This text presents a critical examination of the relationship between the subject and its activity. The author challenges the common intuitive notion, rooted in collective experience, that a subject must necessarily precede its actions. It is argued that the subject is not a static entity but rather a structure that is transformed and re-established through every action it performs. It is only through this continuous process of integrating both itself and its activities that the subject maintains its persistence. The text draws upon Teilhard de Chardin’s concept of "centro-complexity" to explain the ability of natural units to integrate their essential nature. A key conclusion is that human action is never solely centrifugal, directed outward toward the external world, but always possesses a centripetal dimension as well. Every action thus simultaneously reacts back upon the actor, resulting in an internal transformation. Consequently, the subject is not merely the source of activity but also its product—a constantly evolving process of integration that changes its own internal structure through engagement with the world.