The Mind Body Debate in Psychology

“Cogito, ergo sum.” 

Do you know who said this? 

You might be able to answer this if I tell you the English translation: “I think, therefore I am.” 

This phrase was made famous by René Descartes, a French philosopher who lived in the 1600s. Why am I bringing up his work today? Descartes is a major player in the world of the Mind Body Debate. The debate tries to answer the question: are the mind and body separate or one in the same? 

This video will define the main types of dualism, monism, and how these ideas contribute to the Mind Body Debate. I’ll also briefly touch on why this debate is so important today, both in everyday life and when we look at larger ideas. 

Let’s get started. 

What Is Dualism? 

I’m going to start by explaining dualism. Descartes was a dualist. He believed that the mind and body were separate entities. The mind and the body work together, but they remain separate. 

Substance Dualism 

Descartes’ ideas (or Cartesian dualism) is also known as substance dualism. Substance dualism completely separates the mental from the physical. Descartes also believed that humans were the only creatures with a physical and mental existence that worked together. 

Property Dualism

Descartes existed in the 1600s – we’ve come a long way since then. Other forms of dualism have entered this overall debate. The most notable is property dualism. Property dualism somewhat blends the idea of monism and dualism. This theory states that there is just one type of substance: the physical substance. Physical substances, however, have physical and mental properties. 

What Is Monism? 

Dualism is not the only approach to the Mind Body Debate. Many believe that the mind and the body are not separate. Mental and physical worlds are not separate. They exist together. These ideas are called Monism. 

There are two approaches to monism. One is materialism. Materialism is the idea that all things are a part of the physical world. Our thoughts and cognitive processes are simply functions of the physical brain that exists in our heads. Without a working mind, these mental processes simply wouldn’t exist. This approach is very similar to the ideas of physicalism. 

But what if everything existed only in the mental world? That is the idea behind phenomenalism. Phenomenalism (or Subjective Idealism) states that everything, including the body we claim to inhabit, is a result of mental processes. 

How Does This Fit Into Psychology? 

If you’ve kept up with my recent videos, you know that I’ve been talking a lot about how the mind works. When I say “mind,” I mean the mental processes of thinking. The “brain” refers to the physical brain existing inside our heads. 

What do behaviorists and social psychologists have to say about the Mind-Body debate? It’s not something that is up for too much debate. Behaviorists and similar experts are primarily concerned with observations, data, and studies. It’s not possible to get data and observe the mind separate from the body. The solution is either to ignore the mind entirely or lump it together with the body. 

Why Is This Debate Important? 

You might find yourself wondering why philosophers still think about the Mind Body Debate. Why do we care whether our minds and bodies are the same? 

Philosophy is fun!

First of all, it is fun to think about. Let’s say your name is Jake. That is the name assigned to your physical body that you inhabit. But are you Jake?

 On the one hand, if it’s true that you are Jake, you can’t not be Jake, right? That is something that dualists can agree on. Here’s where things get tricky. It could be possible for Jake to exist without your body existing. (Think of the movie Freaky Friday, or a situation in which you are placed into another body.) 

So…it’s possible for “you” to exist without “Jake” existing. You can not be Jake. 

That crumbles the statement that I made earlier: “If it’s true that you are Jake, you can’t not be Jake.” But you can not be Jake. In conclusion…you’re not Jake? 


If you want to see how philosophy can turn your head upside down, this is a great place to start. 

Are we immortal? 

When educators begin to explain deductive reasoning and other basic terms in psychology, they often start with a simple truth: all humans are mortal. 

But are we? 

Depending on the argument that you choose to believe about the mind and the body, your answer could vary. In the physicalist or materialist world, the answer is easy. You’re mortal. When your body expires, the mind expires with it. 

If you believe the body and mind to be separate, or you believe that everything stems from the mind, the answer becomes more tricky…


Not all implications of the Mind Body Debate have to do with big topics. You can take religion and mortality out of the picture and still have a reason for the Mind Body debate. One such reason is in the realm of mental health. 

The Western world holds a reductive physicalist view. Western healthcare professionals believe that everything can be traced back to functions of our brain. Hormones, neurotransmitters, and other chemicals can explain it all. 

“It” includes mental illnesses or conditions, including depression or PTSD. By assessing and adjusting a person’s brain chemistry, the reductive physicalist approach implies it is possible to treat these conditions. 

On the one hand, you may know someone who has been able to treat mental conditions using antidepressants or similar medications. On the other hand, you may know people who have treated similar symptoms without medication prescribed by modern scientists. You may know someone that swears by Acupuncture, Reiki, or other types of healing that cannot be explained by modern science.

Great debates in philosophy, like the Mind Body debate, aren’t just ideas that can only be discussed and applied in a classroom. Clearly, these debates could explain many things in the world around us.


Theodore T.

Theodore is a professional psychology educator with over 10 years of experience creating educational content on the internet. PracticalPsychology started as a helpful collection of psychological articles to help other students, which has expanded to a Youtube channel with over 2,000,000 subscribers and an online website with 500+ posts.