By and large, definitions of “delusion” in the Diagnostic and Statistical Manual of Mental Disorders (DSM)—along with various other theoretical, explicative attempts thereof—adopt Karl Jaspers’ definition of schizophrenic delusions, which he defined as “false judgements ” in his General Psychopathology (Jaspers 1959/1997)¹. Thus, DSM-IV-TM defines schizophrenic delusions generally as “erroneous beliefs ” (1994, p. 275). Concurrent with his work on GP, however, Jaspers came into conflict with his own definition of schizophrenic delusion as false judgements, which he had adopted from his contemporaries. This accepted and general definition had its foundation in the so-called three criteria of delusion with explanations of the real “psychological nature” (“Wesen,” HH p. 80) of delusion. Going further, he differentiated between incomprehensible “primary delusional experiences ” (HH p. 82)^{2 , 3} and comprehensible delusional assumptions often originating from these. Following from this differentiation, he showed that primary delusional experiences are quite different than those delusional meanings arising from false judgements. For Jaspers, these are much more characteristic of a later stage of delusion. In the case of delusional perception, for example, the delusional meaning occurs as an “immediate intrusive knowledge of meanings” (own translation p. 83) and does not, as the DSM states, “involve misinterpretation of perceptions and experiences” (DSM p. 275). In other words, primary delusion has a different formal structure when compared to secondary stages of delusion. The definition of schizophrenic delusion as “erroneous beliefs” (DSM p. 275) and as consisting in “disease-induced misjudgement” (AGP system 58) relates almost exclusively to the delusion described by Jaspers as secondary. Due to a lack of appreciation about this distinction between judgement-based delusions and primary delusional experiences, the DSM neglects completely to discuss primary delusional experiences. Moreover, DSM adopts the three criteria of delusion posited by Jaspers but conceives of these with a total lack of phenomenological specificity. In other words, the definition is almost exclusively quantitative without Jaspers’ attempt to conceptualize this also in a qualitatively specified way.

Besides this explicative purpose of distinguishing Jaspers’ definition of primary delusional experience from the general, judgement-based definitions of the DSM, a secondary topic to be discussed is the possibility that the disturbance of the ego (or of the basic or bodily self), which one takes as characteristic of schizophrenic delusions⁴, takes place as a result of alterations of existential a prioris (i.e., basic categories of human existence). That would indicate a shift from being in the sense of Heidegger’s “Dasein” in the direction of a “reification” (“Verdinglichung”) of being. If this shift were indeed the case, then it would underline the importance of Jaspers’ phenomenological specificity regarding the criteria of delusion. Also, it would shed light on the specific formal structure of the schizophrenic primary delusion while partly reducing its incomprehensibility . To conclude this section concerning the secondary topic, some consequences for psychotherapy of delusion will be discussed.

Jaspers’ concept of delusional experiences of schizophrenics is highly significant for present psychiatry because he differentiates primary delusional experiences from the results of these, which occur when a patient tries to understand his (even for him) strange new experiences at the beginning of his delusion. In his own language, the primary delusional experience, that is, the “vivid givenness of the delusional contents,” occurs before changing into “solidified delusional judgements, only reproduced, discussed, dissimulated on any opportunity” (own translation p. 80); these later developments are often referred to as the so-called secondary delusion (s). This differentiation is important for two reasons:

The relevance of Jaspers’ concept of delusion is shown by the continual importance of his three criteria for the definition of schizophrenic delusion in the diagnostic manual of DSM-IV-TM. In the Table 8.1 we compare Jaspers’ definition of schizophrenic delusion to the definition in the DSM. However, if we take into consideration his own commentaries to his criteria, we recognize the far extent to which Jaspers’ concept of the real nature of schizophrenic delusion deviates from its definition in the DSM manual.

The general definition of schizophrenic delusions in the DSM as consisting in “erroneous beliefs ” that usually involve misinterpretations of perceptions or experiences seems confirmed by Jaspers, for he states that delusion is communicated by judgements (“pathologically falsified judgements,” HH p. 80). In the same chapter on “delusion and awareness of reality,” however, he comments and criticizes his own statement, and thereby also implicitly the definition in the DSM, when he posits: “To say simply that delusion is a mistaken idea which is firmly held by the patient and which cannot be corrected gives only a superficial and incorrect answer to the problem. The definition will not dispose of the matter” (HH p. 93). The psychological nature of delusion, according to Jaspers, is not sufficiently explained by the mere external characteristics of the pathologically falsified judgements. We have to take into consideration also the original experiences on which the judgements are based as a “secondary product.” This becomes particularly clear, when he speaks about the primary experiences of delusional perception: “We have here not to do with interpretations of the character of judgements….⁵ The meaning is experienced immediately…” (own translation p. 83). Thus, primary delusional experiences do not “involve a misinterpretation of perception or experiences” (275) as formulated in DSM-IV-TM. Misinterpretations are characteristic for a secondary stage of delusion. In its formal structure, primary delusional experience is different from secondary stages of delusion, at which delusion may involve erroneous judgements. Evidently, the general definition of delusion of the DSM neglects the primary delusional experience completely, if accept Jaspers’ point that erroneous judgements are different from delusions when considered according to their nature (“Wesen”). For Jaspers, proper delusions are “elementary,” “immediate and final experiences” (own translation p. 110), as opposed to erroneous judgements arising only secondarily via thinking: “The elementary experiences psychologically cannot be influenced opposite to that which is mediated by thoughts. They are primarily without content” (own translation p. 110). Erroneous delusional interpretations of the secondary delusional stage are often called “extra explanatory delusion.”⁶ This secondary stage remains, however, intrinsically connected with a delusion proper insofar as its content relates to primary delusional experiences. The erroneous interpretations present the patient with a means to adapt his primary delusional experiences to common reality. This understanding of schizophrenic secondary stages of delusion maintains validity (as we will show below) regarding the inability to correct these delusions, which in its specificity also relates to the primary delusional experience. If we adhere to Jaspers’ general definition, then the definition of delusions as “erroneous beliefs” in the DSM and its foundation can be questioned.

The question whether delusion is merely an erroneous belief characterized by erroneous interpretations is not only important for conceptual and diagnostic reasons but also for psychotherapy. If convinced that his delusional assumptions are solely erroneous beliefs , then the patient finds himself in self-contradiction due to his attempts to “normalize” his primary delusional experiences . By trying to adapt his primary delusions to be normal, the situation can even worsen; for the self-created erroneous reality may return him back to his primary delusional experiences, which, in turn, become more dreadful because they seem impossible to alter. Without this differentiation, we, as psychiatrists, would fail to recognize that the primary delusional experience is the main “generator” of delusion, rather than the errors revealed in one’s judgements.

Now let us return to our table. Jaspers’ three characteristics of false judgement are summarized under criterion A1 in the DSM-IV-TM. Criterion A1 is given if delusions are bizarre. Further, hallucinations are considered bizarre if these involve “commenting” or “conversing” voices. This single criterion of bizarreness is judged as being so important for the diagnosis of schizophrenia that “only this symptom is needed to satisfy criterion A1 for schizophrenia” (p. 275). “Bizarre” is defined as being “clearly impossible and not understandable, not deriving from ordinary life experiences” (p. 275). It comprises delusions that express a loss of control over mind or body, or the patient’s beliefs that “his or her thoughts have been taken away by some outside force (‘thought withdrawal’), that alien thoughts have been put into his or her mind (‘thought insertion’), or that his or her body or actions are being acted on or manipulated by some outside force (‘delusions of control’)” (p. 275). We will return to this topic of bizarreness below.

Let us cover what Jaspers says about “primary delusional experiences ” (own translation p. 82) (“primäre Wahnerlebnisse”). “Primary” here is used in the sense that the delusion occurs before its development into false judgements . In the description of these experiences, Jaspers places the emphasis on formal aspects, that is, on the “how” of experiences and not so much on the “what” (or the content) of those experiences—the latter of which takes up the foreground of the diagnostic manuals today. The “how” of experiences, in the wider sense of our understanding, relates not only to symptoms (e.g., first rank symptoms and Jaspers’ criteria of delusion), but also to the relationship of the patient to himself, to the world and to others.