Organization Italian Socialist Party

American Academy of Arts and Letters (Foreign Honorary ∙ Literature ∙ 1950)

Italian Communist Party

Office of Strategic Services

Congress for Cultural Freedom

National Institute of Arts and Letters

PEN

Italian Pen Club (president)

Association for the Freedom of Italian Culture (chairman)

Avanti! (editor)

L’Espresso (cofounder)

Italian Radical Party (founding member)

La Repubblica (cofounder)