The author addresses the essential aspects regarding the definition of the paternal function in metapsychological terms: how it forms and develops in the mental world, which functions it serves, or could come to serve, in the dynamic of mental functioning, and lastly, the consequent clinical implications, in particular the formation and development of symbolic capacity. In the second part, using two clinical vignettes and a clinical case, the author attempts to discuss its link to the theme of masculinity, suggesting a brief reflection on the challenges presented to the specificities of the analytical clinic.