Dialogues in Philosophy, Mental and Neuro Sciences

Existential a prioris are fundamental elements of the a priori structure of one's being-in-the-world (Dasein). They relate to Heidegger's existentials, although in psychiatry the analysis is mainly at the ontic level of concrete existence. The English term "existential" does not discriminate between the German "existenziell" and "existenzial". Here we mean with "existential" what in German is called "existenziell".
In this paper schizophrenic delusions and hallucinations are considered secondary phenomena, being founded in a primary alteration of the existential a prioris (the very "categories" that make possible the anchoring and orientation in the life-world).
In schizophrenia the alteration of the existential a prioris is recognized as a certain mode of being, different from ours, which is evident in the alteration of spatialization and temporalization, being-with others and bodily being (embodiment). This is discussed by the so-called technical delusions and hallucinations, which are psychotic symptoms experienced as being infl uenced by means of technical instruments. The recognition of the alteration of these basic pre-objective structures is very important for the understanding and therapy of people with schizophrenia.