The movements and protests of 1968 worldwide criticized the traditional idea of normality. From the 1970s onwards, psychiatry and antipsychiatry became an ideological battleground centered on the boundaries between normality and madness. In this scenario, characterized by a deep cultural and political transformation within the Left, the traditional concept of rationality and its very connection with irrationality was called into question. As a consequence, the very ideal of reason was questioned. This paper will explore the debate on rationality, irrationality and (...) irrationalism within the so-called anti-institutional psychiatry and its reception in the Italian New Left during the second half of the 1970s. (shrink)