Authorities agree that in schizophrenic thinking disorders there exists a lack of differentiation between the concept of the concrete object and the symbol. This paper specifically deals with the lack of discrimination between the concrete and the metaphoric, leading to a failure to think in a realistic way.

Two cases are discussed as examples of such thinking. With therapy, improvement occurred when thinking lost its undifferentiated quality. The cases illustrate the author's thesis that in order for this differentiation to occur the patient must develop firm ego boundaries. This happens as the need for defense manifested by the regressed state lessens concomitantly with the ego's ability to tolerate repressed impulses. Need for intimacy and empathy in the treatment is stressed.