The present paper investigates the methodology involved in Jaspers’ psychopathology and compares it with Husserl’s phenomenology and with Dilthey’s cultural science. Allgemeine Psychopathologie and other methodological works by Jaspers, the works of Husserl and Dilthey that Jaspers cited, and previous research papers on Jaspers are reviewed. Jaspers had conflicting views on understanding, which were comprised of both empathic understanding and rational, ideal-typical understanding. Such a standpoint on understanding is considerably different from Dilthey’s. Additionally, the present paper reconfirms that Jaspers’ ‘phenomenology’ as a form of descriptive psychology for the understanding of empirical psychic states is different from Husserl’s phenomenology. Thus, this paper casts doubt on the common opinion that Jaspers was under the profound influence of Husserl or Dilthey.

The present study explores and compares Jaspers' methodology of psychopathology with Weber's methodology of sociology. In his works, Weber incorporated the arguments of many other researchers into his own methodology. Jaspers respected Weber as a mentor and presented arguments that were very similar to Weber's. Both Weber and Jaspers began from empathic understanding, but at the same time aimed for a rational and ideal-typical conceptualization. In addition, their methodologies were similar with respect to their detailed terminology. Such similarities cannot be seen with any other scholars. This suggests that Weber may have played an integral role as a mediator between his contemporary scholars and Jaspers. Thus, Weber may have had the most significant influence on Jaspers.

The present article revisits the theoretical model of schizophrenia by Hiroshi YASUNAGA . Yasunaga restated ego disturbance in schizophrenia as the "Pattern Reversal" between selfhood and otherness, based on British philosopher Wauchope's concept of "pattern." This concept is meant as asymmetrical relatedness (A/B) within a pair of concepts, such as life and death, quality and quantity, and self and other, prioritizing the former (A side) over the latter (B side). When applied to the pair of self and other, the pattern is vital for human experiences, and its disruption fundamentally alters every lived experience. Subsequently, Yasunaga extended the theory of pattern and invented his original "Phantom Space Theory," in which he postulated "Phantom Space," an experiential space that constitutes system a (A-side-led and consciously determined distance) and system a' (B-side-dominated and extraconsciously given distance). He then constructed a kind of neural system model composed of systems a and a', and thereby schematically presented a novel viewpoint on experiences of self and the outside world. The theory further illustrated how the hypothesized imbalance (Phantom Space shrinkage or diminished elasticity of system a') causes symptoms of schizophrenia, such as ego disturbances, auditory hallucinations, and other unspecific symptoms. This article then examines the clinical and theoretical implications of Yasunaga's psychiatric works. Phantom Space Theory is a nonstigmatizing account of schizophrenia because it does not presuppose personal or existential causes of psychosis. The relationship between Phantom Space Theory and dual-process theory is also explored.

Although clinical diagnosis of delusions is usually not difficult, defining delusions is more complicated. This study analyzes the concept of delusions, in particular persecutory delusions. Patients with persecutory delusions are convinced of others’ malicious intentions and are impervious to counterevidence. Conventionally, expression of intention is accepted at face value unless contradictory evidence is available. First-person authority regarding intention is respected in human society. Contemporary philosophy tends to limit the scope of first-person authority, but it cannot be eliminated. Persecutory delusions contravene first-person authority as one of the fundamental principles of daily life, even in the absence of malicious intention on the part of the patients. Two ways of denying others’ first-person authority are investigated. This study adds new insight to Manfred Spitzer’s formal definition of delusions.

This article investigates the history of the concept of mood-congruent delusions and the problems accompanying this concept. In the late nineteenth century, there were conflicting views regarding the relationship between the contents of an individual's delusional thought and his/her affective state. The differentiation between delusion-like ideas secondary to affective state and incomprehensible primary delusions was introduced in the early twentieth century; this differentiation is the origin of the present-day distinction between mood-congruent and -incongruent delusions. Although the themes of delusions are clearly described in the operational diagnostic criteria for mood-congruent psychotic symptoms, the concept of mood congruence inevitably involves ambiguity. This article argues that a dilemma between reliability and validity emerges when diagnosing mood-congruent (and -incongruent) psychotic symptoms.