When psychology was born in the late 19th century, there was already a lot of talk about something called the mind. In fact, in many aspects the psychological theories and methodologies used by the first psychologists were based precisely on what at that historical moment was understood as “psyche” .

In a way, psychology relied on positions that are not so much scientific as philosophical, and that had much to do with a doctrine known as dualism .

What is dualism?

Dualism is a philosophical current according to which there is a fundamental division between body and mind . Thus, while the body is material, the mind is described as a disembodied entity, whose nature is independent of the body and which therefore does not depend on the body for its existence.

Dualism creates a frame of reference that is widely used by various religions, because it opens up the possibility of the existence of a spiritual life outside the body. However, this doctrine is not simply religious, and it has had a very important influence on psychology, as we will see.

Variants of dualism

Ideas and beliefs based on dualism are not always easy to detect and can sometimes be very subtle. In fact, it is very frequent that people who in principle claim not to believe in the existence of a spiritual dimension speak of the mind as if it were independent of the body. This is not surprising, because the idea that our consciousness is one thing and everything we can see and feel through the senses (including our body) is another is very intuitive.

That is why it is possible to distinguish between different types of dualism . Although they are all based on the idea that body and mind are independent realities, the way in which they are expressed differs. These are the main and most influential ones in the West.

Platonic Dualism

One of the most developed and ancient forms of dualism is that of the Greek philosopher Plato, closely related to his theory of the world of ideas. This thinker believed that the body is the prison of the soul , which in its passage through mortal life is limited and aspires to return to the immaterial place from which it came through the search for knowledge and truth.

Later, the philosopher Avicenna continued to develop a dualism similar to Plato’s , and identified the soul as the “I”.

Cartesian Dualism

That of French philosopher René Descartes is the type of dualism that has most directly influenced psychology and neuroscience. Descartes believed that the soul communicated with the body through the pineal gland, and that the latter is virtually indistinguishable from a machine . In fact, for this thinker an organism could be compared to the irrigation system: the brain made a substance travel through the nerves to contract the muscles.

Dualism in neuroscience

Although modern science discards the concept of soul to explain how the nervous system works, there are still reasonings that can be considered transformations of dualism. For example, the idea that consciousness or decision-making belongs to a specific entity located in a specific area of the brain is very reminiscent of the myth of the “ghost in the machine” , that is, of a kind of autonomous entity that lives cloistered in the brain and uses it as a set of buttons and machines that it can control.

The problems of dualism

Although dualism is a popular way of thinking when talking about the nature of the mind, in recent centuries it has lost its popularity in the scientific and philosophical fields. This is partly because it is a philosophical current that raises many more questions than it answers .

If our actions and our consciousness are explained by the existence of a soul within our body… How can a disembodied entity express itself only through a body and not through anything, given that the immaterial being cannot exist in time and space? How is it possible to affirm that something immaterial exists within us if the immaterial is defined as being outside our capacity to study it?

Their role in the birth of psychology

The 19th century was a historical cover which in Western countries was marked by the rejection of dualism and the triumph of the idea that the mind is not something independent of the body. That is, the materialistic monism was assumed, according to which everything related to the psyche are expressions of the functioning of an organism.

However, in the world of psychology this idea was not always acted upon, partly because it is easy to fall into dualism and partly because of inexperience, as it has no precedent in psychological research.

For example, although Sigmund Freud declared himself an atheist and despised dualism, in practice his theories were based on a metaphysics so marked that it was difficult to distinguish his ideas from those of a person who believed in souls.

Similarly, most early experimental psychologists relied on the introspective method , accepting the idea that the mind is something that can best be studied “from within”, as if inside someone’s head there is someone capable of looking up and describing what he sees in a neutral way (since mental phenomena would be something like what happens in the machine that works independently of oneself).Furthermore, other figures in the history of psychology refused to rule out dualism : for example, William James and Carl Jung.

In any case, dualism continues to be a route of thought to which we tend to resort automatically , regardless of the conclusions we have reached through reflection on the nature of the mind. It may at some point disappear completely from the world of research, but outside it it is unlikely to do so.