Karl Jaspers published the first edition of 'General Psychopathology' in 1913. Now, coinciding with its 100th anniversary whose importance was consecrated through multiple congresses, we see a parallelism and a return to the dilemma of the 'Methodenstreit', which led Karl Jaspers to introduce the phenomenological method for psychopathology to understand the subjective manifestations of the mind. Phenomenology is part of the research and clinical methods in psychiatry and psychology as a way to capture the subjective in psychopathology. However, phenomenology is nowadays wrongly used. In this article, we attempt to rediscover and present in a clear way the origins and meaning of Jaspers' phenomenology, whose bases, although forgotten, remain current. This will be done by revising its fundamental concepts such as objective and subjective manifestations, understanding and its four types, causal explanation, empathy, intuition, presuppositions and preconceptions, phenomenological description and comprehensive 'seeing'.
Keywords: Jaspers; phenomenology; psychiatry; psychology; psychopathology.