This text examines the historical and philosophical evolution of the relationship between the concepts of person and thing in Western tradition. It starts from the Greek understanding of thinking as a process of objectification, which influenced both Christianity and modern rationalism, leading to Descartes' definition of man as a thinking thing. The author traces the transformation of the subject through German Idealism to Kierkegaard, who emphasized the priority of interiority over external appearance. A significant portion is dedicated to the emergence of personalism and its key figures, such as Buber and Lévinas, as well as the anthropological shift in existentialism. The text critiques the separation of the subject from nature and, through the work of Teilhard de Chardin, proposes a new understanding of the natural unit. Subjectivity is not viewed as a human privilege but as a fundamental property of all entities, from atoms to living organisms. The subject is understood not as a static substance but as an event-based process in time. This approach allows personalism to overcome the limitations of naturalism and offer a deeper insight into the ontological nature of the world.