Sigmund Freud is the first who thoroughly
analyses dreams, on scientific grounds. He starts from interpreting his own dreams and especially from the famous Irma's injection dream published in his monograph Dreams interpretation (1900).
In this book, which was frequently updated during his lifetime, we can
find not only the analysis of this dream but also other interesting topics related to dreams: a summary of dreams approach before Freud, a presentation of the way dreams are formed, symbol
analysis, a few interpreted dreams, ideas about the psychical mechanism structure etc.
After analyzing his dream by using the association method. Freud concludes dream have a meaning,
they represent a disguised accomplishment of unconscious desires. Many other interpretations confirm this opinion.
In addition, in Freud's opinion the dream function is to protect sleep.
There are several type of dreams – the desire (mostly sexual) or anguishes – which are as well subject to the desire accomplishment rule. Freud also publishes convenience dreams which are as
well subject to the rule he formulated.
Freud also interprets the so-called typical dreams
– flying or exam dreams – which are experienced by all people.
Further on, dream interpretation becomes an essential component of psychoanalysis as a an investigation method of the unconscious.