He engaged with manifold themes, but he devoted special attention to the interpretation of the socio-economic problems of interior areas of Sardinia, which he discussed according to his own ethical and political views.
Antonio, whose father had died in the meantime, left his town after school to move to Sassari with his maternal grandparents, to complete his classical studies training.
From 1956 Pigliaru decided to give a different style to the journal, focussing its contents on the so-called 'Sardinian issue' (Questione sarda): the editorials, written by him, were often devoted to the region's problems.
Pigliaru died on 27 March 1969 in Sassari, during a haemodialysis session, a therapy he regularly undertook to cure his grave kidney deficiency, a condition that had affected him for most of his life.
After an initial approach to Giovanni Gentile's philosophy, especially in his first works "Considerazioni critiche su alcuni aspetti del personalismo comunitario" and "Persona umana ed ordinamento giuridico," he leaned towards Giuseppe Capograssi's historicist personalism.
He subsequently developed questions of Gramscian Marxism, especially in his "Struttura, soprastruttura e lotta per il diritto", "Gramsci e la cultura sarda" and in the unfinished essay on "L'estinzione dello Stato".
Among his several contributions the following are noteworthy: "Meditazioni sul regime penitenziario italiano" (1959); "La piazza e lo Stato" (1961); "Promemoria sull'obiezione di coscienza" (1968).