Gentlemen!

Our subject here, learning about mental illnesses, is essentially a branch of internal medicine which, because of its practical significance and for other reasons of a more external nature, has required—and has received—special treatment from time immemorial. Sadly, at the same time, it is an area that is backward in its development: It presently stands at the point where the rest of medicine was, about a 100 years ago. You will be aware that at that time an evolved pathology in the modern sense, that is, one supported by pathological disturbances in individual organs of known function, still did not exist, and that, accordingly, people ascribed the status of disease classes to certain frequently-occurring symptoms, albeit in widely varied groupings. Given such an attitude, medical knowledge of diseases did not go far beyond knowledge currently found among the lay public, when it treats coughing, palpitations, fever, jaundice, anaemia, and emaciation as actual illnesses. This is precisely the current attitude towards psychiatry, at least amongst the majority of ‘mad doctors’—its proponents. Even for them, some specific symptoms form the very essence of the disease—for example a depressed mood, in the broadest sense, is the essence of melancholy; an elevated mood with excessive movements, that of mania, and so on. People now distinguish many such types of putative disease. However, since in Nature combinations of symptoms are far more diverse and complex, it has been necessary to construct an artificial framework, sometimes more widely, and sometimes more narrowly, accomplished by different observers in very different ways. Despite all efforts to bring the cases of illness artificially into one form fitting within the framework, very many cases remain that cannot be correctly assigned, and in no way fit the framework. Indeed, anyone who can judge without bias, and has the necessary experience, will find that the great majority of cases do not conform to the normal viewpoint. I readily concede that psychiatry has demonstrated substantial progress in more recent times. Work of men like Griesinger, H. Neumann, Kahlbaum, Meynert, Emminghaus, and many others has not been in vain. Yet even these outstanding researchers all still gave in to the temptation of confusing individual symptoms with the essence of the illness; and the low level of average grasp of psychiatry even today can be assessed by the prevailing doctrine of lunacy, the merits of which are realized by a convenient nomenclature. Psychiatry today enjoys more general recognition, and this would have been welcomed as progress by a thinker like Meynert [1] in his time.

Under these circumstances, the teacher of psychiatry is strongly advised that if he wants to apply standards of another discipline, he should stay just with symptoms. However his task is clearly predetermined for him: He should proceed as in the sister disciplines of medicine: Symptoms must be deduced from familiar features of the diseased organ, in order to treat the illness—in our case from features of the brain. Only in this way do we have the prospect of obtaining a classification and overview of symptoms which is both natural (i.e. based on the nature of things) and, at the same time, exhaustive.

The assumption that mental illnesses are brain diseases is probably not contested by any specialist today. If we start from there, we must soon expand, by indicating brain diseases of a particular type, and at a particular site, for they are in no way identical with so-called organic brain diseases with which we are far more familiar. Let us recall the division of brain diseases into focal disease processes and general diseases; mental illnesses will certainly not be subsumed under the former, but possibly under the latter. As is commonly known, two general diseases can be classed amongst organic brain diseases: meningitis and progressive paralysis. Nothing would stop us from proposing mental illnesses as a third category of general disease. However, the question then arises: What are the fundamental characteristics that distinguish this third category of general diseases of the brain from the other two so-called organic diseases?

To approach this question more closely, we must focus for a moment on symptoms of brain diseases. All symptoms of brain diseases are, as we know, either focal or general. The two general diseases of the brain just mentioned amongst organic brain diseases are examples of diseases with mainly general symptoms in their clinical picture. However, they are really characterized by the fact that focal symptoms occur along with general ones. Indeed, one can probably say that these focal symptoms are never totally absent. Mental illnesses in contrast present no such focal symptoms. Accordingly, mental illnesses would represent general diseases of the brain of a particular type that are never accompanied by focal symptoms.