Conflicts and missed signals in psychoanalysis, behaviorism, and Gestalt psychology

At the turn of the 20th century, European psychologists found themselves in conflict situations with respect to the role that private mental states should play in a scientific psychology. Out of this conflict arose 3 of the best-known schools of the 20th century: psychoanalysis, behaviorism, and Gestalt psychology. Each of these schools is discussed with respect to two characteristics. First, the authors discuss the attitude of each school on the meaning of the word unconscious as it was understood around 1900. Second, the authors discuss the influence of each school on the reception accorded to books written around 1900 espousing viewpoints that did not cohere with the school's beliefs. Such books may be considered "missed signals" in the history of psychology. "Hits" associated with each school are also highlighted.