Lotta Continua
In June 1971 he was one of the 800 intellectuals who signed, in L'Espresso magazine, a manifesto against Luigi Calabresi, a police officer falsely suspected of having killed the anarchist Giuseppe Pinelli. In October he was among those who signed a "self-denunciation", to express solidarity with some journalists of "Lotta Continua" newspaper, defending their strong anti-government positions.