Do you know what it is like to be a bat?
I have been doing some reading on the tantalising question of what human consciousness is, and it has led me to some very strong arguments for the limitations of scientific explanations.
The natural enemy of the Christian faith today is no longer paganism as it was in the Apostolic age, but naturalism: the idea that nothing exists except that which is physical, made of matter and energy. The naturalist therefore only accepts that which you can examine scientifically and objectively. Anything outside this definition is considered not to exist or be real. Thus of course, the very idea of a supernatural God is unacceptable to the naturalist.
But human consciousness seems to pose an insoluble problem for the naturalist. In 1974 Serbian-American philosopher Thomas Nagel published a paper titled “What is it Like to be a Bat?” In it, he pointed out that no amount of objective, scientific knowledge can tell us what it feels like to be a bat. OK, maybe we can imagine flying like a bat, since we have our own similar experiences of flying in airplanes or floating under parachutes. But whereas we humans mostly experience the outside world through our sense of sight, bats mostly experience the outside world through a sense we do not possess: echolocation. They emit high pitched sound waves that bounce off their surroundings and they have specialised, highly sensitive sensors for picking up the reflected waves and creating a mental picture of the world around them. It’s a kind of natural sonar system.
Because we have nothing remotely like this sense of echolocation, we simply cannot accurately imagine what it is like to experience the world in this way – what it is like to be a bat. And this brings up the problem for naturalism. According to naturalism, since everything is physical, we should be able to understand everything. And yet here is something – what it is like to be a bat – that no amount of mere information or explanation can teach us. It seems to lie outside the realm of physical sciences; it cannot be reduced to mere objective facts.
“What’s the big deal?” I hear you asking. So we can’t pretend to be bats – so what? Well it turns out that this discovery applies to much more than bats. Especially, it applies to us. Physical, objective science seems to be totally incapable of accounting for what it is like to be a human being. There is something about the human experience that lies outside the whole realm of science. You might be able to map every single brain cell in your brain, describe how they work physically, how different bits are responsible for different jobs and even where exactly your memory of your dead pet dog Fido is stored. All this is physical, scientific explanation. But none of this will be able to explain why it feels like something to be you. That sense of being conscious, of knowing that you exist and experiencing all you experience cannot be explained by any amount of physical description and explanation.
Another way of looking at this is to point out the distinction between the subjective and the objective. The subjective is what you experience every day, the things you describe in the first person: “I feel cold”; “I see a tree”; “I want to eat”. You experience all these things in a way that no one else can, because you are the only one who is able to experience them from your own unique perspective. No one else can get inside your head and experience them exactly as you experience them. They may experience similar things in their own heads, but they can never experience them from inside your head.
“Hang on,” you ask, “don’t we all experience things the same way? We all see a green traffic light and know that we should go”. Well, can you be so sure about that? For example, how do you know that the colour you experience as green, the colour that produces a feeling of greenness in your mind, might not produce a feeling of redness in my mind? There is no way we could ever tell the difference. You have learned to go when you see a traffic light the produces greenness in your mind and you call it green. I have learned to go when I see a traffic light that produces redness in my mind, and I call it green. Our external behaviour is exactly the same, but our internal experience might be something quite different to each other. The subjective is directly available only to the person who experiences it directly and no one else, so it is impossible for us to know whether we really have the same experiences or not.
The objective on the other hand, is something that does not depend on any particular point of view at all – it is exactly the same for all observers. So, Nagel gives the example that if an alien race came to earth, even if they knew nothing about our language or science, they could still completely understand what a rainbow is. All they need are objective, observable, measurable facts and explanations of the physical world, which are the same everywhere and for everyone, even aliens. Note, however, that even with a perfect physical understanding of what a rainbow is, they will still be utterly incapable of knowing what it is like for a human being to see a rainbow, just as we are utterly incapable of knowing what it is like for them to experience a rainbow with whatever alien senses they may have. That first person, subjective experience is something they can never know purely from the physical facts.
So what does all this mean? Well it has some serious implications for the atheist who rejects belief in God on the basis that objective physical sciences are sufficient to explain everything there is. Remember that the naturalist says, “I don’t need God because everything in the universe can be explained using just the laws of nature without God.” Yet here is at least one thing that lies outside the ability of science to explain it. It seems to be something that is genuinely non-physical. You may call it whatever you wish: the mind, the psyche, the soul, the spirit, consciousness, sentience – but whatever you call it, it refuses to be accounted for by science. It seems to be hard evidence that there is indeed more in this world than things that are just made of matter and energy. And if there is at least one thing that is non-physical, then why shouldn’t there be more? The whole basis of naturalism is swept away, and with it, one of the chief arguments against the existence of God.
All from a bat! Who’d have thought so?