In the translation of dream thoughts into dream content three principal mechanisms are at work: condensation, displacement, and moulding for presentability.
"The first thing which becomes clear to the investigator in the comparison of the dream content with the dream thoughts is that a tremendous work of condensation has taken place. The dream is reserved, paltry, and laconic when compared with the range and copiousness of the dream thoughts." "Every element of the dream content turns out to be over-determined - that is, it enjoys a manifold representation in the dream thoughts."
"In the formation of dreams those elements which are emphasized with intense interest may be treated as though they were inferior, and other elements are put in their place which certainly were inferior in the dream thoughts." "There has taken place in the formation of the dream a transference and displacement of the psychic intensities of the individual elements." "The process which we assume here is nothing less than the essential part of dream activity; it merits the designation of dream displacement. Dream displacement and dream condensation are the two craftsmen to whom we may chiefly attribute the moulding of the dream." "We are already acquainted with dream disfigurement; we have traced it back to the censorship which one psychic instance in the psychic life exercises upon the other. Dream displacement is one of the chief means for achieving this disfigurement." "We may assume that dream displacement is brought about by the influence of this censor, of the endopsychic repulsion."
."A third factor, whose part in the transformation of the dream thoughts into the dream content is not to be considered trivial, is the regard for presentability (German: Darstellbarkeit) in the peculiar psychic material which the dream makes use of - that is fitness for representation, for the most part by means of visual images. Among the various subordinate ideas associated with the essential dream thoughts, that one will be preferred which permits of a visual representation, and the dream activity does not hesitate promptly to recast the inflexible thought into another verbal form, even if it is the more unusual one, as long as this form makes dramatization possible, and thus puts an end to the psychological distress caused by cramped thinking."
"It has been my experience - and to this I have found no exception - that every dream treats of one's own person. Dreams are absolutely egotistic. In cases where not my ego, but only a strange person occurs in the dream content, I may safely assume that my ego is concealed behind that person by means of identification."
Freud's observations concerning the affects in dreams are of great interest: "The fact that in dreams the presentation content does not entail the affective influence which we should expect as necessary in waking thought has always caused astonishment." "I am in a horrible, dangerous, or disgusting situation in the dream, but I feel nothing of fear or aversion; on the other hand, I am sometimes terrified at harmless things and glad at childish ones. This enigma of the dream disappears more suddenly and more completely than perhaps any other of the dream problems, if we pass from the manifest to the latent content. We shall no longer be concerned to explain it, for it will no longer exist. Analysis teaches us that presentation contents have undergone displacements and substitutions, while affects have remained unchanged."