Memory trace was originally a philosophical term used to explain the phenomenon of remembering. Once debated by Plato, Aristotle, and Zeno of Citium, the notion seems more recently to have become the exclusive province of cognitive psychologists and neuroscientists. Nonetheless, this modern appropriation should not deter philosophers from thinking carefully about the nature of memory traces. On the contrary, scientific research on the nature of memory traces can rekindle philosopher's interest on this notion. With that general aim in mind, the (...) present paper has three specific goals. First, it attempts to chart the most relevant philosophical views on the nature of memory traces from both a thematic and historical perspective. Second, it reviews critical findings in the psychology and the neuroscience of memory traces. Finally, it explains how such results lend support to or discredit specific philosophical positions on the nature of memory traces. This paper also touches upon the issues raised by recent empirical research that theories of memory traces need to accommodate in order to succeed. (shrink)