The case of little Hans, or Analysis of a Phobia in a Five Year Old Boy, is one of Freud's classic case studies. Any student of Freud or psychoanalysis must read this one, if only because you need to know. Little Hans has a classic Oedipal complex, hate of the father, love of the mother and rampant infantile sexuality. Through this study Freud reveals processes of traumatic substitution, condensation, anxiety and the development of screen memories. Rat Man provides a more obvious incidence of childhood sexual perversion, in this case due to sexual abuse, and the development of a child's moral dilemma into obsessive neurosis. The Rat Man's neurosis is characterised by, at one time, an erotic wish, or desire, and revulsion at this erotic wish. Again there is infantile sexuality and the desire to kill the father.