Sigmund Freud,
A General Introduction to Psychoanalysis
“ THE DREAM Manifest Dream Content and Latent Dream ThoughtWE have not studied the problem of errors in vain. Thanks to our efforts in this field, under the conditions known to you, we have evolved two different things, a conception of the elements of the dream and a technique for dream interpretation. The conception of the dream element goes to show something unreal, a substitute for something else, unknown to the dreamer, similar to the tendency of errors, a substitute for something the dreamer knows but cannot approach. ”
