The role of fantasy is thus in a way homologous to that of the ill-fated pineal gland in Descartes' philosophy, this mediator between res cogitans and res extensa: fantasy mediates between the formal symbolic structure and the positivity of the objects we encounter in reality, i.e. it provides a 'scheme' according to which certain positive objects in reality can function as objects of desire, filling in the empty places opened up by the formal symbolic structure.