Mental Illness as Metaphor: A Logical Fallacy

How we define the term "mental illness" matters.

Posted Jul 04, 2018

It is frequently asserted by those associated with anti-psychiatry that "mental illness" is nothing more than a metaphor, a figure of speech, used to describe socially deviant persons. Since there exist no biological tests for mental illness, it is alleged that mental illness is a merely a myth whose only purpose is to justify psychiatric coercion. First espoused by the psychiatrist Thomas Szasz in his classic 1961 book The Myth of Mental Illness and 1960 paper of the same title, this is an argument I am well familiar with and supported for quite a few years.

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Source: Public Domain

Yet, in the face of the clinical realities of psychotherapy practice and emergency room psychiatry, I began to question the veracity of the Szaszian position on mental illness. While it is easy to endorse such a view while sitting in a university lecture hall or even working with mildly disturbed people in outpatient psychotherapy, it becomes much more difficult to do so when evaluating the incoherent or catatonic patient in a psychiatric emergency room.

Most writings on mental illness begin with the assumption that an entity known as "mental illness" exists and follow from that assumption. Certainly, what "mental illness" is and what it means bears enormous weight in consideration of how to see the mentally disturbed person and how to help him. Essentially everything that is done in psychiatry and psychotherapy stems from the conceptualization of mental illness.

The question "What is mental illness?" can only be answered once the concept of "disease" is properly defined. If mental illness is a category of disease, as commonly insisted and officially classified, then we must first clarify the meaning of disease.

In his writings spanning a period of more than 50 years, Szasz frequently referenced the pioneering German pathologist Rudolf Virchow to support his claim about the myth of mental illness. Virchow, known as "the father of modern pathology," is perhaps best known for his work on the cellular basis of disease. Szasz's interpretation of Virchow concludes that since mental illness cannot be demonstrated at autopsy, it cannot be legitimately classified as disease.

But what did Virchow really say? Szasz's former student Ronald Pies, now a professor of psychiatry at The State University of New York (SUNY) Upstate and Tufts, asserts that Szasz and Virchow are in conflict on one vital, and consequential, point. For Szasz (1974, p. 99), "Every 'ordinary' illness that persons have, cadavers also have." But for Virchow, illness or disease is always a condition of the living person; and whereas bodily lesions may persist for some time after death, "the illness of the person is terminated." (Pies, 1979)

If disease is of the person and not merely the body, as Virchow implies, then pathophysiological lesion is but one way to identify disease. Some definitions of disease place little emphasis on cellular pathology and much greater focus on suffering, impairment, and incapacity. Surely, there exist a whole host of medical conditions readily accepted as diseases for which no underlying pathophysiological mechanism has been identified.

A second, and related, claim by Szasz is that mental illness is a metaphor. Szasz (1998) writes, "Individuals with mental diseases (bad behaviors), like societies with economic diseases (bad fiscal policies), are metaphorically sick." An examination of this claim reveals that it, too, rests on flawed logical and epistemological assumptions.

When Szasz insists that mental illness is merely a metaphor, he equates metaphoricity with falsity. That is, when Szasz says that schizophrenia, for example, is metaphorical illness, he seems to think that it has no ontological or real-world referent. To Szasz, schizophrenia is not simply non-disease; it's not "a thing" at all. Hallucinations, paranoia, and catatonia are not genuine experiences but claims made by the patient in a complex form of game-playing (Szasz, 1965). To equate metaphoricity with falsity is to insist—rather erroneously—that a metaphor cannot accurately depict the state of affairs in the world.

In a forthcoming book chapter, Pies puts it this way:

"When we say that "Night's curtain fell upon the village," we may indeed be speaking metaphorically, but not falsely—assuming that it did actually get dark in the village. Similarly, even if we were speaking metaphorically in saying, "Joe suffers from mental illness"—i.e., inviting the listener to entertain some sort of implied "comparison"—it would not follow that we were making a false statement, or one without ontological reference. Joe might be suffering quite profoundly in the realm of the "mental."…Joe would not be rendered "metaphorically sick" merely because we used a metaphor to describe his condition—he would be actually sick!"

Furthermore, Szasz's conceptualization of mental illness and brain disease as mutually exclusive categories deviates from the medical reality. Szasz frequently asserted that once pathology is discovered, the entity ceases being a mental disease and instead becomes a neurological disease. Thus, he claims, it follows that there could be no such thing as mental illness.

However, this assertion rests on the faulty assumption that mental disease and brain disease are disjunctive categories. Just as some mental illnesses, such as schizophrenia, may be considered "brain diseases," some brain diseases–like Alzheimer's disease–may manifest as "mental illness." Mental illness and neurological disease are complementary, not contradictory, terms.

Given this philosophical analysis of Szasz's dual claims regarding the meaning of disease and metaphoricity, it becomes apparent that his conclusions regarding the nature of mental illness follow from untenable assumptions.

This is not to say that Szasz's other positions are necessarily illegitimate or philosophically unsound. Szasz wrote much of value on the danger of psychiatric hegemony, the relationship between psychiatry and the state, and the use of psychiatric diagnosis as a political and interpersonal weapon. He also advanced his own variant of psychoanalysis focusing on the autonomy of the patient in the therapeutic arrangement (see Szasz, 1965).

I submit that one could simultaneously accept that mental illness is literal disease and believe that the best way to treat it is via an approach that maximizes autonomy and shuns paternalism. The goal of any ethical psychotherapy is to improve the patient's sense of self-determination and free him from the constraints imposed by his symptoms. This is not rendered impossible by accepting the fact that mental illness is bona fide disease, nor does it conflict with a biopsychosocial model of human psychology.

What Szasz offered psychiatry was much needed in the 1960s when false commitment was still common, state hospitals were overcrowded, and the civil rights of psychiatric patients were frequently denied. But a careful consideration of his basic premise about mental illness and its meaning reveals logical fallacy.

Acknowledgment: My thanks to Ronald Pies, M.D., for sending me his upcoming book chapter and for his helpful comments in review of aspects of this article.


Pies, R. (1979). On myths and countermyths: More on Szaszian fallacies. Archives of General Psychiatry, 36(2), 139-144.

Pies, R. (in press). Thomas Szasz and the language of mental illness [Book chapter].

Szasz, T. S. (1965). The ethics of psychoanalysis: The theory and method of autonomous psychotherapy. New York, NY: Basic Books.

Szasz, T. S. (1974). The second sin. Garden City, NY: Anchor Books.

Szasz, T. S. (1998). Thomas Szasz's summary statement and manifesto. Retrieved from

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