Dementia Praecox or the Group of Schizophrenias

"Our literature is replete with complaints about the chaotic state of the systematics of psychoses and every psychiatrist knows that it is impossible to come to any common understanding on the basis of the old diagnostic labels.... Thus, not even the masters of science can make themselves understood on the basis of the old concepts and with many patients the number of diagnoses made equals the number of institutions they have been too.... Errors are the greatest obstacles to the progress of science; to correct such errors is of more practical value than to achieve new knowledge. We have here eliminated chaos of terms behind which useful concepts of disease were mistakenly sought; we have eliminated a veritable forest of boundary posts, not one of which indicated any natural line of demarcation.... By the term „dementia praecox“ or „schizophrenia“ we designate a group of psychoses whose course is at times chronic, at times marked by intermittent attacks, and which can stop or retrograde at any stage, but does not permit a full restitutio ad integrum. The disease is characterized by a specific type of alteration of thinking, feeling, and relation to the external world which appears nowhere else in this particular fashion." Eugen Bleuler. Dementia Praecox or the Group of Schizophrenias. Translated by Joseph Zinkin. International Universities Press, New York, 1950.