In 1899 Freud published for the first time the work that would be considered the most important, representative and influential of his entire production: The interpretation of dreams. With it he began a new discipline, psychoanalysis, which proposed the way through which to access the unconscious taking elements of the lived experiences. For the first time the concept of the "I" was introduced and the dreams were the object of a scientific study. Thanks to the method proposed by Freud, they could be interpreted the contents of those, generally as the representation of latent desires. The interpretation of dreams is a fundamental book for those who want to know or deepen the theories of the father of psychoanalysis.