Toni Kannisto

Camilla Serck-Hanssen has used the concept of infinite judgment to expose a logical gap in the 2^nd Paralogism. I will explicate further why no future revision of this “Achilles” of rational psychology can succeed, for there is an inherent flaw in the procedure of rational psychology. By formalising the General Form of the paralogisms I pinpoint the logical gap and show that for rational psychology to succeed, the possible existence of soul must be demonstrated. Kant formulates this problem in modal terms: while the paralogistic inferences do establish necessary logical (analytic) truths about the idea of soul, they fail to provide necessary metaphysical (synthetic) truths about its object, the soul itself. For Kant, the latter requires application of the modal categories (possible, actual, and necessary existence), and the soul does not fulfill the criteria of possible existence. Ultimately the failure of rational psychology is that it cannot resolve the following dilemma: (1) If one starts with the rational idea of soul, one can prove apodictic analytic truths about it but cannot show that it refers to any possibly existing object; yet (2) if one starts with the empirically established existence of oneself, one cannot show that any of the predicates coveted by rational psychology pertain to it.