Sigmund Freud is the father of psychoanalysis accredited as being one of the most influential and authoritative thinkers of the twentieth century. Freud's often-controversial theories appealed to the world as bold new attempts to explain the unexplainable. He lived by a theory that reason can explain everyday behavior. Freud believed that there existed two mental states the conscious and the unconscious. He emphasized the unconscious as being a constant influence on the human behavior. As an example a man bumping into a women may be thought of to him and her as accidental, but in actuality it was the man's unconscious attraction and desire for her that made him bump into her.

The accident fulfills a sense of pleasure for the unconscious thought because the man has now entered the woman's personal space. Freud also incorporated a third consciousness the pre-consciousness, the place where memories and day to day things are stored. These levels are what he believed the human mind consisted of. Freud worked the early part of his career with a Viennese colleague and friend Josef Breuer who influenced much of his work later on. Working with Breuer, Freud came up with the idea that phobias, pains, paranoia's and etc. had their roots in a previous experience hidden in the unconscious.

Breuer experimented with hypnosis techniques and found that recalling memories of the unconscious relieved symptoms of patient's ills. These conclusions influenced Freud to think that the workings of the mind could not be strictly physical causes. Freud felt that unconscious thought could be suppressed but not hidden altogether revealing them selves in dreams, slips of the pen and tongue. This unconscious thought or mental state cannot be brought to the forefront of consciousness ultimately determining the actions of the conscious self. He believed that the unconscious mind could be repressed but not hidden altogether. All this emotional energy within the human personality was given the name of the 'id' by Freud.

According to Freud the id is concerned with satisfying all basic urges from thirst and hunger to sexual desire and determined to achieve satisfaction at any cost. The desires of the id are often placed in the subconscious usually manifesting themselves in the form of wishful fulfillment of dreams, so that the individual is not damaged by the suppression of these thoughts. Freud believed that sexual energy (libido) is the singles most important motivating force in the adult life. The id's power was derived from the primitive human hedonistic instincts. Society could not function at all if these instincts were not hidden and could be released all the time. There would not be anyone to hold the law and society would be out right dysfunctional.

Therefore Freud concluded that another element of the mind, the 'ego', directs these instinct into channels that are socially acceptable. These channels are defined by the 'superego' which enforces cultural morals, parental and social standards of behavior. Freud thus looked upon the human mind as a battlefield in which the id was constantly trying to prevail while the superego is trying to restrain it. Sometimes the superego is a winner and sometimes it is not. Unconscious energy is then surfaced and becomes neurotic behavior or even a disabling mental illness. Freud's treatment for instincts and the outburst of physical energy is psychoanalysis.

He concluded that the constant tension between instincts and repression constantly shapes societies and most of all, individual personalities. Social organization put a huge burden of guilt on humans for the repressed instincts. People's instinct to love is basically counterbalanced by their impulse to destroy one another, because guilt has found its outlet in violence. Freud believed that humans were naturally aggressive and seeking to destroy each other. Freud had yet another theory that intertwined with the theory of unconsciousness this was the theory of infantile sexuality. He believed that his theory on infantile sexuality was the root of the unconscious and many neurotic illnesses.

This theory is more or less a theory on human personality. According to this theory upon a child's birth it is driven by a desire or drives of bodily / sexual pleasure or a Freud would say the release of mental energy. Infants initially gain this release and get pleasure through the act of sucking in which Freud terms this the 'oral's tage of development. This is followed by the 'anal's tage of development in which the focal point of pleasure or energy release is found in the anus, particularly in the act of defecation. Soon the young child develops a deep sexual attraction for the parent of the opposite sex, and hatred of the parent of the same sex, the infamous Oedipus complex. The child then realizes that he could never replace the stronger parent and a feeling of guilt sets in.

The conflict is resolved then by coming to identify with the parent of the same sex. This happens at the age of five when the child enters a 'latency' period in which sexual motivations become less defined. This last until puberty, when mature genital development begins and the pleasure drive refocuses around the genital area. This, Freud believed, is the sequence or progression implicit in normal human development and it is to be noted that the infant level and the instinctual attempts to satisfy the pleasure drive are frequently checked by parental control and social influence. The development process is crucial to adult mental health. Many mental illnesses particularly hysteria can be traced back to unresolved conflicts experienced at this stage.

Freud's many theories changed the thinking of the world and especially the newly emerging field of psychology during the twentieth century. His theories of the unconscious and infantile sexuality were bold and controversial. Influenced by many scientists his work was genuine and unique in the 20 th century world of scientific thought. Many of his theories would be altered and or rejected by many thinkers but they live on still today..