In his youth anticlerical and rationalist, he “converted” at the beginning of 1832 to the theories of Saint-Simon (indeed he founded in Pisa, in his own home, a “church” of Saint-Simonians); he returned to Catholicism through the evangelical Christianity of Carlo Eynard (1843); he then became a fervent Neo-Guelph, while showing marked sympathy for the ideas of reform of Catholicism propounded by the Tuscan Catholic-liberal group; after the celebrated allocution of April 1848 by Pius IX, from the conviction that the pope could and should “harm no one,” he drew the consequence “of the incompatibility of spiritual power with the temporal power of the pope” (letter of 10 May 1848, in U. Mondello, Epistolario di G. M., dal 22 marzo al 29 maggio 1848, in Rassegna storica del Risorgimento, 24 [1937], p. 1337).
A man of courage, he fought at Curtatone with the Pisan university volunteers (in 1840 he had been appointed professor of civil and commercial law at the University of Pisa), receiving a wound. He advocated a national Constituent Assembly, in which there would be a clear separation of State from Church: on the question of the Constituent Assembly he changed his opinion several times, arriving, after Pius IX abandoned Rome, at envisaging a Tuscan-Roman Constituent Assembly under the presidency of Leopold II, in an anti-Piedmontese function; after the grand duke’s flight he became part of the Provisional Government with Guerrazzi and Mazzoni. The grand duke’s return found him on a mission in France, where he remained in exile. He returned to Italy after nearly a decade and voted for the deposition of the Lorraine dynasty. At first opposed to the passage of Tuscany under the Savoy, he later became a member of the Parliament of the Kingdom of Italy.
All the various shifts of M. (he had ended up, during his Parisian exile, as a “socialist” and a “Murattist”) were a symptom not of opportunism but of an unsettled and highly sensitive romantic personality.