This is an original preprint of an article published in The International Journal of Psychoanalysis on 17 Apr 2020, available online: hps://www.tandfonline.com/doi/full/10.1080/00207578.2020.1726713 . The supplement of this version has not been published yet. The bringing together of elements that have apparently no connecon in fact or in logic in such a way that their connecon is displayed and an unsuspected coherence revealed…is characterisc of Ps↔D [the paranoid-schizoid and depressive posions interplay] (Bion 1989) On the Logic of the Unconscious/ Amit Saad Abstract Freud argues that the laws of classical logic do not hold true with regard to the unconscious. The aim of this paper is to provide an alternave logic that is consistent with Freud’s concepon of the unconscious. This aim is achieved in two steps. First, I argue that most Freudian features of the unconscious are consequences of the fact that unconscious thoughts in the Freudian sense are negaonless. Then I suggest a formal logical system that lacks the negaon symbol, and is known as negaonless-logic, with which to formulate the logic of the unconscious. I demonstrate that this suggeson provides a beer understanding of various psychological phenomena, such as projecon, reacon-formaon, delusion, and the misconstrual of the empty set in childhood. Finally, I argue that negaonless-logic provides soluons to certain shortcomings in Mae-Blanco’s formulaon of the logic of the unconscious. 1. Introducon Psychological accounts typically include proposions such as John thinks that apples are tasty, or Jane wished that she would get the job. The general form of such proposions is: (*) A thinks/believes/wishes/hopes etc. that p. where A is a subject and p is a proposion. Usually we jusfy such claims based on observaons of the subject’s behaviour and uerances (Denne 1989; Hacker 1990; Wigenstein 1953). For example, if John prefers apples over bananas, it would usually be jusfied to assert that John thinks that apples are taser than bananas. Before Freud, it was assumed that a claim like (*) enjoys first-person authority, i.e. 1