Acute psychoses are characterized primarily by their manner of creation: We should consider as acute [Ed], using the word ‘acute’ [Ed] as it is used in other organic diseases, all of those mental disorders which develop within hours, days, or over several weeks to produce a significant level of symptoms. Further development of the illness is then subject to whether and for how long the patient remains in the acute stage, whether there is recovery, or whether the disorder progresses to a chronic condition. In the latter situation, acute psychosis merges into an acute initial stage of a chronic psychosis. With the same logic, acute stages of chronic psychoses presenting at times other than the initial period must be regarded as acute psychoses.

Gentlemen! Simple reflections will show you that, for symptoms derived from our schema, the symptomatology of acute mental illnesses is a field with no boundaries. Earlier we had come to realize that the activity of consciousness generates the content of consciousness, so that altered activity of consciousness must also result in changes in the content of consciousness; and we could thus define acute mental illnesses as the changes in content of consciousness taking place within a certain time frame (p. 54). However, now we can assume a priori [W] that such changes in content of consciousness during acute mental illnesses will be less fixed or shorter in duration than those in chronic illnesses. Nevertheless, the clinical significance of substantive disturbances of consciousness during acute mental illnesses is so significant and crucial for establishing the characteristics of illness that any teaching on illness which neglected this point of view in a one-sided manner would turn out to be insufficient to encompass the clinical facts. While in chronic psychoses or paranoid states we could limit ourselves mainly to changes in content [Ed] of consciousness, you should understand how much more complicated are our tasks in describing acute psychoses, where changes in activity of consciousness are just as important as the changes in its content.

In addition, secondary processes, which we saw added to various elementary symptoms in the chronic psychoses are, to a great extent, also present in acute psychoses. They may even be enhanced—for instance the principle of explanatory delusions; and, just as explanatory delusions do not in themselves represent abnormal activity, so in acute mental illnesses we will get to know new sources of delusion formation [W], which likewise are aspects of normal mental life. Experiences that we will gain in this respect, forming, in one sense, an addition to the theory of paranoid states, are also quite appropriately included here. A patient who is now due for discharge, and who has been free from psychotic symptoms for 3 months, offers us a good opportunity. He is a 27-year-old, academically-qualified mechanical engineer K. who is considered to have recovered from this, his second episode of a severe mental illness, complicated by his lack of insight into a few symptoms of his illness persisting from the time of its acute onset. He has a complete memory for the entire period, approximately 1½ years of illness, and his intelligence and training in scientific observation make him quite rare, as a reporter about certain symptoms.

I skip over the fact that this patient can give us a detailed account of the voices and autochthonous ideas at the time of his illness. We learn from this only that these familiar elementary symptoms of paranoid states often also occur in acute mental illnesses. Much more important for our purposes are the explanatory delusions which the patient connects to these experiences. He was, in fact, always fully aware that the voices, which he could see as having no objective basis, could not be explained by any physical means, and so there remained for him only the evidence of his senses, and—much as he struggled against it initially—the assumption of supernatural effects of ‘spirits’ [W]. He then attributed the strange thoughts as coming from these spirits; and the fact that they never led to a physical delusion of persecution but rather to the assumption of supernatural effects can, to some extent, be ascribed to this person’s scientific training. We see also from this example that delusions of explanation in acute mental illnesses [W] play no lesser role than they do in chronic states. Of course, as a prerequisite, there must be, to a certain degree, a retained ability to think—that is, there must be requirements of logic and the logical ability to provide explanations for these strange phenomena. In general, this condition corresponds, to some extent, to his discernment, as was mostly present in our patient. In addition, the content of explanatory delusions depends on individual characteristics of each patient. How much this is the case, you will see from a second case. Among thoughts that had been instilled in him, our patient announced that he had already been in the world several times, as Wotan, and as Ahlbrecht the bear. He therefore believed in transmigration of souls. When I asked him how he had imagined it, and if it was an act of resurrection, the patient expressed his view that the personality of every person should be viewed as a specific arrangement of material components, and he thought it possible that precisely the same order of molecules could be repeated at various times, and could produce the same person. Much as the patient himself now laughs at this assumption, you must admit that only a scientifically-minded person could formulate such an explanatory delusion.