Problems with Cartesian Dualism (Philosophical perspective)

In this guide, we will discuss the Problems with Cartesian Dualism philosophers consider when talking about the mind and body interaction. 

Problems with Cartesian Dualism

Philosophers have dedicated their time to discuss the problems with cartesian dualism, one of them being the problem of interactionism that we will address later on. However, we can say that many have considered cartesian dualism to lack consistency when explaining how consciousness affects physical reality, the inability to explain how things in the mind can interact with the body. 

Cartesian Dualism is known thanks to Rene Decartes who was born in France and was a mathematician, scientist and philosopher. He is famously known for his principle of ‘Cogito Ergo Sum’ which means, ‘I think, therefore, I exist’. Consequently, he believed we should doubt everything but in the process, he acknowledged the doubting which involves thinking, subsequently implies existing. 

Having established his existence, he wanted to go further by investigating this basic truth, knowing what makes it indubitable. He eventually concludes that what makes this free of doubt is the fact that “if the truth affirmed by the proposition is perceived clearly and distinctly, then the proposition must be true (Mohammed, 2012).”

Dualism and Interactionism

When Decartes does the conscious exercise and concludes that he possesses a mind, which is his thinking being and is distinct from his body. Consequently, he argues there are two distinct categories or aspects inherent to human beings, a mental substance and a material substance. Additionally, the two distinct substances can exist independent of each other, giving birth to Cartesian Dualism. 

Having established the existence of the mind separate from the body, Decartes starts wondering how they seem to interact even if he argues they are distinct substances. He argues that for instance if we feel pain, the mind reacts to what the body is feeling and vice versa. But, the question is, How does the mind-body interaction take place? How can two different substances in nature affect each other?

Descartes then argues that this interaction takes place at the ‘pineal gland’ which is located in the innermost part of the brain. However, we know now that the answer isn’t that simple and many theories have surfaced as better alternatives to Decartes’ pineal gland theory such as materialism, idealism, occasionalism, epiphenomenalism, etc.


Through materialism, we find how people can be described as physical entities that have physical properties and physical mental states.

Materialism is said to be best exemplified by behaviourism where the central argument is that the mind somehow can be reduced to behaviour. For instance, Skinner explains behaviour as the action of an organism upon the physical world. 

Philosophical behaviourists argue that inner states can always be eliminated, so as indicated by Mohammed (2012), “Essentially, when we ascribe a mental state to someone, what we are doing is not to infer the existence of some ghostly inner state on this basis of our observation of subject behaviour, but to characterize and assess just the observable. The behaviour of the subject.”

However, behaviourists have been criticized because they are said to leave out internal processes such as cognitions that can’t be seen.


A modified form of a materialistic theory of the mind arises as a result of the problems of behaviourism, this is known as epiphenomenalism. This theory argues that our cognitions, feelings, etc., are not just physical states in our brain but are said to be the sequence of physical occurrences.

Epiphenomenalism also argues that the significant events in the world are only those of matter in motion and they argue that every time there is any sort of physical activity in our brain (i.e. thoughts) is caused by material events.  Even if epiphenomenalism may help reduce the gap that behaviourists have opened, it fails to eliminate all of the problems. 


This theory is opposed to materialism in the sense that insists on how the mental and physical are real but the mind is superior. However, it becomes a reductionist theory when other idealists insist that only the mind is real and others believe that physical events are responsible for our behaviour (i.e. drugs). 

Problems for dualism

Mental states are said to have two main properties such as subjectivity or privileged access and intentionality. Physical properties of objects are observable at times but physical objects can be accessed by anyone. However, people have privileged access to their mental states that can’t be shared. 

As indicated by, “Physical objects are spatio-temporal, and bear spatio-temporal and causal relations to each other. Mental states seem to have causal powers, but they also possess the mysterious property of intentionality – being about other things – including things like Zeus and the square root of minus one, which does not exist.”

Subsequently, the nature of the mental states (or the mental itself) is said to be elusive.

Many philosophers and thinkers have referred to the phrase ‘ghost in a machine’ to talk about how dualists conceive the mind.

The Unity of the mind

Whether you conceive the mind as a substance or group of properties, the same problem arises when explaining the nature of the unity of the mind which is immaterial. Cartesian dualists don’t seem to explain clearly the relationship between the different elements of the group of properties that bind the mind and body. 

Unity and bundle dualism

If the mind is a ‘group’ of properties then if there is no mental substance to unite them, there needs to be an explanation as to how it can constitute its unity. The only explanation seems to argue a primitive relation of co-consciousness in which the elements stand to each other. 

Unity and Substance Dualism

The problem is how to explain what kind of immaterial thing a substance is, such that its presence explains the unity of the mind. The answer can be divided into three kinds as explained on

  • The ‘ectoplasm’ account. The immaterial substance is a kind of immaterial stuff and there seem to be two problems with this approach. The first problem is characterizing ‘ectoplasm’ as ‘stuff’ and it means it is a structure of its own over and above mental properties. However, it remains a mystery how this kind of ‘stuff’ holds an explanation on supporting consciousness as it is why the ordinary matter should.
  • The ‘consciousness’ account. This view proposed the consciousness as a substance and as such, it is allowed to be an immaterial substance whose nature is over and above the kinds of state we could regard as mental but the consciousness account doesn’t, which seems to be Decarte’s point of view. “The most obvious objection to this theory is that it does not allow the subject to exist when unconscious.”
  • The ‘no-analysis’ account. This view proposed that it is a mistake to present any analysis. Some argue that even the ‘consciousness’ account is an attempt to explain what the immaterial self is ‘made of’. 

Why is this blog about Problems with Cartesian Dualism important?

The problem with cartesian dualism in terms of the mind-body problem leaves more unanswered questions than answers such as what seems to be the relationship between the mind and body and how can we explain their interaction if they are said to be two independent substances that still affect each other. 

Another question that we can consider is what is the relationship between mental and physical properties? We have discussed some of them throughout this article but there is still an ongoing debate related to the theory of the mind proposed by Cartesian Dualism since physical properties can be seen (most of them) but it gets more complicated when we talk about mental states. 

Please feel free to leave any comments or thoughts about the content of this article!

Frequently Asked Questions (FAQs) about Problems with Cartesian Dualism

What is the mind body problem and why is it a problem?

The mind-body problem exists because we are inclined to include the mental processes conscious organisms have to have a better understanding of the world and our behaviour. Many have argued that everything that happens in our mind depends or is correlated to how our brain works and functions.  

Why is the mind body problem a problem in philosophy?

The mind-body problem has become a problem in philosophy since philosophers are concerned about the extent to which the mind and the body are separate entities or the same thing. Many philosophers have argued that the mind is related (or responsible) to mental processes, thought and consciousness. However, the body is seen as a physical entity which includes the brain, neural activity and how it is structured.

Is Cartesian dualism plausible?

Cartesian dualism is said to be one of the most plausible theories of the mind. Cartesian dualism or interactionism, how it is known today, argues that physical and/or material events can cause or are responsible for immaterial events and immaterial events can also cause material.

What is the theory of dualism?

The theory of dualism argues that the mental and the physical, the mind and the body or the mind and the brain, are somehow two different entities or two distinct categories of things. In the philosophy of mind, we find dualism as the theory usually starts when assuming the reality of the physical world, and how there are arguments against considering the mind as simply part of that world.

What is the hard problem of consciousness and why is it so hard?

The hard problem of consciousness is the problem of explaining why any physical state is conscious rather than nonconscious. It is the problem of explaining why there is “something it is like” for a subject in conscious experience, why conscious mental states “light up” and directly appear to the subject.

References “Dualism”

Mohammed, A.A. (2012) A Critique of Descartes’ Mind-Body Dualism. Kritique Vol. Six. Number one. Pages 95-112. Retrieved from 

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