The principles according to which psychoanalysis solves dreams are therefore exceedingly simple, and have really been known for a long time. The further procedure follows the same path logically and consistently. If one spends considerable time over a dream, which really never happens outside psychoanalysis, one can succeed in finding more and more recollections for the separate dream parts. It is, however, not always possible to discover recollections for certain other parts; and then one must leave them for the time being, whether one likes it or not. When I speak of "recollections" I naturally do not mean merely memories of certain concrete experiences, but also of their inter-related meanings. The collected recollections are known as the dream material. With this material one proceeds according to a scientific method that is universally valid. If one has any experimental material to work up, one compares its separate parts and arranges them according to their similarities. Exactly the same course is pursued in dealing with the dream material; one gathers together its common characteristics, whether these be formal or material. In doing this one must absolutely get rid of certain prejudices. I have always observed that the beginner expects to find some tendency or other according to which he endeavours to mould his material. I have noticed this particularly in the cases of colleagues who were previously more or less violent opponents of psychoanalysis, owing to their well-known prejudices and misunderstandings. When fate willed that I should analyse them, and they consequently gained at last an insight into the method of analysis, it was demonstrated that the first mistake which they had been apt to make in their own psychoanalytic practice was that they forced the material into accord with their own preconceived opinions; that is, they allowed their former attitude towards psychoanalysis, which they were not able to appreciate objectively, but only according to subjective phantasies, to have its influence upon their material. If one goes so far as to venture upon the task of examining the dream material, one must permit no comparison to frighten one away. The material consists, as a general rule, of very unequal images, from which it is under some circumstances most difficult to obtain the "tertium comparationis." I must forego giving you detailed examples of this, since it is quite impossible to introduce such extensive material into a lecture.