I must assume that the sensory surface of consciousness devoted to the
Forec. is rendered less excitable by sleep than that directed to the
P-systems. The giving up of interest for the nocturnal mental processes
is indeed purposeful. Nothing is to disturb the mind; the Forec. wants
to sleep. But once the dream becomes a perception, it is then capable of
exciting consciousness through the qualities thus gained. The sensory
stimulus accomplishes what it was really destined for, namely, it
directs a part of the energy at the disposal of the Forec. in the form
of attention upon the stimulant. We must, therefore, admit that the
dream invariably awakens us, that is, it puts into activity a part of
the dormant force of the Forec. This force imparts to the dream that
influence which we have designated as secondary elaboration for the sake
of connection and comprehensibility. This means that the dream is
treated by it like any other content of perception; it is subjected to
the same ideas of expectation, as far at least as the material admits.
As far as the direction is concerned in this third part of the dream, it
may be said that here again the movement is progressive.

To avoid misunderstanding, it will not be amiss to say a few words about
the temporal peculiarities of these dream processes. In a very
interesting discussion, apparently suggested by Maury's puzzling
guillotine dream, Goblet tries to demonstrate that the dream requires no
other time than the transition period between sleeping and awakening.
The awakening requires time, as the dream takes place during that
period. One is inclined to believe that the final picture of the dream
is so strong that it forces the dreamer to awaken; but, as a matter of
fact, this picture is strong only because the dreamer is already very
near awakening when it appears. "Un rêve c'est un réveil qui commence."