Following the publication of the first essays on Scheler and Leopardi, and after having started teaching in the Tuscan high schools, he was called by Giovanni Gentile in 1939 to cover the role of German lecturer at the Scuola Normale Superiore in Pisa, where he remained until the end of the war.

[1] In the Thirties and Forties, Luporini was one of the representatives of Italian existentialism, with a reflection focused on the freedom of the individual.

With Ranuccio Bianchi Bandinelli and Romano Bilenchi he founded in Florence, in 1945, the cultural magazine Società.

Among the parliamentary initiatives, he is co-signer, together with Ambrogio Donini, of the draft law (n.359, 21 January 1959) for an organic reform of the lower secondary school, considered a fundamental step for the democratization of civil life.

During the tough political confrontation that in 1989 led to the dissolution of the PCI and the formation of the PDS, he sided with Pietro Ingrao against the "turning point" of Achille Occhetto, for the defense and revival of the Communist Refoundation.