I would like to treat briefly of some further problems of dream psychology, that border on the general discussion of dreams. Firstly, as to the _classification of dreams_; I do not wish to overestimate either the practical or theoretical significance of this question. I investigate yearly some 1500-2000 dreams, and this experience enables me to state that typical dreams actually do exist. But they are not very frequent, and from the view-point of finality they lose much of the importance which attaches to them as a result of the fixed significance of symbols according to the causal view-point. It seems to me that the _typical themes_ of dreams are of far greater importance, for they permit of a comparison with the themes of mythology. Many of these mythological themes--in the study of which Frobenius has rendered notable service--are also found in dreams, often with precisely the same significance. Unfortunately the limited time at my disposal, does not permit me to lay detailed materials before you: this has been done elsewhere.[193] But I desire to emphasise the fact that the comparison of the typical themes of dreams with those of mythology obviously suggests the idea (already put forward by Nietzsche) that from a phylogenetic point of view dream-thought should be conceived as an older form of thought. Instead of multiplying examples in explanation of my meaning, I will briefly refer you to our specimen dream. As you remember, that dream introduced the apple scene as a typical representation of erotic guilt. The gist of its purport is: "I am doing wrong in acting like this." But it is characteristic that a dream never expresses itself in a logically abstract way, but always in the language of parable or simile. This peculiarity is also a characteristic feature of primitive languages, whose flowery idioms always strike us. If you call to mind the writings of ancient literature--_e.g._ the language of simile in the Bible--you will find that what nowadays is expressed by means of abstract expressions, could then only be expressed by means of simile. Even such a philosopher as Plato did not disdain to express certain fundamental ideas by means of concrete simile. Just as the body bears traces of its phylogenetic development, so also does the human mind. There is therefore nothing surprising in the possibility of the allegories of our dreams being a survival of archaic modes of thought.