The central argument of On Being Normal and Other Disorders is that psychic identity is acquired through one’s primary intersubjective relationships. Thus, the diagnosis of potential pathologies must also be founded on this relation. Given that the efficacy of all forms of treatment depends upon the therapeutic relation, a diagnostic of this sort has wide-ranging applications. The author’s critical evaluation of the contemporary DSM-diagnostic shows that the lack of reference to and governing metapsychology impinges on the therapeutic value of the DSM categories. In response to this problem, the author sketches out the foundations of such a metapsychology by combining a Freudo-Lacanian approach with contemporary empirical research. Close attention is paid to the processes of identity acquisition to show how the self and the Other are not two separate entities. Rather, subject formation is seen as a process in which both the subject’s and the Other’s identity, as well as the relationship between them, comes into being.