to repeat is an effort to restore a state that is both historically primitive and marked by the total draining of energy: death. Such an explanation has been described by some scholars as "metaphysical biology". Melancholia In his 1917 essay "Mourning and Melancholia", Freud distinguished mourning, painful but an inevitable part of life, and "melancholia", his term for pathological refusal of a mourner to "decathect" from the lost one. Freud claimed that, in normal mourning, the ego was responsible for narcissistically detaching the libido from the lost one as a means of self-preservation, but that in "melancholia", prior ambivalence towards the lost one prevents this from occurring. Suicide, Freud hypothesized, could result in extreme cases, when unconscious feelings of conflict became directed against the mourner's own ego. Femininity and female sexuality Freud's account of femininity is grounded in his theory of psychic development as it traces the uneven transition from the earliest stages of infantile and childhood sexuality, characterised by polymorphous perversity and a bisexual disposition, through to the fantasy scenarios and rivalrous identifications of the Oedipus complex and on to the greater or lesser extent these are modified in adult sexuality. There are different trajectories for the boy and the girl which arise as effects of the castration complex. Anatomical difference, the possession of a penis, induces castration anxiety for the boy whereas the girl experiences a sense of deprivation. In the boy's case the castration complex concludes the Oedipal phase whereas for the girl it precipitates it. The constraint of the erotic feelings and fantasies of the girl and her turning away from the mother to the father is an uneven and precarious process entailing “waves of repression”. The normal outcome is, according to Freud, the vagina becoming “the new leading zone” of sexual sensitivity, displacing the previously dominant clitoris, the phallic properties of which made it indistinguishable in the child's early sexual life from the penis. This leaves a legacy of penis envy and emotional ambivalence for the girl which was “intimately related to the essence of femininity” and leads to “the greater proneness of women to neurosis and especially hysteria.” In his last paper on the topic Freud likewise concludes that “the development of femininity remains exposed to disturbance by the residual phenomena of the early masculine period... Some portion of what we men call the ‘enigma of women’ may perhaps be derived from this expression