Is Consciousness…Separate From The Body?
By: Narcis Marincat
Tags: Neuroscience, History Of Consciousness, Philosophy, Consciousness, Philosophy Of Mind

And as we touched on these milestones, we hinted at two basic rules of thumb for when, historically, the concept of consciousness experiences an upgrade:

When our understanding of the body changes — in particular the parts of the body that are thought to be part of the mind. For example, Galen’s idea that the brain contained four chambers with ‘animal spirits’ that transmitted the will of a soul which resided in the surrounding brain tissue came from experiments that increased his knowledge of human anatomy.

When new analogies to the human body appear. For example, Plato’s view that the body has three souls came from an analogy between the body and his new division of the state — like the state has three types of people, there are three souls.

In this post, we will discuss the ‘middle’ period in the history of consciousness, which properly starts with the French philosopher René Descartes (1596–1650).

Descartes, in the primitive, pre-Ray-Ban era.

Descartes managed to do two things that are of crucial importance to the present-day understanding of consciousness:

a). Be one of the first to use the term ‘consciousness’ in its modern sense.

As mentioned in the first part of this post, the term consciousness comes from the latin con- which means ‘with’, and -scio, which means ‘to know’, as in knowing together. And before the time of Descartes, people would use the term in a way that meant conscious with someone. As in, I was conscious with you of this blog post, which meant I knew together with you of this blog post. Descartes changed all that by using the term consciousness to mean one’s own mental processes.

b). Be the first to remove the soul from the physiological processes of the body, and think of the body as a machine.

Until Descartes, it was largely believed that the soul was the driving force behind all of the bodily processes as well as the cognitive ones, but Descartes lived in a time when the idea of the clockwork universe was getting a lot of traction, fueled by the works of Galileo and Kepler. This was the view that the universe functioned like a mechanical device ruled by mathematical laws. Descartes took this idea and applied it to the human body. He came to see the body as machine as well, that functioned based on cause-and-effect laws like the rest of the material world. In his view, the only thing that did not follow the same causal path as the rest of the universe did was the soul, and so he reasoned that it had to be made of a different substance then the material world. This was the basis of the so-called dualist philosophy of mind that was to be so influential, and continues to be into the modern day: The idea that the body and the mind are separate substances.

Interestingly, Descartes still held on to the view that the brain was filled with ‘animal spirits’, which Vesalius (who we mentioned in part I of this series) and other scholars had completely debunked decades prior. Descartes proposed that the soul communicated with the body via the brain’s pineal gland, which was suspended deep within the brain in a whirl of “animal spirits,” dancing and jigging “like a balloon captive above a fire”(1).This part of his theory didn’t get much support even in his day, but you can’t win ’em all.

For Descartes, light that reaches the retina stimulates the ‘animal spirits’ which travel through the optic nerves and activate the jigging pineal gland. Can’t get enough of this word…Jigging.

Descartes was reported to have kept a mechanical replica of his daughter with him wherever he went.

Now, did Descartes have any help in reaching his revolutionary conclusions? A little known fact about Descartes is that he was also part of the first generation to have around complex automata around him, or what we might call the granddaddy of robots. These were mechanical machines that would look and act like people or animals. In fact, there was a rumour going around that Descartes was actually a builder of automata, and had made a life-size, mechanical replica of his daughter, who had died when she was an infant (2). Descartes was reported to have kept this replica with him wherever he went, until eventually the crew of a ship he was sailing with found it in his lodgings. Terrified that what they had discovered was made with magic, the crew destroyed ‘the mechanical daughter’ and threw it overboard. Descartes died a few months after this supposed episode.

Whether or not this story is true, there is no doubt that Descartes was influenced by the idea of the clockwork universe and the existence of automata in his time to formulate his radical idea that the body was a machine. Even when he discusses how the soul influences the movements of the body via the pineal gland, he uses concepts derived from the mechanics of automata. For example, he states that when the pineal gland moves due to the influences of the soul, it opens and closes valves that are found on the walls of the ventricles, which in turn determines the flow of the animal spirits which contract or relax muscles (3).

And here, we find traces of the first rule of thumb for when the concept of consciousness changes, that we mentioned in the first part of this series:

The concept of consciousness changes when the analogies that are available to us for understanding the body change.

In this case, it was the analogy between the clockwork universe, automata and the human body that led to the idea that consciousness was purely psychological, and the body purely physical, which is the basis for the dualist philosophy of mind that still stands strong to this day.

Joseph Priestley believed that the mind arose from nervous tissue — specifically from the brain.

Not long after Descartes, Isaac Newton (1642–1727) published his work on the Universal Laws of Motion, which completely revolutionised the sciences, but it took about a hundred years for their consequences to be felt on the philosophy of mind, and one of the first scholars to draw a connection (if not the first) was the British polymath Joseph Priestley (1733–1804). Priestley recognised that by introducing the idea that forces that acted upon matter’s constituent parts, Newton had completely uprooted the concept of matter as it had been understood during Descartes’ time. Using the Newtonian principles of matter as foundation, Priestley announced that there was no need to separate the mind from solid matter at all — they were two sides of the same coin. Priestley had an uncannily modern view of the origins of consciousness: He stated that “Thought is a property of the nervous system, or rather of the brain.” (4) That’s a noteworthy statement to be making 250 years ago! Since damage to the brain leads to deficits in mental faculties, it seemed to him a rational conclusion.

Consciousness was not the only topic that Priestley was a visionary in.

In Priestley’s time, it was common to think of the body as somehow hindering the abilities of the mind, which many still equated with the soul. The standard view in that age was that once the soul was free of the body, it would finally be free of earthly limitations. But Priestley saw that as nonsense — there was no account of the mind without the matter that supports it. Even though he was definitely ahead of his time, in Priestley, we see that it was possible to have quite a modern account of the mind in the 18th century. And much of that possibility was owed to the second rule of thumb that we mentioned in Part I of this series:

The concept of consciousness changes when the knowledge that we have of the human body changes.

In this case, it was knowledge that existed about matter in general, which invariably included the human body, that helped Priestley reach his conclusion. This new information came from Newton’s work, as well as from some of Priestley’s contemporaries, including R.J. Boscovich (1711–1787), who was regarded as one of the fathers of modern atom theory, and spoke about forces operating between ‘points of matter’ that made up the entire solid universe. (4) Priestley drew from these works to ascertain that the mind (i.e. consciousness) is a product of matter organized in particular way — specifically, in the way we find in the human nervous tissue.

Despite Priestley’s insights, the development of the concept of consciousness does not follow a linear path, and there were many in his time and beyond that still shared some of the beliefs of the mind that went back to ventricular psychology. But in the 18th century, we begin to see such bursts of intellect shedding light on what was to become standard understanding in the 20th century concept of consciousness.

Still, these were early days. Consciousness had yet to evolve from a relatively ‘fresh’ term with its origins in Cartesian thought a century prior, and mind and soul were still the words most used to denote the processes that we nowadays attribute to consciousness. Moreover, many discoveries were yet to be made before the foundation for our modern view of consciousness would be complete. This included the cell theory — the theory that all living things are made up of cells and the products that they create. We will tackle some of these discoveries and how they influenced the definition of consciousness in Part III of this series.