Karl Rosenkranz, philosopher of a prolific and encyclopedic knowledge and renowned biographer of Hegel, wrote a Psychology based on Hegel’s philosophy of subjective spirit. In this book he adopted and developed in his own way Hegel’s main concepts on the soul, consciousness, and spirit. The development of the work follows a dialectical method that starts from the most elementary form of insertion of the spirit in nature as a soul and its deployment, mainly as consciousness, self-consciousness, thought, and will. The chapter concludes by mentioning some critical remarks that have been made to this approach to psychology.