The Latin equivalent of regression means "return" or "withdrawal"; it also signifies a retreat or a return to a less-evolved state. There is no very precise psychoanalytic definition of the concept of regression. It is useful to introducs the idea of temporality. It could be said to represent an articulation between the atemporality of the unconscious, the primary processes, and the temporality of the secondary processes. Some analysts assign this notion a metaphoric value; it retains the connotations of a journey through time and the changes that will be necessary in psychoanalytic treatment.