This experimental dream confirms therefore the general principle formulated by Freud from the analysis of dreams in which the causal factor is an inferred wish. It is likewise on the assumption of my having correctly inferred this factor that I have insisted that a dream may be a fabricated expression of thoughts other than wishes or may be the solution of an unsolved problem. In this last case _the dream phenomena and mechanism seem to be analogous in every way to the subconscious solution of mathematical problems_ which I have already described. In such and other cases the subconscious process would seem to be a continuation and elaboration of the antecedent suggested problem. In dreams, then, or, as we should strictly limit ourselves for the present to saying, _in certain dreams_, there are, as Freud first showed, two processes; one is the conscious dream, the other is a subconscious process which is the actuated residuum of a previous experience and determines the dream.[104] It would be going beyond the scope of our subject to enter into a full exposition of this interpretation at this time and I must refer you for a discussion of the dream problem to works devoted to the subject. We have not, of course, touched the further problem of the _How_: how a subconscious intelligence induces a conscious dream which is not an emergence of the elements of that intelligence into self-consciousness, but a symbolization of them. This is a problem which still awaits solution. From certain data at hand it seems likely that so far as concerns the hallucinatory perceptual elements of a dream they can be accounted for as the _emergence of the secondary images_ pertaining to the subconscious “ideas.” The following observation is an _example of subconscious versification and_ also of _constructive imagination_. It also, I think, gives an insight into the character and content of the underlying process which constructs a dream. I give the observation in the subject’s own words: "I woke suddenly some time between three and four in the morning. I was perfectly wide awake and conscious of my surroundings but for a short time—perhaps two or three minutes—I could not move, and I saw this vision which I recognized as such.