Otto Weininger illustrates the manifestations of unconscious phantasy in children – normal, neurotic or psychotic – in various settings such as playgroups, ordinary schools or special schools for disturbed children, the family milieu or play therapy. He uses Melanie Klein’s developmental theory and shows the evolutions of phantasies in their content, in the way they are symbolizes, and their functioning in terms of the child’s evolution from the paranoid-schizoid position to the depressive position and Oedipus complex.