Logics of delusion1

Delusion represents an exceptional test case for the principal categories of common sense and philosophical thought, such as ‘reason’, ‘truth ’ and ‘reality’. Via an engagement with the legacy of Freud and the most discussed results of twentieth-century psychiatry, my aim will be to analyse its paradoxical forms and to shed light on the logics that underlie and orient its specific modalities of temporalization, conceptualization and argumentation. Delusion, then, has traditionally been presented as synonymous with irrationality (absurdity, groundlessness, error, chaos), whereas by contrast its mirror image, reason, has been defined in terms of evidence, demonstrability, truth and order. I will analyse and contrast their paradoxical definitions. D