In his paper, the author reviews the various psychoanalytical theories of the infantile sphere, starting with Freud's early work. He raises the question of the centrality of sexuality and aggression as Freud conceived them as instinctual drives, and therefore as innate dispositions. He stresses the importance of environmental influences and trauma in psychic development. Drawing on the perspectives of Freud, Klein and Laplanche, he examines the different visions of infantile sexuality and the drives, while highlighting the limits of generalizations produced retrospectively based on adult patients. He argues in favour of a more flexible approach, integrating different perspectives that are open to contributions from contemporary science and adjacent disciplines. He considers that the reflexive resources of psychoanalysis enable him to renew his practice by taking better account of the complexity of the human mind.