The prospective function, on the other hand, is an anticipation in the unconscious of future conscious achievements, something like a preliminary exercise or sketch, or a plan roughed out in advance. . . .
The occurrence of prospective dreams cannot be denied. It would be wrong to call them prophetic, because at bottom they are no more prophetic than a medical diagnosis or a weather forecast.
They are merely an anticipatory combination of probabilities which may coincide with the actual behaviour of things but need not necessarily agree in every detail. Only in the latter case can we speak of “prophecy.”
That the prospective function of dreams is sometimes greatly superior to the combinations we can consciously foresee is not surprising, since a dream results from the fusion of subliminal elements and is thus a combination of all the perceptions, thoughts, and feelings which consciousness has not registered because of their feeble accentuation.
In addition, dreams can rely on subliminal memory traces that are no longer able to influence consciousness effectively.
With regard to prognosis, therefore, dreams are often in a much more favourable position than consciousness.~Carl Jung, “General Aspects of Dream Psychology” (1916). In CW 8: The Structure and Dynamics of the Psyche. P. 493