Portrait of René Descartes 1893, by Franz Hals. Image taken from the Louvre in France.

The Descartes Dilemma

René Descartes was a French philosopher and mathematician alive during the 17th century. His contributions to philosophy and mathematics helped push the Western world into the scientific revolution. Descartes is the philosopher commonly attributed to developing what is termed the mind-body problem. However, he did not come up with the problem. Instead, Descartes's philosophy proposed a solution to the problem. Known for coining the phrase "I think, therefore, I am," Descartes developed a philosophy known as cartesian dualism--the argument that the mind and body are two separate entities. To understand Descartes's position, we must first understand what the mind-body problem is.

The Mind-Body Problem

Rene Descartes, Vintage engraving. From Popular France, 1869.
Rene Descartes vintage engraving. From Popular France, 1869.

Throughout day-to-day life, most people might not think about the relationship between their mind and body. However, our mind and body have an intimate connection, long discussed amongst philosophers. People have wondered if the mind and body are two distinct entities or a single entity as well as whether or not one is in charge of the other. These are the questions at the heart of the mind-body problem.

These questions have led curious minds to ask further questions, such as: if the mind and body are two distinct entities how do the two interact? What is the nature of the mind-body interaction? These questions have led to bigger philosophical discussions concerning the concept of the self. Throughout history, many different thinkers have pondered these questions. Different theories have tried to make sense of the mind-body relationship, however, the two most common answers to the mind-body discussion are known as dualism and monism.


I think; therefore I am - ancient French philosopher and mathematician René Descartes quote printed on grunge vintage cardboard
"I think; therefore I am," quote on cardboard. 

Dualism holds a clear distinction between the mental and physical states of humans. Human beings are believed to have two distinct parts, the body and the mind. The physical and mental states are separate entities in the dualist view. According to dualists, both the mental and physical exist, but on separate planes that are unable to interact. While the body can work with the mind, they are two distinguishable entities. 

This idea is also viewed in turns of voluntary and involuntary actions. The human body has a system that works independently of the mind. Breathing, heart beating, and digestion are all examples of involuntary actions. The mind, however, can initiate voluntary action. A good example of this dualist view is in cases where a person's body grows frail but their mind remains sharp (or visa versa).


Body and mind in balance - pictured as balanced balls on scale
Body and mind in balance are pictured as balanced balls on the scale.

In contrast to dualism, monists claim there is only one single reality that explains everything. The mind and body are not separated and are one entity. However, there are two main branches of monism: materialism and idealism. Materialism is the idea that only the physical or material world exists. In terms of the self, this means only the brain and the body exist. In this view, consciousness is only a function and is considered to be just something that the brain does. Idealism is the opposite of materialism. Idealists claim that nothing material exists, the only reality is the mind. According to this perspective, physical objects are a product of our mental capacities.

Descartes' Position

This image represents one of the most influential Enlightenment thinkers, that of Rene Descartes.
Famous Enlightenment philosopher, Rene Descartes.

Descartes was a dualist and one of the first philosophers to develop this theory. His answer to the mind-body problem he named Cartesian dualism. Cartesian is the Latin word for Descartes, so Cartesian dualism translates to Descartes's dualism. Descartes believed that the mind and body were two completely different entities and that they do interact with each other. 

According to Descartes, an important component of the body is that they have measurable characteristics in space. Matter is spatial, and has a material, measurable position. All physical entities have a height, depth, and length that is measurable. In contrast, mental entities are immeasurable.
Instead of spatial measurements, the mind has consciousness. Since the body's spatial dimensions define its characteristics, and the mind is not this way, Descartes claimed one cannot act upon the other. This is because it would be contradictory for the mind, which is not in space, to act on the body, which exists within space. Action on the body takes place in space, where the body is present.

Critics - Descartes Dilemma

Princess Elizabeth, Queen of Bohemia and Electress Palatine
Princess Elizabeth, Queen of Bohemia. Image credit National Gallery via Wikimedia Commons.

The Descartes Dilemma is that Descartes himself never proposed the mind-body problem. Instead, he provided a solution. Princess Elisabeth of Bohemia famously critiqued Descartes's idea. She suggested that if the soul or mind affects the body it must contact the body, and to contact the body would mean the mind is occupying some space. In critiquing Descartes's idea, critics thus came to the mind-body problem. Descartes's sharp distinction between the mind and body brought about the question of whether the mind and body were truly separate entities. While Descartes laid the groundwork for the mind-body problem, his philosophy and solution have proved not as clear-cut as he would have liked.


The difference in theories between monists and dualists shows how differently people have approached the mind-body connection and whether or not there is one. While there are philosophers who dedicated their lives to thinking and researching the mind-body problem, some people might wonder why this might even matter.

At its core, the mind-body problem is looking at the nature of reality and trying to find our place in it. This idea has larger implications for what it means to be alive. Thinking about this idea and encouraging others to do the same promotes self-reflection. Pursuing this further could benefit society in the future, but at the very least, the pursuit of knowledge is never a waste of time.

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