The Interpretation of Dreams by Sigmund Freud Chapter 7 Page 16

two exits for the individual unconscious emotional process. It is either left to itself, in which case it ultimately breaks through somewhere and secures for once a discharge for its excitation into motility; or it succumbs to the influence of the foreconscious, and its excitation becomes confined through this influence instead of being discharged.

It is the latter process that occurs in the dream. Owing to the fact that it is directed by the conscious excitement, the energy from the Forec., which confronts the dream when grown to perception, restricts the unconscious excitement of the dream and renders it harmless as a disturbing factor. When the dreamer wakes up for a moment, he has actually chased away the fly that has threatened to disturb his sleep. We can now understand that it is really more expedient and