In this program attention is first directed to the general conceptions of what in medicine shall be called "disease" and some criteria are outlined by which "nosology" may be considered as a series of useful fictional conceptions. Inasmuch as some logicians have emphasized that a complete definition must contain everything that is known about a subject, and of what subject in medicine can one flatter oneself to have complete knowledge, so the catchword definitions usually employed must be recognized as etymological fictions and not as complete summaries of the behavior of things. Thus instead of saying "What is Epidemic encephalitis? or "what is schizophrenia?" this program would substitute the wording, "by what series of behavioristic anomalies induced by certain series of factors, upon variable backgrounds, shall be agreed upon to designate one series of groupings as encephalitis and another as schizophrenia?"Having marked out the territory thus agreed upon, "epidemic encephalitis" is given a certain autonomy with a fairly comprehensive recognition of somatic, neurological and psychiatric phenomena, induced by exogenous factors as yet not known with very distinct histopathological findings involving the whole body. For the purposes of this discussion attention is directed to the lesions of the mid-brain, interbrain, thalamic and cortical reflex arc pathways, acting upon constitutional backgrounds as yet not capable of formulation. Almost complete skepticism is expressed as to the value, as yet, of rabbit animal experimentation and Jahnel's study of 1925 is coincided with in that at least 20 different known substances from spittle to the hay bacillus will cause some type of encephalitis in rabbits indistinguishable from each other.Greater difficulty in outlining a conception of schizophrenia is indicated but apart from the phenomenology, the histopathology and its localizations, also distributed throughout the entire body, an emphasis is laid upon the function of symbols as being as capable of producing changes in bodily structure as toxins or other mechanically considered noxæ.A slight outline of the experimental proof of empirically held beliefs in psychiatry, as the type of work of Pavlow, Cannon and others has demonstrated, is a contribution to this discussion.The general dynamic concept of the energy hypothesis is dealt with and the body as a whole reacting to environmental stimuli, inside or outside, in accord with the principle of evolution and dissolution of functions as indicated by Spencer, by Jackson, and by v. Monakow is outlined.From this discussion there emerges, by way of a rough metaphor, the image of an overlapping of two or more circles, in which certain behavioristic similarities occur in the two so-called "diseases."The acute phases of encephalitis are purposely passed by so far as their psychotic picture is concerned. Here one often finds acute confusional states which, as such, may be paralleled by similar pictures from a great variety of etiological factors, infections, toxic, endogenous, etc.It is more particularly the purpose of this discussion to deal with the more prolonged or residual, or progressive chronic phases in which the similarities appear and render a diagnosis, in the narrow sense, obscure. Furthermore the discussion, in attempting to bring out similarities and variations in the syndrome would hope to arrive at a more monistic point of view than a narrow mechanistic effort to explain psychopathological data by somatic pathological conceptions. In no field of neuropsychiatry has a greater analytic opportunity been offered to explain the physiopathology of psychomotor manifestations than that which this overlapping or partial identification of behavioristic anomalies in encephalitis and schizophrenia shows itself, especially the hebephreno-catatonic mosaic. It is further advocated that when encephalitis is studied from the more recent aspects of psychiatric research as valuable a series of correlations for psychopathology will be forthcoming as have emerged for physiopathology.As to some of the more specific comparisons the field of syndromy is first considered. Here encephalitic and catatonic psychomotor resemblances are obvious and fascinating chiefly because of the widening of present-day conceptions about the phenomena themselves. These akinetic and hyperkinetic motility disturbances are seen to be more complex than heretofore envisaged and in the encephalitis frame, the more complex schizophrenic panel is partly dissected.Whether one enters the territory through the older psychiatric gateway, first clearly constructed by Wernicke, or by the newer avenues opened up through the encephalitis syndrome following the lead of Naville's discussion of bradyphrenie it makes but little difference, since a very great rapprochement is evident and anatomical analysis of functional chaining is furthered.So far as specific syndromy comparisons are available attention is first called to the antithesis of a number of observers who claim identity of syndromy, notably some of the French school—only to speak of a few—Logre, Briand, Laignel Lavastine and others, and the contrasting views of Schilder, Dimitz, Gerstmann, Steiner, and many others.A simple list of the similarities would not be of interest, nor can all the phenomena be given in résumé. Some in the akinetic group, where a lack of spontaneity is associated with rigidity may be selected. Here the catatonic picture is very closely imitated, but a host of observers have pointed out the phasic mutations of this syndrome and have shown how readily in the encephalitic the whole thing is resolved by outside influences—daylight, command, music, laughter, optical stimulus, etc., and then the rigidity reasserts itself. Such coupling and uncoupling offers new analytical problems from both somatic and psychopathological fields. Echolalia, echopraxia, echographia, micrographia are discussed from this point of view.The numerous single or small group muscle hyperkinesias, the Schnautzkramp, facial distortions, bizarre movements, occupational perseverations, finger eccentricities, rubbing the nose, boring the ears, etc., these are discussed from the older tic points of view and the newer psychopathological points of view. Thus one arrives at a far greater insight into the structural correlates of parts of the complex schizophrenic symbolisms. A popular song which says, "Every little movement has a meaning all its own," may be put into the James-Lange formula by saying, "Every little movement has a feeling all its own," and study of the encephalitic movements enable one to resolve some of the components of the much more complex "feeling" envisaged as Hughlings Jackson has done.Cataleptic rigidity is of much interest for here one sees a number of dismemberments of a compound. One interesting characteristic of the encephalitic rigidity is brought out by forced movement. The flexibilitas cerea of the catatonic is quite a different response. When one turns to introspection one finds that the explanation of these akinetic and hyperkinetic activities is quite different in the two categories. These are gone into in detail. One aspect emerges quite distinctly. The explanation in the encephalitic tends more to rationalization—that of the schizophrenic towards a distorted symbolism. When Montaigne said, "He liked peasants because they were not educated enough to reason illogically"—here it is contended that the illogical rationalization of the encephalitic stands in contrast to the very logical—usually called crazy—but reality statements of the schizophrenic. If one knows the primitive language of symbolism, the regression of the schizophrenic to the peasant level makes him tell the truth, but interestingly camouflaged.This paper has a section devoted to the conception of the "Mangel an Antrieb" in encephalitics as contrasted with the schizophrenic phenomena of negativism. Here again the encephalitic simpler process offers a partial dissection of the complex telencephalic dynamics of negativism. These psychical correlates of akinesis are not correlates as Hauptmann terms them, they are partial constituents. The encephalitic dynamics are always simpler; i. e., utilizing lower reflex arc pathways than the schizophrenic.In some such simple way it is pointed out that a bulbocapneine rigidity like an encephaltic one may be an equivalent of a subthalamic Sherrington section, whereas a schizophrenic rigidity involves upper extensions in the functional psychomotor arcs.A host of other psychomotor equivalents must be passed by and the histopathological picture is next discussed. Here contrasts as to type of involvement are striking but serious difficulty is present, namely, that acute encephalitic cases are apt to be fatal, whereas the schizophrenic histological material is chiefly derived from old material, or if from recent cases, dying of pneumonia, appendicitis, suicide. The type of similarities which are under revision have not been so much in evidence—or been heretofore taken into consideration. But so far as one now can see the lesions are quite dissimilar. The studies of Saito, Mott, Lewis, Josephy, Buscaino, Alzheimer and others, for schizophrenia are briefly indicated, while the numerous studies on the histopathology of encephalitis are rapidly summarized. Schizophrenic changes may be envisaged more as parenchymatous degenerations and have a widespread non-neurological pathology as well. Encephalitis shows vascular infiltrating extravasation types of pictures. The localizations have a tendency to be cortical and striatal respectively although this would need several hundred pages to more correctly delimit, for the thalamic, striatal and mid-brain pathology of schizophrenia is also quite manifest. Apart from a large number of intricate problems all discussed the short differentia may remain as here stated.Finally a word as to the desirability of a more monistic conception of the phenomena in question. If one really deals with a psychobiological conception of the human body the fine-spun polemics as to differences between soma and psyche, or body and mind, have relatively little significance. One does not change a human being's action patterns in their wish capacity by any type of pathological process. Such a process only makes it incumbent on the effectors to try to arrive at the purposeful goals by other pathways, hence the changes in the phenomenology. Structural correlates for all activities are obvious—but what is not so plain is the functional complexities hidden behind relatively simpler structures. Mind is behavior, but of a highly complex blending of the body as a whole. In this sense as White has recently pointed out psyche and soma are born at the same time. Every disease, speaking generally, has a psychic component. This is good Hippocratic doctrine.A great contribution will come to an understanding of some of the complexities of human behavior through analysis of the less complete dissolution of mental function in encephalitis. In the psychoanalytic discipline it is the so-called educated man who is the most difficult to dissect into his component parts. Bits of dissected-dissociated mental machinery are scattered all over the place in schizophrenia, for one who can read them. The encephalitis material offers an excellent half-way series of disorganizations which will offer much for analytic research.