Austin LamAustin Lam is a medical student at the University of Toronto.


The importance of mental health has rightly been emphasized in recent times. The stigma surrounding mental illness ought to be dispelled. However, I wish to take a closer examination at the conceptual elephant in the room: the mind-body problem — a philosophical issue that strikes to the core of continuing disparities between how the healthcare apparatus as a whole addresses “mental” versus “physical” health conditions.

As medical historian Roy Porter pointed out in his book The Greatest Benefit to Mankind: A Medical History of Humanity (1997): “psychiatry lacks unity and remains hostage to the mind-body problem, buffeted back and forth between psychological and physical definitions of its object and its techniques.” This was a prescient remark. In 2018, the editor-in-chief of Dialogues in Clinical Neuroscience, Florence Thibaut highlighted the mind-body problem and the challenge that it poses for psychiatry: “recent advances in neuroscience make it more and more difficult to draw a precise line between neurological disorders (considered to be ‘structural brain disorders’) and psychiatric disorders (considered to be ‘functional brain disorders’).”

To begin, let’s analyze the statement — Mental health is health. 

A first layer of analysis will recognize that this is a performative utterance (see J.L. Austin) expressed to reduce stigma and change societal attitudes.

When analyzed deeper, the statement mental health is health carries within itself the longstanding philosophical mind-body problem, formulated as (according to the Stanford Encyclopedia of Philosophy):

“What is the relationship between mind and body? Or alternatively: what is the relationship between mental properties and physical properties?”

One influential response came from philosopher René Descartes. This position has been called substance dualism, i.e., there are two distinct types of things — physical and mental. Historically, as sociologist Andrew Scull has written in his book Madness: A Very Short Introduction (2011) Descartes’ dualism was adopted by the medical profession as part of “the medical profession’s defence of its claim to jurisdiction over the management of the mad.” The reasoning at the time was that the mind — identical to the immortal soul — was incapable of error, so any pathology must lie in the material, mortal body.

Roy Porter, in The Greatest Benefit to Mankind, wrote a similar account:

“The implications of Cartesianism for insanity were momentous… Though Descartes was no materialist, his writings encouraged a search for the site of madness within the organism, indeed within the brain.”

And Scull underscored in Madness that “Until well into the second half of the 19th century, medical men would rehearse these arguments, which rapidly became the ruling orthodoxy in their midst.” And so the stage was set for someone like psychiatrist and neurologist Wilhelm Griesinger (1817-1868) to declare that “mental illnesses are brain diseases” though he did recognize a multifactorial aetiology.

Griesinger’s insistence that “every mental disease is rooted in brain disease” is echoed perhaps louder than ever in today’s medical/scientific environment, such as in the Research Domain Criteria (RDoC). The problem is that conceptually-loaded terms are played with fast and loose, namely, mind and brain and their corresponding terms — as demonstrated in the RDoC’s framing of mental disorders as disorders of brain circuits (Jerome Wakefield has criticized the RDoC as Wittgenstein’s nightmare). Against the trend towards reducing the mind to the brain, Scull noted in 2011 that “A simplistic biological reductionism increasingly became the dominant psychiatric paradigm.” Philosopher Jerry Fodor offered sharp criticism of the underlying assumptions, asking “Why, why, does everyone go on so about the brain?”

The WPA-Lancet Psychiatry Commission on the Future of Psychiatry spoke of the integration of a contemporary neuroscience with traditions of psychotherapy and social psychiatry. I postulate that this integration will be an impossible task without proper philosophical underpinnings.

What are some ways forward?

Philosopher Donald Davidson proposed a theory called Anomalous Monism, which concerns “the physical status of mental events, and the relation between these issues.”

Without getting into the details of Davidson’s argument (see SEP article), I would like to highlight that his theory supports a position called predicate dualism, i.e., “the theory that psychological or mentalistic predicates are (a) essential for a full description of the world and (b) are not reducible to physicalistic predicates.” In other words, there are events in the world. These events can be described using mental predicates or physical predicates (predicate dualism). Importantly, the events are not “mental” or “physical” per se (ontological monism).

For instance, schizophrenia can be described as a disorder of a given set of brain circuits; in this sense, it is a physical issue. Equally, schizophrenia can be described mentally in a phenomenology of schizophrenia, seeing schizophrenia as a disorder of consciousness and self-experience. The term “schizophrenia” refers to one set of events, which can be described “mentally” or “physically.” While the ontology is identical, mental predicates/properties are not reducible to physical predicates/properties. In this sense, the mind supervenes on the brain but is not reducible to the brain (or more properly in anomalous monism, irreducible to base-level physical properties, such as those in physics).

What are the implications?

Mental health professionals, including psychiatrists, are likely working with an additional and distinct set of predicates, such as in a phenomenology of psychopathology, i.e., a structure of meanings in beliefs, thoughts, and feelings. As such, this set of predicates may require going beyond what has been conventionally defined as the domain of medicine/natural sciences, namely, to the humanities and social sciences. While the body and its organs can be described using physical predicates, there are no mental predicates that apply. On the other hand, psychiatry is dealing with a set of events that can be given either/both mental and physical predicates. And meanings as manifested in conscious life or someone’s stream of consciousness reside in the realm of mental predicates, not physical predicates.

So, given that meanings are involved a priori, it may be that the necessary language to meet this challenge is one that draws from anthropology, sociology, history, philosophy, and other areas. And it may be that this is not merely useful, but is demanded by what psychiatry is constitutively where meanings are involved a priori.

All of this speaks to how we think about mental health and physical health. Increasingly, there is a desire to find out how these two interrelate and how psychiatric expertise can be better integrated in mainstream medicine.

To paraphrase Andrew Scull, philosophical investigations into the mind-body problem have very real consequences, such as in how mental disorders are conceptualized, diagnosed, and treated.