The author analyses several interpretations published by different authors from the point of view of their linguistic form and the type of language used, in order to determine the therapeutic effect and the manner of working of each.

Two types can be distinguished: literal-explanatory language and metaphorical language. Each performs a different function. Metaphorical language is proper to the primary process; it is related to displacement and condensation; it reactivates the most primitive levels of the mind; it serves the purpose of expressing affects and emotions. Literal-explanatory language is proper to the secondary process; it is related to logicalformal thought; it reactivates the most highly developed levels of the mind; it serves a referential, informative and explanatory purpose.