The purpose of this article is to show how schizophrenia, understood as a distortion of the most intimate structures of subjectivity, illustrates the nature of subjectivity as such, while at the same time how philosophical considerations may help to understand schizophrenia. More precisely, schizophrenic experiences of self-alienation seem to reflect a congealing or concretization of a form of differentiation or potential alterity implicit in the dynamic nature of subjectivity. In other words, we propose that the structure of subjectivity includes potential (...) divisions and fissures that condition the experiences of radical self-alienation seen in schizophrenia. In order to elucidate how this alterity emerges within the self in schizophrenia and in order to consider its conditions of possibility we examine the disorders of the self as described in phenomenological psychopathology. We especially use the work of the Japanese psychiatrists Mari Nagai, her teacher Bin Kimura, and the French psychiatrist Henry Ey, supplemented with clinical material from our own research. Finally, we shed light on the development of the psychotic symptoms such as hallucinations and delusions, which are understood as the expressions of a radical alterization of the self. (shrink)