In this article, the authors propose to apply the language and methods of mathematical physics to the investigation and analysis of human psychology. More precisely, the article stems from the description of the human soul as a complex system. Consequently, it attempts at reframing the concept of soul in the perspective proposed by the KTAP (Kinetic Theory for Active Particles): this is a recently-developed phenomenological theory which has proved to be widely applicable to socio-economic and biological and behavioral issues.