Steve-65, CC BY-SA 3.0, via Wikimedia Commons
Look around you, you see things in the world — close your eyes, the things vanish. Open your eyes, the things return; place hands over your eyes, the things vanish again. Place one hand over your eyes, and only half of the things remain present.
You see a table; touch it and now you can also feel it as hard, coarse thing. Touch a glass and it feels hard, but smooth. Place a finger in the water in the glass: you sense something cool and wet.
When a dog has his eyes open, move something around in his presence and he will follow it. If his eyes are closed, he won’t — unless you make a loud noise, or have a strong scent, and then his ears may prick, or his nose may twitch, and he may react accordingly.
On hard surfaces the dog walks tentatively, careful to avoid the pain of sharp impacts between his soft paws and the ground. On soft earth he runs earnestly and eagerly, and in water he splashes playfully and relentlessly.
Can you prove whether the dog really has sensory experiences, or is he simply a very sophisticated automaton? We know that he cannot differentiate red and green leaves, but he sees something when he sees the leaves, right? He also differentiates scents that are undetectable to our feeble human noses — could his seeming experience of scents also be an illusion? We can in fact discern many things about the structure of his “experience” — but the exact nature, and even the existence, of his experience, his internal universe, can never be known to us directly. There is a gulf between his experience and yours — an unbridgeable gulf, as wide as that between mine and yours, or between any two conscious entities. His universe is not yours and yours is not mine; and yet we can communicate.
Did the horse Nietzsche embraced in Turin feel pain, or was Descartes correct when he asserting that lower beasts are pure body, with no consciousness or awareness? With further investigations we have discovered that dogs, horses and humans all possess complex nervous systems, woven into intricate structures of elaborate hierarchical patterns, with nerve cells pulsing and self-organising into a sophisticated orchestration of feedback loops and nested control systems.
All of these nervous systems develop according to schematics laid down in the animal’s genetic code, and all serve to coordinate motions of muscles and limbs in line with synthesised messages from sensory organs; and all of this bafflingly complex array of activity is unified smoothly into the twisted leap of a dog catching a stick, the swerving gallop of a horse, or the tightly controlled fling of a human hand and forearm hurling a spear. Other animals possess their own apparatus to interact with the world: ants and beetles, with eyes, muscles, and more rudimentary brains, move in tightly-scripted patterns; jellyfish, with nerve nets but no brain, quiver in response to stimuli; even bacteria, with only one cell, modulate their motions according to chemical gradients in their vicinity.
Bodies are complicated, sophisticated and continuously active; strange and alien landscapes of activity lurk beneath the skin of any creature you see, and beneath your skin. The “amphibious entity” that is the nervous system conceals layers of hidden mysteries in its ever-shifting tapestry of patterns and meta-patterns; the tricky notion of information, and its peculiar relationship to messaging, signalling, and interaction, is intimately intertwined with these mysteries.
It is difficult to maintain the doctrine of a clean separation between bodies and consciousness, between matter and awareness, between experiencer and experience, when the facts above are perceived clearly.