ABSTRACT
This chapter explains how physiological reasoning and psychoanalytic reasoning, which a priori stem from incommensurate domains, come into direct connection in regard to homeostasis and unpleasure. According to psychoanalytic theory, a state of mental tension is associated with an unpleasure from which the person must be freed. Ultimately, the person is dealing with a perception, either a real one coming from external reality, or what Freud calls a hallucinatory one coming from internal reality. Thus the primary process by which the unconscious functions affects perception indirectly by mediating the action resulting from the discharge of drive excitation in accordance with the pleasure principle. The reality principle comes from what Freud calls the secondary process. In contrast to the primary process, it is based on contradiction; makes use of negation; acknowledges time and spatial differentiation; and, through the thought process formed by the activity of representation, allows for a suspension of discharge.
