Psychiatric diagnostic systems contain approximately 400 mainly descriptively defined categories with incomprehensible overlaps and comorbidity. Empirical research has demonstrated a multitude of biological, psychological, and social risk factors, which are, however, not integrated in any conceptually coherent pathogenetic model. We argue that over and above a purely superficial symptomatic description we should address the level of mental structures underlying the symptoms. We emphasize the basic ontological structures, which are conditions for human experience and existence: intentionality, selfhood, intersubjectivity, temporality, and embodiment. A structural level may serve the purposes of classification and provide an integrative bridge between biological and psychological phenomena. We concentrate upon the level of selfhood where we distinguish the structural features (the so-called core self) and the more personal language and history involving level (the ‘narrative self’). Through a review of literature and presentation of two clinical cases, we demonstrate the value of the concept in studying schizophrenia.