The author questions the pertinence of using hope and hopefulness indifferently, showing how hope can often be a defence and, conversely, how hopefulness can be a paradoxical experience at the heart of despair. We can thus contrast those who are manifestly driven to despair and those who are inveterately hopeful, whose evolution is sometimes inverted. The work of mourning is revisited, while insisting, more than usual, on its vicissitudes. This leads to questioning anew Freudian metapsychology, particularly its version with deterministic accents: we are then obliged to consider other models arising from non-Newtonian sciences.

Randomness, thus taken into account, redefines the place of a certain freedom in the singular encounter between patient and psychoanalyst.