Immanuel Kant on Mental Disorders

 

 

 Dr.  Ruwan M Jayatunge, M.D. PhD

Immanuel Kant's exploration of mental disorders is extensively articulated in his later work, Anthropology from a Pragmatic Point of View (1798). Unlike the predominant medical or biological perspectives of his era, Kant adopted a pragmatic approach, emphasizing the impact of mental illness on an individual's cognitive and moral agency rather than merely its physiological origins.

His philosophy underscores the importance of self-understanding and resilience in the face of psychological challenges. For Kant, a sound mind is characterized by the harmonious functioning of the three faculties—cognition, feeling, and desire—under the guidance of reason. Disruption in this balance, where one faculty becomes dysfunctional or unruly, is what he identifies as the root of mental illness.

Kant's perspective on mental illness is a philosophical rather than solely a medical issue, emphasizing the mind's failure to adhere to its own logical and judgmental norms. He offers profound insights into the essence of mental disorders, suggesting that individuals bear some responsibility for their mental well-being, even as he recognizes that certain conditions may be hereditary or beyond cure.

Kant identifies the "only universal characteristic of madness" as the substitution of shared, rational reasoning with an individual's private logic. He categorizes mental pathologies through a tripartite framework encompassing cognition, feeling, and desire, distinguishing between weaknesses (deficiencies) and illnesses (active derangements). In his view, the philosopher, as an expert in reason, is best equipped to assess the nature of madness, which he sees fundamentally as a breakdown of rational thought.

Kant’s theory of mental disorder is a sophisticated philosophical framework defining mental illness as a breakdown of the conditions for objective experience (Frierson, 2009).  Kant argued that mental disorder is the transition from "common sense"   to a "private sense." For Kant, "common sense"   is a normative tool for testing the truth of our perceptions and judgments against the world. Kant defined a healthy mind not by the absence of biological disease, but by its normative functioning—specifically, its ability to align with the universal rules of logic and a shared social reality.

Kant explicitly stated that madness can be hereditary, referring to "germs of madness" that develop alongside physical reproduction. He believed certain physical states, such as issues with the digestive system or a naturally "melancholy" temperament, could make an individual susceptible to mental derangement. Kant argued that nature might provide the "predisposition" for illness, social life, and personal habits, which often act as the catalysts. He stated that societal pressure could break the natural balance of the mind’s faculties. Kant emphasized that even a sound intellect can fall into illness because human reason is fragile and depends on constant social communication to remain healthy.

Kant indicated a profound connection between mental illness and the historical evolution of society (Falcato, 2025). This indicates that Immanuel Kant did not view mental illness merely as a biological malfunction. Kant's assertion that humans possess an inherent inclination toward social interaction, or sociability, alongside a simultaneous tendency to seek isolation and act in self-interest, creates a psychological conflict.

As society progresses, it generates artificial needs that can lead to mental strain. Kant discussed issues such as hypochondria and mood disorders, arguing that culture plays a role in shaping and moralizing human behaviour. He suggested that human nature inherently resists societal constraints, which in turn exerts pressure on the mind. Kant posited that as society progresses towards greater civilization and intelligence, individuals become more susceptible to mental anxieties, a condition he referred to as hypochondria, as well as various cognitive disorders.

Van den Berg (2025) highlights that Kant's theory of mechanical explanation remains relevant and aligns with contemporary mechanistic paradigms.  It provides a robust philosophical framework for the current biological turn in psychiatry and neuroscience. Kant strongly believed that the mind must be studied through its physical manifestation. Mental health professionals today assert that mental disorders stem from dysfunctions within brain circuits. This is a direct application of the Kantian mechanical explanation.

Kant rejected the binary choice of viewing madness as either purely a spiritual/moral failing or purely a biological disease (Polianskii, 2023). However, Kant insisted that the symptom itself is a disorder of judgment and reason. Kant adopted a moderate stance: Madness is a medical problem in its origin (requiring a physician for the body), but it is a philosophical problem in its manifestation (requiring a rational approach for the mind).

Kant’s "tripartite psychology" identifies specific failures of the mind that mirror modern psychotic symptoms. For Kant, a healthy mind is one that successfully synthesizes sensory data into a coherent experience of reality (Annett, 2023). Therefore, "mental dysfunction" is not just behaving oddly, but a structural failure of cognition—the mind's inability to perform the necessary "synthesis" to construct a stable, shared reality. Kant argued that true mental illness (dysfunction) occurs when the mind steps outside the "bounds of sense"—producing thoughts that have no possible connection to objective experience.

Kant’s classification of mental illness extends beyond individual health into the realms of public order and legal accountability (Ferrara, 2022). Kant used mental illness to define the boundaries of legal agency. A person suffering from a "malady of the head" is classified as "incapable”, meaning they lose the legal standing to represent themselves in court or enter into contracts. Kant argued that because a mentally ill person is governed by a "private sense" rather than universal reason, their actions are not "free" in the moral sense. He emphasized that they cannot be punished for crimes in the same way as a rational citizen, as they lack the capacity to recognize the law they have broken.

Kant's work from 1798 serves as a pivotal link between the traditional, often supernatural interpretations of mental illness and the emerging framework of modern medical psychiatry. Kant should be seen as a forerunner of the trends in modern psychiatry (Tényi, 2019).  Kant was truly a visionary for his era. During his lifetime, mental illness was frequently seen as a result of demonic possession or a moral shortcoming. In such a rudimentary understanding of mental health, Kant's progressive views on the subject were remarkably advanced, reflecting a deeper insight into the complexities of the human mind.

  

References

Annett, N. (2023). The concept of mental dysfunction: A Kantian critique [Doctoral thesis, University of East Anglia]. UEA Digital Repository. https://ueaeprints.uea.ac.uk/95747/1/Final%20copy%20-%202023AnnettNBPhD.pdf

Falcato, A. (2025). Kant’s early diagnosis: The maladies of the head as a cultural phenomenon. Philosophy Today, 69(1), 131–147. doi.org.

Ferrara, I. (2022). The political dimension of pathology: Kantian mental illnesses between fragility, freedom, and imputation. Estudos Kantianos, 10(1), 119–138. doi.org.

Frierson, P. (2009). Kant on mental disorder: Part 1. An overview. History of Psychiatry, 20(3), 267–289. doi.org.

Polianskii, D. V. (2023). Kant's concept of madness, psychiatry and anti-psychiatry. SHS Web of Conferences, 161, 07007. doi.org.

Tényi T. (2019).  [Immanuel Kant's concept of mental disorders]. Psychiatr Hung. 2019;34(3):325-326. Hungarian. PMID: 31570664.

Van den Berg, H. (2025). Kant’s essentialism and mechanism and their relevance for present-day philosophy of psychiatry. European Journal for Philosophy of Science, 15(1), Article 7. doi.org.