Sigmund Freud actually called dreams the "royal road to the unconscious," That statement will probably remain true in psychology forever. Freud's classic text, The Interpretation of Dreams, contains some of his finest work.

Freud believed every dream is a wish fulfillment, and he kept this theory to the end, even though he gave up his initial idea that all dreams have a sexual content.

For Freud, the concept of wish fulfillment didn't necessarily imply that a pleasure was sought, because a person could just as well have a wish to be punished. Nevertheless, this idea of a "secret" wish being masked by a dream remains central to classical Freudian psychoanalysis.

Freud said, "Dreams are not comparable to the spontaneous sounds made by a musical instrument struck rather by some external force than by the hand of a performer; they are not meaningless, not absurd, they do not imply that one portion of our stockpile of ideas sleeps while another begins to awaken. They are a completely valid psychological phenomenon, specifically the fulfillment of wishes; they can be classified in the continuity of comprehensible waking mental states; they are constructed through highly complicated intellectual activity".

It was not until Freud noticed how allowing his patients to freely associate ideas with whatever came to mind, that he really explored spontaneous abreaction. Freud himself suffered bouts of deep anxiety, and it was partly this that led him to explore the connection between association of ideas and dreams. In 1897 he wrote to his friend Wilhelm Fliess:

'No matter what I start with, I always find myself back again with the neuroses and the psychical apparatus. Inside me there is a seething ferment, and I am only waiting for the next surge forward. I have felt impelled to start writing about dreams, with which I feel on firm ground.'

This move toward dreams may have come about because in allowing his patients freedom to talk and explore the associations that arose - free association - Freud noticed that patients would often find a connection between the direction of their associations and a dream they had experienced. The more he allowed his patients to go in their own direction, the more frequently they mentioned their dreams. Also, talking about the dream often enabled the patient to discover a new and productive chain of associations and memories.

Freud began to take note of his own dreams and explore the associations they aroused. In doing so he was the first person to consciously and consistently explore a dream into its depths through uncovering and following obvious and hidden associations and emotions connected with the dream imagery and drama.

Obviously previous dream researchers had noticed how the dream image associated with personal concerns, but Freud broke through into seeing the connection with sexual feelings, with early childhood trauma, and with the subtleties of the human psyche. He did this to deal with his own neurosis, and he says of this period, 'I have been through some kind of neurotic experience, with odd states of mind not intelligible to consciousness, cloudy thoughts and veiled doubts, with barely here and there a ray of light.'

Using dreams for his self analysis, Freud discovered that previously unremembered details from his childhood were recaptured along with feelings and states of mind which he had never met before.

He wrote of this period, "Some sad secrets of life are being traced back to their first roots; the humble origins of much pride and precedence are being laid bare. I am now experiencing myself all the things that, as a third party, I have witnessed going on in my patients, days when I slink about depressed because I have understood nothing of the day's dreams, fantasies, or mood".

Without this powerful and personal experience of working with his dreams, meeting emotions and fantasies welling up from the unconscious, Freud would not have so passionately believed in his theories regarding dreams and the unconscious.

Of course, like much of Freud's theories, he related dreams to sex. One of his basic views of dreams was that the purpose of dreams is to allow us to satisfy in fantasies the instinctual urges that society judges unacceptable such as sexual practices. This was partly the reason for the enormous opposition and criticism that he met.

During the period of his early life, only men were believed to have powerful sexual urges. When Freud showed that repressed but obvious sexual desires were equally at work in women this created a social uproar. Perhaps his second finding in regard to sexuality surprised even him. During his analysis of women patients, sexual advance or assault by the woman's father was often revealed.

Freud struggled with this, wondering whether the assault was memory of an actual event, or a psychic reproduction of it. He eventually came to the conclusion that hysterical and neurotic behavior was often due to the trauma caused by an early sexual assault by the parent. Where there was not evidence of physical assault, then he saw the neurosis as due to sexual conflict or a trauma caused by some other event. This conflict was often manifested through dreams. This led to Freud being rejected by university colleagues, fellow doctors, and even by patients.

Another expert in the field of dreams and dream interpretation was Carl Jung.