previous life-experience might be found in every dream. But we only need to assemble just so much material as is absolutely necessary in order to comprehend the dream’s meaning. The limitation of the material is obviously an arbitrary proceeding, according to that principle of Kant’s which defines to comprehend as “to perceive to the extent necessary for our purpose.” For instance, when undertaking a survey of the causæ of the French Revolution, we could in amassing our material include not only the history of medieval France but also that of Rome and Greece, which certainly would not be “necessary for our purpose,” for we can comprehend the historical genesis of the Revolution just as well from much more limited material.
Except for the aforesaid arbitrary limitation, the collecting of material lies outside the investigator’s discretion. The material gathered must now be sifted and examined, according to principles which are always applied to the examination of historical or any other experimental scientific material. The method is an essentially comparative one, which obviously cannot be applied automatically, but is largely dependent upon the skill and aim of the investigator.
When a pyschological fact has to be explained, it must be remembered that psychological data necessitate a twofold point of view, namely, the view point of causality and of finality. I use the word finality intentionally, in order to avoid confusion with the idea “teleology.” I use finality to denote the immanent psychological teleology. In so far as we apply the view point of causality to the material that has been associated with the dream, we reduce the manifest dream content to certain fundamental tendencies or ideas. These, as one would expect, are elementary and universal in character.
For instance, a young patient dreams as follows: I am standing in a strange garden, and pluck an apple from a tree. I look about cautiously, to make sure no one sees me.”
The associated dream material is a remembrance of having once, when a boy, plucked a couple of pears surreptitiously from another person’s garden.
