Felice Balbo’s philosophy developed over a brief period, from 1945 to 1964. In this period, a discontinuity can be noted in 1949, when, in dialogue with Augusto Del Noce and Norberto Bobbio, Balbo began to develop a philosophy of being. This philosophy was already present in his earlier works (L’uomo senza miti and Il laboratorio dell’uomo), but in Idee per una filosofia dello sviluppo umano (1962) and in the posthumous fragments of Essere e progresso (1964), it found expression in two concepts from Thomas Aquinas’s philosophy, those of ens participatum and actus essendi. The article aims to discuss the reasons for the shift from a philosophy of praxis to a philosophy of being and to analyze the structure of Balbo’s final philosophy.