Time to refurbish Plato’s cave…
Ever since I read republic, the questions that bothered me most were…
What really lies behind Plato’s cave ? What does it really tell us about human consciousness and its interpretation of nature of reality ? What should be the prudent way to approach it in light of modern day neuroscience?
In Plato’s cave a group of people are depicted as living in a cave since birth, they have never seen the light of day. These people are chained so that they can’t look to sides or behind them, their gaze is fixed on the wall ahead. Some way up behind them a fire is burning and between the fire and people, there is a road, and in front of road stands a curtain wall like that in puppet shows.
There are men carrying all sort of figures along behind the curtain wall, projecting above it the figures of men, women and animals made of wood, stone and all sort of materials. The prisoners hear the noises but can only see the shadows of the objects projected on to the wall in front of them. The prisoners watch the stories as the shadows play out on the wall, and they believe the shadows to be the most real things in the world.
Now if one of the prisoner is dragged out of the cave to the real world. At first, his eyes will be dazzled by the light as he can only look at shadows, but then he would realise that there are things out there that are more real than the reflections of reality that he has been exposed to all along.
This would be the first glimpse of reality for him, first he would have an urge to rush back to the cave and look at the shadows as he is accustomed to do so but if he stayed out for some time, even against his will, he may be able to comprehend this new found reality.
Plato argues that escapee at that point would have reached the state of mind where he has caught his first glimpse of the more real things. He may go back and try to teach others about his new found reality, but they would see it as madness and will try to kill him.
The cave represents the state of most human beings trapped in their conscious selves, the forms are the essences of various objects, or the nuts and bolts, the building blocks of the conscious experience and exit from the cave represents the enlightenment and attempt to look at real nature of things.
Plato’s forms are abstract non-material substances, a kind of super-ordinate to matter, most pure of all things. Plato believed that true forms are beyond the reach of humans, and we can never see forms even though he holds the notion that there are some who can see beyond what others are not able to.
So what really are these non material substances, is Plato really talking about our cognitive categories or something else that that is beyond our cognition.
Modern neuroscience suggests that our conscious self is not the complete picture, it is just tip of iceberg, the real game player is the subconscious self. After all it is subconscious self that deals with raw data that is projected by the environment on to our senses as we interact with elements of our environment.
Let’s take the example of our eyes, the retinas in our eyes have in excess of 100 million photosensitive rod and cone cells. It is the reflected light in form of photons that advertises the shapes, textures, boundaries of objects to our eyes in forms of reflective wavelength. The signals are eventually carried to the visual cortex by about a million retinal ganglion cells that form part of the optic nerve.
Here is the problem, somehow 100 million possible excitations had to be pushed through a pipe that can only carry about a million signals at a time. So the signals have to be chunked up, some information need to be dropped, this is where the categorisation begins.
When we are taking multiple inputs and compressing them into one output we are categorising.
Lateral inhibition plays a key role to help us categorize things in our visual field. Lateral inhibition works by inhibiting the signaling of surrounding neural connections. It helps in contrast enhancement and establishment of clear boundaries for categories.
Categorisation is an inescapable consequence of our biology, it is not just the biologist that neatly carve life forms into species, genus, family, order, class, phylum, kingdom, domain, our everyday perception does not work without categorisation at all. We need categories to perceive things, categories to reason about perceptions and categories to act on those perceptions. This is not to develop a deep understanding about them but to make everyday decisions that our biology demands from us in order to survive and to thrive in our respective environments.
One key feature of this categorisation is that it is largely shaped by not only our neural circuitry but the bodies that this neural circuitry is housed in. Our categories make sense to us because we have evolved with them, our category of a tree, a banana, a flower, a boy, a girl are only relevant to us.
An insect does not see the flower in the same way as we do because the insect has its own way to categorise it.
Following examples illustrate an insect’s and human’s eye view of a flower.
Here is another example of how a wasp categorises an orchid flower as a potential mate.
Image: http://www.visualnews.com/2013/04/08/hidden-patterns-how-a-bee-sees-the-world-of-flowers/
There is no shortage of examples to illustrate the fact that all life forms do characterise things in their surrounds as they seem fit, I have also covered in a previous article about frog’ eye and how it characterizes all moving things as its prey.
Well if categorisation is so ubiquitous, single celled creatures like bacteria or even creatures without a cell like virus must have a way to categorise as well. It is another matter that we may call it rather rudimentary but whatever it is, it is its cognitive ability.
Did I say bacteria have cognitive ability ? Well ! now I am in real trouble.
How do we get i of this labyrinth?
If we say it is only humans who categorize, that is not true, we know all life forms have to categorise at least the basics i.e. prey, predator and mate. If we say to categorisation is not cognitive that does not serve the purpose either, and if we say that all life forms that characterise have a mind, that does not make much sense either.
So may be we have to revisit our definitions of what does it mean to be cognitive, either we accept that categorisation is not a mental process, otherwise we have to re-evaluate our definition of mind.
If we accept the notion that ability to categorise stuff is ubiquitous and for it to be so pervasive it has to be embedded in very fabric of life. In order for it to work at such a scale it has to operate in every process, every cell, every organ and every body, so instead of some divine manifestation as suggested by Plato, the forms must have a some underlying molecular basis.
If that being the case it is time to refurbish plato’s cave, time to replace the stones and bricks with some molecules of categorisation.
Originally published at scriptgrandeur.wordpress.com on July 25, 2015.
