This text aims to explain why «anthropological monism» is the most adequate perspective in order to understand human reality, and that this ‘monism’ must not be necessarily considered as materialist. I will divide my work in four sections. First, I will explain briefly the Cartesian paradigm and what I consider some of its ontological mistakes. Then, I will try to build a phenomenology of the self with Edith Stein’s anthropology as its base, in order to reunite the two realities separated by Descartes: body and subjectivity. Third, I will talk about the concept of ‘form’ as the inseparable vital principle of living beings and, finally, I will talk about empathy as the phenomenon by which we constitute the idea of ‘I’ and the notion of ‘human being’. This way, monism will be presented as the best option to explain human reality and its activity