The theoretical work of Sigmund Freud contains multiple references to the topic of archaic inheritance and phylogeny. The aim of this paper is to analyze this aspect of his work, in order to point out the limitations of its most frequent interpretations, which tend to perceive the impact of Darwinism on Freud, or simply deny its relevance. We intend to prove that using phylogeny responded entirely to a clinical question regarding the etiology of neuroses.