Symbols
Symbols are an important part of how dreams work, says Freud, because a dream participant will encounter an object in their dream that signals emotional memories or ideas that are not perfectly contained in the object alone. For instance, a person might dream about carousels (this is one of his examples), but a carousel might mean different things to different people depending on the concepts and memories one believes about carousels. Therefore, a dream might have symbolism in it that is open to interpretation.
Childhood, a motif
A common variety of dream is the motif of childhood, as in "I dreamt I was taking a test and failing," or "I dreamt I was on stage, and I was embarrassed in front of the whole school." The strangeness of these dreams is that a person's self still has those childish emotions available to them in dreams, so that in dreams, a person can be resubmitted to the state of innocence and dependence that shapes the childhood experience, for purposes that are strange and worth exploring, says Freud.
Archetypal dynamic
This book suggests that perhaps a dream can take on archetypal shapes in the design of the dream (especially emotionally) so that a person can explore various essential roles. For instance, a person might encounter some kind of divine visitor or helper, or perhaps a dream goes the other way and they find themselves subjected to sublime encounters that leave them horrified, like nightmares. This is important, because archetypal themes are explored in literature, so that books and myths can be used as interpretive tools when helping a client understand some recurring dream that might be bothering them.
Death through motif
Freud's theory includes death fear, because he feels that some dreams seem designed to help a person confront death. Many times, they encounter dead members of their own family, or perhaps they encounter an important symbol for death. Freud mentions passages as symbols for death (like a train or a car), and he mentions physical ailment in relationship to the death of the body, like losing one's teeth (a symbol for the ominous effects of time and decay).
Interpretation as a practice
Freud's book is a platform for several different discussions or styles of dream-interpretation, and he suggests to his reader (the dream interpreter, i.e., a psychotherapist), that perhaps a person must practice interpretation to become good at it. In other words, he says that the imagination is a kind of problem-solving machine, and he warns against malpractice by suggesting the diversity of dream theory. He himself argues for various competing theories about what dreams are and what they "mean," so that people will take a tentative, scientific stance about dreams, given their mysterious nature.
