Discussions about the foundations of psychiatry show repetitive traits. Although in the disputes that arise between the three main frames of reference (i.e. physical/naturalistic, hermeneuticphenomenological, and socio-critical) new ideas do emerge with regard to content, hardly any changes can be detected in the basic hypotheses. In this article this stalemate is analysed in terms of the fundamental ontological theories that lie at the root of the three perspectives. An attempt is made to drive the debate forwards by the introduction of the concept of ontological complexity. Eventually it is argued that existential and moral learning processes of the psychiatrist (and in the environment of their patients) are just as important for their profession as are empirical and analytical insights, measurement scales and methods and innumerable pharmacological aids.