This post links together two ideas - Plato’s cave and the generative brain hypothesis. The ideas for this post originate from Plato’s The Republic and Surfing Uncertainty by Andy Clark.
Plato’s cave is presented by Plato in Book VII of The Republic.
The dwellers in Plato’s cave have lived their lives chained to a wall. Their entire world is only the shadows they see on the walls - never seeing the objects and fire responsible for their shadowy world.
For Plato his objects are Forms - the true, underlying, absolute things that are more real than any object that imitates them.
The philosopher is one who escapes the cave and can see the true Forms - but he will find cave dwellers are reluctant to leave their version of reality to see the truth.
The key takeaway for us is the difference between the real world (the object) and our experience of it (shadows on the wall).
The idea in this section comes from the excellent Surfing Uncertainty by Andy Clark.
The hypothesis is that the brain is a generative, probabilistic model that predicts the world. Our brain constantly generates predictions of the world. Our experience is only this prediction, not of actual reality.
Naively we think of our experience (what we see, feel and think) as directly linked to stimulus from our environment. In fact, our experience is not environmental stimulus, but of our prediction of it.
Our predictions are our conscious experience. We never experience actual signals from the environment - instead we predict these signals, and only experience our prediction.
The world is a simulation - generated inside your own head.
We see the world by guessing the world, using our senses not to take action, but to make better predictions. Our actions are made from our predictions alone.
Let’s now bring these ideas together:
Plato’s cave exists - it is your experience of the predictions your brain generates.
What experience is our cave - shadows and impressions of whatever the truth of the world is, predicted on the walls of our skull.
Thanks for reading!