Consciousness 1: Plato’s Cave

The study of consciousness is an ancient one dating back thousands of years. For instance, in the Greek tradition, we have the idea of Plato’s Cave which posits limits on the ability of human understanding.

Suppose prisoners are chained from birth in a cave so that they cannot move or turn their heads. In front of them is a cave wall and behind them is a fire. Whatever passes between the fire and their backs casts a shadow on the wall. Puppeteers there hold up images and the prisoners see the shadows cast by the puppets.

Since the prisoners cannot turn around to see the actual object, they see the images and believe the images to be the only reality there is. They would be unable to distinguish between a horse and the puppet of a horse that cast the same shadow.

Plato then says (Grube/Reeve translation),

And if they could talk to one another, don’t you think they’d suppose that the names they used applied to the things they see passing before them?”


Plato’s Cave        

The terms in the language of the prisoners would refer to the shadows of the objects rather than the objects themselves. So if a prisoner referred to a shadow of a book, as “a book”, he would actually refer to the shadow of the book without any knowledge of the object that casted the shadow.

In fact, the idea of the object casting the shadow could possibly be beyond the comprehension of the prisoners.

The point of the exercise was that we are all a bit like the prisoners. The terms in our language are not the names of the physical objects we see. They are things that can only be grasped by the mind. These forms or ideas are thus the highest and most fundamental form of reality instead of the physical manifestation of these forms that we can perceive with our senses.

Plato goes further and likens the philosopher to a prisoner who escapes the cave and sees the world outside. But when he returns to the cave to tell his comrades about the wonderful world he has seen outside, he finds himself quite unable to communicate with them as they lack even the basic concepts to comprehend what he is telling them. In fact, they may turn against him deeming him to be a dangerous lunatic.

Thus in Plato’s view, philosophy could aid man by elevating his understanding and allow him to see the world as it truly is instead of relying on shadowy images commonly visible.

Plato’s idea is to my mind a powerful argument on the limit of the Turing test. There we measure a machine’s ability to mimic the effect of intelligence (its shadow) rather than to be intelligent.

The Eastern tradition also has a number of things to say on the subject of consciousness. According to many schools of thought, we are not only unable to see the world as it is, but are even unable to see ourselves as we truly are. Further, the traditions also recommend various practices to help elevate the consciousness of the individual so that these things become clear to him/her.

In recent decades that this study has moved from the realm of philosophy to science. With the development of advanced brain imaging techniques, it is possible to see the functioning of the brain in greater detail than ever before.

This has led in an explosion of research on the subject of consciousness, its states (e.g. waking, sleep, deep sleep, coma etc.), forms, measurement and development. Many interesting hypotheses have been generated (such as the Penrose Hameroff model) about the underlying physical structure that allows for consciousness to take place.

So what are the states of consciousness? Is human-like AI possible? What is the strong AI hypothesis and what it is to be a bat?

Over the next few weeks, I am going to look over some ideas and key research in the area of consciousness as I attempt to educate myself on this subject. Please stay tuned. Also, if any of you are active researchers in the field, please share, I’d love to learn about your work.




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