[Epistemic and historical elucidation of the borderline personality disorder]

The particularities of those that have been considered "hard cases" in the clinical field, and their relationship with personality disorders, are discussed together with their quintessential conceptual and diagnostic model: the borderline personalities. The aim of the study is to historically and epistemologically rebuild their origins within psychiatry and psychoanalysis.

From a classical epistemological and historical study, a brief tour is made through the nineteenth century alienism and the postulate of "partial insanity". Next, a passage is spawned through the concepts that emerged from this postulate: "monomania" and "moral insanity", up to mid-century Kraepelin and the "fundamental states" of manic-depressive insanity as pathological constitutional forms or characters, and reaching the twentieth century with characterology and psychopathic personalities. Finally, psychoanalysis is analyzed as the main source of borderline personality disorders arising from the problems encountered in analytical treatments and the development of the notion of "character neurosis".

Borderline personality disorders are the result of the conjunction of a number of factors, heirs of the notion of "partial insanity", of the fundamental states of manic-depression insanity, of characterology, of the idea of constitutions and pathological personalities, together with the emerging concerns of psychoanalysis in the early twentieth century.