Human destructiveness threatens survival. How is this related to instinct? Freud distinguished Eros from the instinct of the individual to die only in its own fashion, this appropriate-death instinct being turned outwardly as aggression, with instinctual energies interacting creatively or destructively.

The metamorphosis of instinct in the transition from one type of biological existence to another, from foetal placental parasite to baby is complicated by the delayed myelination of the nervous system. Transition from le corps morcelé to le corps propre coincides with paranoid-schizoid and depressive positions in the internal reality of the infant.