This article focuses on Sartre's critique of theories of empathy in the third section of Being and Nothingness, in which the difficult issue of the existence of other selves is addressed. For Sartre, these theories appear inevitably destined to fail because they are too closely linked to an epistemological perspective in which the existence of the other remains as probable as the knowledge we have of them. This makes it necessary to reconfigure the relationship with otherness, shifting it from the plane of knowledge to the plane of existence. However, the Sartrian approach also has to deal with the problem of solipsism, which returns to the level of praxis, hindering the foundation of an authentic intersubjective relation