Is consciousness…Like software on a computer?
The third and final part in our quest to trace the history of the concept of consciousness.
This is part III and the last post in ‘ a brief history of the concept of consciousness’ series, which tries to look at how the very idea of ‘consciousness’ has grown and developed over time within the scientific milieu. These are the milestones that we’ve hit upon the previous two parts:
As we’ve gone through it all, we’ve discovered two rules of thumb to help point when the concept of consciousness experiences an upgrade:
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, Priestley’s idea that the mind is not a distinct substance from the body came from Newton’s work on the physical forces of nature; or 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.
The concept of consciousness experiences an upgrade 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.
A Busy Time (19th and 20th Century)
This final part of the history of consciousness will deal with how our concept of ‘consciousness’ evolved during the 19th and 20th century, all the way to the present. And perhaps the first thing to say about this period is that it has been busy, really busy. In fact, even summarizing the main events in consciousness research during this time would take a massive tome. (Luckily, other people have done the work for us, e.g. Blackmore & Troscianko’s Consciousness: An Introduction; or Schneider & Velmans Blackwell Companion to Consciousness). But the end-result of this busy period has been a mature, if enigmatic concept of consciousness. A good description of what the world presently understand by the term ‘consciousness’ was formulated by the philosopher John Searle in the year 2000. It is safe to say that this description is generally agreed upon in consciousness research today:
Consciousness consists of inner, qualitative, subjective states and processes of sentience or awareness. Consciousness, so defined, begins when we wake in the morning from a dreamless sleep — and continues until we fall asleep again, die, go into a coma or otherwise become “unconscious.” It includes all of the enormous variety of the awareness that we think of as characteristic of our waking life. It includes everything from feeling a pain, to perceiving objects visually, to states of anxiety and depression, to working out cross word puzzles, playing chess, trying to remember your aunt’s phone number, arguing about politics, or to just wishing you were somewhere else.
Contrast this definition of consciousness with that of William James a century earlier, who is widely regarded as the father of modern psychology — or rather, the lack of definition. Although James used the term ‘consciousness’ extensively in his work, he never really defined what consciousness was. It took the century-long work of many enlightened scholars to reach the definition formulated by John Searle.
During the 19th and 20th century, the concept of consciousness endured at least two fundamental metamorphoses that had to do with the two rules of thumb mentioned above: The one caused by the cell theory of life, and the one caused by the emergence of the computer, both of which we will be looking at in this post.
The Cell Theory (Late 19th century)
The cell theory of life is the fundamental notion taken for granted today that all living things are made up of cells and the products that they create. But this idea didn’t emerge out of thin air — it has its roots in the invention of the microscope in the 17th century with Antonie van Leeuwenhoek, which allowed scientists (or natural philosophers, as they were known back in the day) to peer at life with microscale resolution. But it took another 200 years after that for the cell theory to be fully developed, as additional tools that allowed scientists to look at both animal and plant tissue in more detail were invented, which were necessary to reach scientific consensus on the matter. And interestingly for our story, brain matter was the last one to be integrated into the cell theory.
The neuron doctrine is the idea that the nervous system is formed of discrete neurons, and is a cornerstone of modern neurobiology. But this theory only came to the fore at the end of the 19th century. Before, most neuroscientists believed in the so-called ‘reticular theory’ of the brain, which held that the cells of the nervous system are fused together and form one mass. Reticular theory held that nervous tissue is not formed of discrete cells like the rest of the bodily tissues are.
One of the most fervent proponents of the reticular theory was Camillo Golgi, who pioneered the cell staining techniques that first allowed individual nervous cells to be imaged under the microscope. Ramon y Cajal improved Golgi’s cell staining techniques, and it was he that around the 1890s produced definite proof that neurons were not ‘fused together’ as the reticular theory proposed, but rather were separated by tiny gaps, which we now call synapses. Golgi, however, remained unconvinced of the neuron doctrine. In 1906 , Golgi and Cajal shared the Nobel prize in Physiology or Medicine ‘in recognition of their work on the structure of the nervous system’, and even then, Golgi was still trying to convince the attendees to the award ceremony of the reticular theory. Nevertheless, by that time most scientists ascribed to the neuron doctrine due to overwhelming evidence in its favour, and so Golgi wasn’t very successful.
The main reason why it took so long for the scientific community to accept that the brain was made of individual cells is because brain tissue is very difficult to analyse at the microscale — it is soft, degrades very easily, and it has a more intricate structure than most other tissues that we know of, leaving room for a lot of speculation. It meant that understanding the nanoscale structure of the brain required advances in microscopy specific to the study of nervous tissue, and Golgi and Cajal were key in producing those advancements.
However, once it was established that nervous tissue was made of brain cells, the concept of consciousness changed fundamentally, since consciousness became something that arises from the activity of brain cells, rather than from ‘the brain’ as a single object. Numerous theories on how this might actually work came into existence, the most prominent of which is that neurons use a ‘neural code’ which transmits the information that forms our thoughts.
And here, we have a reflection of the first rule of thumb for when the concept of consciousness experiences an upgrade:
The concept of consciousness experiences an upgrade when our understanding of the body changes.
In this case, it was the understanding that nervous tissue is made up of cells, which resulted in the idea that consciousness arises from their activity, rather than from ‘the brain’ as a single object.
The Brain | Computer analogy (Early 20th Century)
Another big leap in how we approach consciousness came with the development of the computer during the mid 20th century. This spurred the prominent analogy of “the brain is like a computer, and the mind is like computer software”, that has been used extensively across the neurosciences and the philosophy of mind, and that many people find intuitive. This analogy has left a deep imprint on the cluster of field relating to consciousness studies. In the philosophy of mind, one of the most popular theories of consciousness is the computational theory of mind, which holds that the brain fundamentally does computations, similar to the computational processes of the computer; In the neurosciences, it has led to the idea that neurons are like the binary switches of silicon chips; In the field of artificial intelligence, it has led to the idea that consciousness is attainable for computers, since the human mind is just another piece of software; In the field of futurism, it has led to the prediction, endorsed by some, that an artificial super-consciousness is just around the corner, since it won’t be long before the computational power of computers will overrun the so-called computational power of all the human brains alive, becoming a super intelligence. In fact, the ‘hardware’ and ‘software’ analogies with the brain and mind have left such a mark, that in the popular literature they are commonplace enough to go unnoticed, so you may have found all of these examples all-too familiar.
But is the human brain|computer, human mind|software analogy valid? We will leave that question for another post. Suffice to say that this is a good example of the second rule of thumb we mentioned: The concept of consciousness experiences an upgrade when new analogies to the human body appear.
This particular brain|computer and human mind|software analogy of spurred a number of fundamental shifts in how we approach the brain and the consciousness that it gives rise to, and anyone interested in studying consciousness can feel the influence that it has had, since there is scarcely a popular article on the subject that doesn’t make use of the ‘brain like a computer’ metaphor.
The brain|computer analogy brings us all the way to the present, and concludes our brief foray into the history of the concept of consciousness. It is by no means a complete picture. We have left out some key developments, particularly those arising in the 20th century, including Thomas Nagel’s definition of consciousness as ‘what it is like to be’ something, John Searle’s Chinese Room Experiment, David Chalmer’s philosophical zombies, and more. ‘Is Consciousness…’ is dedicated to tackling these subjects, and as we do, we will update this post with links to each one.
But we had to start somewhere, and introducing the two main rules of thumb for when the concept of consciousness experiences an upgrade seemed like the right place to do so, since they were able to help us flesh out the most fundamental developments in consciousness research across the ages. Now that we have witnessed the power of these rules of thumb, one question looms: Are they powerful enough to be able to point us to the future development of the concept of consciousness? In the next series of posts, I would like to tackle this question, and address what I believe to be the future in our understanding of consciousness, based on the two rules of thumb described above.
