My friend Ned asked me to comment on a line from my book, and I thought it deserved a thorough answer. It’s one of my favorite topics and I hope you’ll find it interesting as well. It has to do with how our biology affects our philosophy and our identity.
The passage is from the very last page of “Life in Space: Astrobiology for Everyone.”
“Finally, our biochemistry impacts our identity, science, and our beliefs. It may
not determine them, but it does have an impact. Our intelligence appears to
have novel properties unique to such a complex level of organization. We
must be ever vigilant to how our biology affects our morality.”
First, let me defend the the premise that our biochemistry impacts our philosophy. From the time of Descartes, we have tended to think that mind and body are separate things, so it can be a bit challenging to think about our physical selves shaping our mental selves, but science has been quite convincing in this regard.
At the most basic level we know that our perceptions are physically conditioned. We see things when light hits our eyes, but only the some light. It has to come in the right wavelengths to change the conformation of a protein . For humans this is roughly 400-650 nm light, ranging from violet to red. Visible light, it turns out, is not a property of the universe, it is rather that set of photons that interact well with human eyes. It’s not really as human centered as that. Photosynthesis, as bacteria and plants use light to make chemical energy, also runs between 580 and 1060 nm. It turns out that that kind of light is good for doing chemical work. Nonetheless, our ideas of light and color have been heavily influenced by our biochemistry. Red is not a real thing. Red is a concept we’ve invented to describe the kind of light that stimulates our long-wavelength (564nm) cone protein. Different species, with different light receptors, would have different concepts of color.
We cannot help but perceive the world through our senses. Each sense differentiates and observes the world on the basis of contingent categories (3 types of cones in our eyes to differentiate color, 5 taste receptors on our tongue to differentiate taste, and so on). Science, being based on our senses, has this kind of graininess to it. We begin to perceive things beyond our senses once we start looking for them – we now know of other wavelengths of light. Still, it’s impossible to know what questions have not been asked yet. So our biochemistry limits the kinds of categories we have to work with.
This graininess impacts how we look at ourselves and how we conceive of the universe. In the book, I talk about how we define intelligence as “human-like in reasoning.” and life as roughly “human-like in reproduction.” We’re working from known examples…and those known examples have been labeled by our biased senses.
I’m not saying it’s hopeless. Far from it. I am saying that science is beginning to show us just how deeply biased we are by our context. As we learn more about the context, we can attempt to account for, measure, and transcend the it, knowing always that we may be unaware of the most important biases to transcend. Astrobiology, in identifying our context, provides great philosophical returns as it shows us how we are constrained by environment and evolution. This is one of the weaker versions of the Anthropic Principle – as humans we cannot be surprised to observe a universe in which humans exist, in fact it is a tautology. We could not observe the universe if we did not exist.
On to the question of morality. If our biochemistry shapes the categories by which we reason, it also shapes the categories by which we do moral reasoning. It seems clear to me that most faiths privilege human beings. Our greatest responsibilities are to humans. After that, we have responsibilities to all sentient beings and to all living things. These categories (terribly useful categories) have been shaped by our biochemistry. The scientific category “Homo sapiens” is often used synonymously with humans and people. I think this limits our theology in important ways – ways that the search for extra-terrestrial life illuminate. Could we ever consider another species intelligent? Or will we always redefine it so that it includes us alone? Will we always consider humans to be our primary “neighbors” in Christianity? Or could Christ have meant us to extend that further?
Some of the greatest moral failures have been failures of imagination. Literalists in science and religion are increasingly calling for us to limit our thoughts to strict definitions (of human, God, moral). They ask us to force our scientific understanding into a particular theological box – or force our theological understanding into a theological box – and yet science continually tells us just how dangerous those boxes can be, even when we find them most useful.
My point in the book and my point here is to challenge people to be more self conscious about the way they perceive the world – and the ideas they use. Both have been shaped by their physical context. (Perhaps their mental one as well, but that’s another blog.) A well informed theologian, a well informed scientist, even a well informed general consumer of knowledge has the tools to be self-critical about how they think about the universe. They are not separate from it, but deeply entrenched.