The aim of this treatise is to focus on Plotinus' Ennead IV to investigate his theory of the soul, by means of which this interpretation of memory has been acquired. The paper begins by using his notions of the soul to examine his idea of the relationship between sympathy (sympatheia) and affection (pathos), which are fundamental to his theory of memory and recollection. In his theory of sympathy he proposes a concept of "common" (koinon) to explain common affection (homopatheia), arising from the soul and its objects, and which provides the means for us to understand external objects, thereby being able to distinguish the memory of perceived things from that of reasoning.