A Brief History of Consciousness
Pre-Scientific View
What we now call consciousness is comprised of many different prior terms and concepts. Early philosophers and religious doctrines did not explicitly use the term consciousness in their writings, however they explored the questions that set the framework for our modern understanding of consciousness using terms like 'soul,' 'the essence,' and 'the spirit.' Historically these terms have shifted over time, and an understanding of how they informed our present view of consciousness is important to understanding it as a whole.
In ancient India, consciousness was seen something that could be channeled. It was viewed as the human soul or spirit; it was the essence of the inner being. The Taoists of ancient China shared a similar view on consciousness and believed it to be something one could take control of and use to mediate their own involuntary internal states.
In ancient Greece, Pythagoras, Democritus, and Socrates laid the basis of our Western perception of consciousness, and following these great philosophers came Plato, who believed “the world of ideas itself is just as real as the world of objects, and that it is through ideas that humanity attains consciousness.” Like Pythagoras, Plato also believed consciousness was a key element to a divine human soul that that culminates within the body and is expelled after death. These ancient religions and philosophers all had one thing in common: they viewed consciousness as a form of the human soul, something that exists within the human body, not as a component of it. They saw it as something liquid. Something palpable, representing an element to our existence that is absent in lesser beings. They saw it as the part that lived on when mortal body failed.
In the middle ages, occult scientists dominated the endeavors for identifying consciousness. These occultists attempted to identify the soul through nontraditional means, such as conjuring and mystical alchemy. One such occultist, Paracelsus, believed that consciousness in the form of ‘spiritual essence’ extended beyond humans to cover all animals, plants, AND inanimate objects. Animism is the “belief that a supernatural power organizes and animates the material universe.” Though these medieval investigators attempted to associate a supernatural power with our consciousness, their lack of reliable empirical evidence called their findings into question when the renaissance began.
One of the most famous philosophers, Rene Descartes, was one of the initial investigators to refute the findings of the occultists. It is he who gave rise to the idea that we can only really be sure of our own existence through our own consciousness. He summarizes this concept so elegantly with his widely known phrase “I think therefore I am.” Descartes also developed a view of the soul and body similar to that of the ancient religions and philosophers. Descartes saw a division between consciousness and body, both made of a substance, but one that was physical and one that was spiritual.
Around the same time as Descartes, so too began the work of Gottfried Willhelm Leibnitz. Leibnitz had an interesting way of viewing consciousness as comprised of evolving units called Monads. Leibnitz’s Monads were indivisible, fundamental units of consciousness, that could behave in different ways based on their abilities. For example, in the lowest monads “everything is obscure and confused, resembling sleep,” and in a higher level monad, as within humanity, “consciousness attains a state of apperception -- a reflexive knowledge of the self.” Leibnitz believed we are all comprised of these Monads with varying degrees of consciousness, as are all things from “inorganic matter to God.”
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Another important philosopher who lived slightly after the time of Leibnitz and Descartes was Bishop George Berkeley. Berkeley was a strict idealist and supported the idea that our consciousness served as a mere integration system for our perception of the world around us. Berkely made the case that “the external physical world is for all we know a figment of our imagination,” and because of this, the only thing we ever truly experience are the perceptions, thoughts, and feelings concocted by our own consciousness.
Scientific View
Philosophy, as an organized field, long precedes Neuroscience. Ancient Greek philosophers did not assign much purpose to the human brain, thinking instead that the heart housed all important functions. Early investigations into brain function did exist, but the widespread intellectual investment into studying the brain did not come until much later.
One of the earliest of these investigations was done in 100 b.c.e by a Greek physician named Galen who, after practicing medicine for some time, wholly insisted that the brain housed many important functions.
An almost exclusively anatomical appraisal of the brain was made between the time of Galen until around 1000 c.e. when several renowned Islamic Surgeons, Ammar ibn Ali, Alhazen, and Al-Zahrawi, made several advancements into neuroscientific inquiry such as removal of cataracts, analysis of the lens structure of the eye, and surgical treatments for neurological disorders.
500 years later, during the renaissance, Leonardo da Vinci produced a wax cast of human ventricles. Following his successful modeling, renaissance scientists like Nicolo Massa and Constanzo Varolio discovered other important brain components like cerebrospinal fluid and the brainstem. During the renaissance, many writings on brain structure and function began to appear.
In the centuries that follow, exponential growth is seen in publications regarding the brain. In 1664, Thomas Willis published “The Anatomy of the Brain,” which introduced the term neurology for the first time. In 1837, a man named Jan Evangelista Purkinje imaged a Neuron for the first time, and identified it as the basic cell unit within the brain. In 1932, Edgar Douglas Adrian and Charles S. Sherrington were awarded a Nobel Prize for their discoveries in the functions of neurons. All of these early advances in brain research were performed within the scope of Psychology and Medicine. It was not until 1970 when the Society for Neuroscience was established that Neuroscience as its own stand-alone field was largely recognized.
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After the establishment of the Society for Neuroscience, Neuroscience gained validity in academia and many Universities founded programs for its study. The University of Michigan began to offer a graduate program in Neuroscience in 1971, however it was not until 2005 that this area of study was extended to undergraduates in the form of a Major.
Neuroscience has been an established field of research for less than 50 years, which means it is currently one of the most novel and fast growing areas of research. This is what is most fascinating to me about Neuroscience: the countless unknowns about brain function. Within the last 50 years, the most we have done is scratch the surface of how our minds work. While ancient mathematicians and astronomers focused their inquiries on the complexities that surrounded them, they neglected to investigate the complexities within them. The result of this was the delayed realization that there is more to our thoughts than initially suspected. So, after thousands of years, in 1971 our first formalized investigations into this field began, and when they did they had a very important question to answer: how can we scientifically define consciousness?
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When neuroscientists began to attempt to answer this question is when the common conception of consciousness began to split from a spiritual definition. In the terms of neuroscience, consciousness is defined as the state or quality of being aware of external objects as well as oneself. This definition of consciousness as synonymous with awareness has permeated more strongly into the common use of the word than its spiritual definition. As neuroscience has gained popularity and recognition, so too have its definitions for various concepts, consciousness being one of them. In neuroscience consciousness is a transient state of being. One that fluctuates on the day to day timescale as well as over one’s life. But neuroscience has by no means come any closer to holistically defining consciousness. It has merely defined it in a different, more nuanced way for the purpose of research. There are still so many questions about the origin of consciousness through the lens, one of the most pressing being: how do different interpretations of consciousness categorize levels of consciousness?