This work offers a systematic rereading of Gilbert Simondon's philosophical project, arguingthat psychology constitutes the genetic and methodological core of his thought rather than a secondary concern.Beginning with a comparative analysis of Simondon's two doctoral theses (L'individuation à la lumière des notionsde forme et d'information and Du mode d'existence des objets techniques), the study traces the profoundinterconnection between individuation, technique, and nature, situating Simondon's encyclopaedic approach indialogue with Norbert Wiener's cybernetics and the theory of complex systems. Drawing on lesser-knowncollected texts — course transcripts, lectures, and interviews spanning the 1950s to the 1980s — the researchreconstructs the evolution of Simondon's thought and its entanglement with psychology, sociology, and thephilosophy of nature. Central to the argument is the role of psychic individuation as the hinge between living andcollective individuation, with affectivity and perception identified as the structuring forces that enable theindividual's ongoing relation to the pre-individual and to transindividuality. The study further examinesSimondon's 1965–66 course on imagination and invention, illuminating its connections to both ILFI and MEOT. Aconcluding critical survey of the secondary literature since 1989 foregrounds the affective turn in recentSimondonian scholarship and opens towards the relevance of his framework for reflecting on contemporarydigital technologies.