The ancient Greeks were concerned with psychology in their search to define the ideal society and the ideal citizen. The phenomenon of hypnosis pointed the way to the scientific discovery of the unconscious and marks the beginning of the great psychodynamic therapies which concieve mind as a dynamic interplay between conscious and unconscious mental processes. Hypnosis was discovered by a French nobleman Puysequr who investigated the experiments of F.A. Mesmer. By the mid-19th century investigations in hypnotism had established a number of genuine hpnotic effects including amnesia, suggestion, paralysis and anaesthesia. These were later discovered to have a marked similarity to the condition of mental patients suffering from paralysis and hysteria, and this connection was later investigated by the French neurologist Jean Charcot and by Sigmund Freud, the architect of psychoanalysis and the father of all modern psychodynamic, psychological movements.
Psychoanalysis is Freudian psychology.
Freud developed its key concepts in the course of fifty years' work. These concepts are the defence mechanisms , free association , interpretation resistance , transference and unconscious. He discovered that dreams are the 'royal road' to the unconscious and was the first person to understand the nature of infantile sexuality found in the reminiscences of his adult patients. Freud's model of mind is a scientific, mechanistic one which therefore has elements of determinism . He broke with Freud because of Freud's adherence to the exclusively sexual nature of the libido , or psychic energy.