Second son of the philosopher Giovanni and Erminia Nudi, he graduated in 1925 from the University of Rome with a thesis on Blaise Pascal which two years later, rewritten after a period of study in Paris, was published by Laterza.
In September 1932 his father took control of the Sansoni publishing house in Florence (later becoming its sole owner in 1935) and entrusted it to Federico Gentile, together with his younger brother Fortunato, helped by other prominent authors and collaborators, based on the model of the Enciclopedia Italiana: Ruggero Bonghi, Alessandro D'Ancona, Robert Davidsohn, Ferdinando Martini, Ernesto Parodi, Ermenegildo Pistelli, Pio Rajna, Francesco Torraca, Georg Voigt and others.
With him the number of published works increased, although it collapsed in 1945 following the war and the dramatic events of 1944 that led to the violent death of his father, the philosopher, who remained loyal to fascism.
In 1945, however, the Parri government allowed him to regain control of Sansoni, and little by little other authors such as Migliorini, Devoto, Omodeo, Longhi, Salmi, Calogero, Saitta, Praz, Russo, Contini, Bausani and many others were added.
The company also publishes the annual bulletins of the Accademia della Crusca, and has series on philosophy, linguistics, narrative, and poetry.