—that manages without the stipulation of memory traces. Given mnemic causation, a past representation is directly causally active over a temporal distance. I argue that the stipulation of memory traces is indeed indispensable for analyzing mernory causation.