by Paul Singh
The evolutionary history of the brain’s development is already explaining many features about the ways we experience the world. However, it may be a mistake to ask why consciousness evolved. Consciousness has no existence of its own, and it couldn’t be an organ like a kidney. The brain processes that turn out to be responsible for conscious sentience and thoughtfulness are possible because the neurological structures of the brain that permit those processes did evolve over the course of mammalian (and especially primate) evolution. Being conscious needed no additional evolutionary work.
Consider an analogy with digestion. Mammals have the ability to digest many kinds of plant foods. Yet digestion didn’t evolve into existence, apart from the specialized organs such as the stomach and intestines which extract nutrients from food. Those extractions just are digestion; there is no mystery about how the extra feature of digestion had to evolve as well. Organisms are able to easily digest foods, and be conscious of surroundings, thanks to the evolution of the required biological features for those functions.
In a way, evolution isn’t responsible for evolving consciousness directly, since only the actual working functions of sentience would be immediately useful for survival. Avoiding a plant displaying a certain light frequency to animals with eyes because that wavelength signals a poisonous problem is a behavior that would be naturally selected for over many generations. Evolution eventually produces some species able to detect and avoid those plants. Whether an organism from one of those species subjectively sees those kinds of plants as reddish or yellowish, for example, isn’t selected for, since that extra qualitative color doesn’t make any difference.
Suppose two species both avoid that poisonous plant. For organisms of one species, its neural activation patterns allowing it to detect the poisonous plant might produce an experience of purple color while another organism might experience the orange color. Neither the purple nor the orange are caused by evolutionary pressures, not directly. Animals of different species don’t have to view the world the same way, so long as they can detect relevant features in some way or another. There is no evolutionary advantage to viewing the plant as one color or the other, so the qualitative look to the plant didn’t get directly produced by evolution. However, the underlying neural process did get produced by evolution, and the particular subjective qualities happened to be the result.
Here’s another analogy. All mammals have beating hearts, and all beating hearts make a heartbeat sound. We also know that all mammals evolved with their characteristic hearts. Did the heartbeat sound result from evolutionary selection? Not at all. There is no evolutionary advantage to the particular sound that a beating heart happens to make. That sound is simply the necessary consequence of having a beating heart, which was evolutionarily selected for.
Following that analogy, although it is true that being conscious is caused by our brains, it is that functioning, and not the accompanying qualitative feelings, which evolution is responsible for. Given the kinds of brains that mammals have evolved, conscious sentience of some sort or another was probably inevitable. But our actual specific kind of consciousness wasn’t our evolutionary destiny.25 We should not be surprised that animals with quite different nervous systems would have quite different kinds of consciousness.
Our species has had a unique evolutionary and cultural trajectory. The brain of Homo sapiens is capable not only of thinking, but also of thinking about thinking, thus permitting us to think about the thoughts and beliefs of others, and to invent communication systems like language so we can talk about thoughts as well as things. All this reflective thoughtfulness in turn yielded self-conscious reflection and recursive thinking, and a higher level of personal awareness than anything other species appears to possess.26
We depend on higher cognitive abilities, largely based in our large prefrontal cortex, to communicate our thoughts about having conscious awareness. You and I can pass communication tests about what we are sensing and whether we have conscious awareness, at least during our waking hours. Does an inability to pass a communication test imply that no conscious awareness is present? No, not at all. A newborn baby will fail every communication test due to an underdeveloped cortex, but conscious awareness is surely present. A “lower” animal can’t have much of a cortex at all, but that does not mean that no conscious awareness is present. We must avoid fallacious inferences that serve to undeservedly award to humanity an exalted standing over the rest of the animal kingdom. We stand out in our own awkward way, but not because we are the only ones feeling what it is like to be alive.
Our complex kind of conscious thoughtfulness surpasses all other species on that measure, as far as we can tell. However, using our human consciousness as the only standard for being conscious is like using a skyscraper building as the only standard for living in a home. Insects have homes, and they can be conscious, in ways peculiar to their species. It’s unfair to compare kinds of conscious awareness across very different species, since the structure of nervous systems can vary so widely across the animal kingdom. Asking whether a baby is more conscious than a bird would be like asking whether a crib is more comfortable than a nest. All animals enjoy the comforts of “home,” each in their own distinctive way.
Being conscious is necessary for enjoying life, but consciousness isn’t something that people have. Biologically and psychologically, it only makes sense to say that an animal can consciously enjoy eating food, but it is the eating of food that is enjoyed and not the consciousness as well. We don’t say, “That meal was a pleasure to eat, and my consciousness of eating was pleasurable too.” There is no such thing as consciousness as yet another thing for us to enjoy. We simply enjoy the things around us. It is the food that is enjoyable, not the consciousness of the food. Similarly, when I open my eyes and look at an apple on the table in front of me, I see the apple, not a consciousness of the apple. There aren’t two things, a seen apple and a consciousness of the apple, involved here. If I say, “The apple is in my consciousness,” I can only mean to say “I see the apple,” or “The apple is in my range of vision.” Imagine a psychologist asking a subject to look at that apple on the table, and then asking, “Don’t tell me whether you see the apple. I’m sure that you see the apple. I just want you to tell me if the apple is in your consciousness.” Surely this would be a joke. Seeing the apple is just being conscious of the apple. Having consciousness is simply being conscious of what’s going on. There is no such thing as consciousnesses over and above simply being alive and aware of one’s surroundings.
Inventing Consciousness
Some psychologists and philosophers (and many theologians) for various reasons, have inflated consciousness into something far more than just living consciously. Intricate arguments have been developed about consciousness and the mind to lend them their own content and substance, far beyond what happens when one is alive and attentive to the world. Every one of those arguments either amounts to talking about what being conscious is like (so adding consciousness isn’t really needed), or talking about imaginary properties that consciousness is supposed to have (but can’t be verified). The cognitive and brain sciences are already yielding scientific explanations for the brain’s ways of permitting organisms to live consciously. Science cannot be responsible for explaining imaginary properties.
Biology, psychology, and neuroscience naturally investigate how living organisms are capable of being conscious of matters around them. Those investigations are immensely challenging, without question. Fortunately, no additional inquiry into consciousness is needed as well, since there’s no such thing still remaining to be investigated or explained. Only when consciousness is assigned extra imaginary properties does the scientific challenge look impossible. Yet there’s no longer any challenge in the first place—only ignorant psychological or philosophical errors.
Naïve psychology can make it seem plausible to think that consciousness is an entity in itself that exists apart from the brain and can survive the death
of the body. However, detaching the mind from the body needs evidence. How about the evidence one can point to when there is some sort of awareness that appears to have nothing to do with anything bodily? Being aware of something, when there’s nothing actually there, might serve. We ordinarily refer to these kinds of experiences as illusions or delusions or hallucinations, or figments of the imagination. But any ordinary visual illusion will work. A visual illusion works for a person when their eyes are working normally and the cortical processing for vision is also working normally. The confusion arising when you look at a figure drawn on a piece of paper, like the “impossible trident” figure below, is quite normal—someone who is unable to see something odd about this figure must have an abnormal visual processing system.
Because the odd figure still seems so intuitively obvious—“It is right there in front of my eyes!”—a naïve person, ignorant of the brain’s neurological functioning, might ask, “Where is this odd figure, since it cannot really exist where it seems to be?” A two-dimensional figure is still there, of course—but we are speaking of the impossible trident—that three-dimensional figure that one’s vision also forces one to see as well. It is true that the impossible trident cannot be on the paper it is drawn on (or the computer screen it appears on). So where is that impossible trident, if it cannot be on the surface that it appears on?
One simple answer is that the impossible trident does not really exist, so there’s no “place” for it to be. But that answer doesn’t work. The question is not, “Where is the three-dimensional trident in the 3-D reality of space in front of me?” Everyone already knows that the impossible trident has no place there in space— that’s precisely the problem. Nor can the answer be, “There is no observed impossible trident.” Only a person suffering from abnormal visual functioning would say that. The rest of us observe the impossible trident, because we see the illusion. So the question remains, “Where is the observed illusory impossible trident?” This is not a stupid question. The illusion obviously has an objective reality to it, somewhere. It can be endlessly created and duplicated, and almost everyone sees it in the same way. Moreover, it can even be photographed, and every photograph shows the same illusion. We aren’t talking about a subjective fantasy or a hallucination. Almost everyone sees it regardless of whether they like to or not; and you can’t photograph a hallucination, but it is easy to photograph the impossible trident.27
At this point, naïve psychology can mutate into naïve philosophy. Taking the demand seriously to identify some sort of reality to the impossible trident, and unaware of neurology-informed psychology, a naive philosophy just makes up a second kind of reality to accommodate the impossible trident (and any other oddly “unnatural” things one may observe). In Western philosophy, it has been fashionable to call that second kind of reality the mental or spiritual or idealist reality, and consciousness is the unnatural stuff that such unreal things there are supposed to be made of. When we nowadays speak of visions or ideas in the imagination, that second reality gets invoked again.
A neurologically-informed philosophy, by contrast, wouldn’t have any need to make up a fictional metaphysics to explain illusions. The natural world around us, and the brain’s cognitive processes naturally within us, both contribute to what we can observe and how we observe it. The naïve psychological mistake is to suppose that observations should simply represent what exists out in front of our eyes, as if the brain made no contribution to perception. When naïve psychology is disappointed at the non-reality of the visual illusion in the outer natural world, it has no resources for explaining why, and it gets lost in puzzles.
As naïve philosophy comes to the rescue, its ignorance of brain neurology permits it to assume that when one kind of reality won’t do, a second kind of reality must serve. A neurologically-informed view of this matter instead explains that illusions are exactly what happen when a certain amount of information is presented to the eyes under conditions where the brain’s optical centers expect one thing but don’t quite get the expected sensory stimulations. The brain then generates a confusing observation, which is just as naturally real as any regular observation. The confusion felt when observing an impossible figure is proof that the observation is naturally generated and naturally real, because the brain centers processing that figure are themselves in tension over how to put that figure together from its components. If that impossible figure instead had an unnatural reality in some placid realm of consciousnesses, then the brain’s efforts and tensions wouldn’t matter. Everything in consciousness would be exactly as it is and as it should be, and nothing in consciousness should ever be confusing. But that’s obviously not how it feels to be aware and sentient.
Another example of an illusion affecting awareness that has been closely studied by the brain sciences is the phenomenon of the phantom limb. A person who has lost a limb from amputation can suffer from the strange illusion of feeling pain in the nonexistent limb. Rather than appealing to any naïve psychology struggling to locate where this phantom limb must be, the neurological study of the brain’s processes of stimuli has revealed how sensations are still generated by one part of the brain that used to deal with that (now missing) limb, and another part of the brain projects those stimuli onto one’s inner sense of where one’s body is located. These subsystems cannot be simply “told” that the limb is actually gone. However, they can be fooled and re-trained by clever therapeutic experiments so that the disturbing symptoms are reduced or eliminated.28
A perennial favorite among mystics, spiritualists, and idealistic philosophers is the phenomenon of the out-of-body experience. This phenomenon is internally generated by a person’s own neurological malfunctioning, so it is hallucinatory rather than illusory, and the brain sciences are beginning to explain it. The crucial factor is that the brain’s ability to maintain an inner awareness of what is going on inside the body is different from its ability to monitor where that inner bodily awareness is located with respect to the external world the body interacts with. Unless those two separate abilities are further coordinated with each other, an inner feeling could not be located in external space. For example, without that additional coordination, a toe pain that can be felt while one’s eyes are closed would not feel like it is located in the toe you can see with your eyes. Now, imagine what would happen if that coordination were severely disturbed, or disconnected, by brain malfunctions. One’s inner sense of one’s body would be detached from where the brain thinks the body is located in the world. Other parts of the cortex responsible for weaving together a coherent narrative of events would try to resolve this bizarre discord with all sorts of odd experiences: the sensation that one is floating above one’s body, the belief that one’s soul has departed the body and can travel around, and so on. Although the neurosciences have much work remaining to fully account for all the different kinds of dislocative hallucinations, there is no need to resort to immaterial souls anymore. What is surely discredited by now is the naïve psychological presumption that convincing experiences must be accurate. Most experiences, especially the most certain and intuitive, are distortions and exaggerations at best, and they are more about what the brain is compelled to think than what reality is likely to be. Hallucinations are just hallucinations, after all. Just as children need to be eventually told that even the most realistic dreams aren’t really journeys into a different world from ours, adults still need to be told that the most realistic hallucinations are the ones least to be trusted.29
Scientists aren’t immune from convincing hallucinations. Eben Alexander’s tale about visiting heaven while in a coma says far more about his naïve psychology than his scientific expertise. His case is regrettable because of its deeply naïve childishness, both psychologically and religiously. His “proof” rests on his naïve belief that just because it subjectively seems to him that his vision happened while in a coma, therefore it must have really happened during that time period. His naïve religious conviction that his vision of
heaven must be a completely accurate portrayal is betrayed by the way that his “stunning” revelation turns out to be a reassuringly benign depiction favored by the bland liberal Christianity lately preferred in America. Unwilling to admit how his slow recovery from a coma through stages of re-awakening unconsciousness and then an impaired consciousness gave his own brain plenty of time to confabulate his hallucinations, he insists that his spiritual travels must only have happened while he was in his coma, although he has absolutely no evidence, subjective or objective, for that claim whatsoever.30
Naïve psychological intuitions and stubborn religious convictions can sustain belief in immaterial spirits and immortal souls for as long as there are ignorant and unscientific people in the world. Even more regrettable, philosophy has supported those naïve beliefs with what appear to be logical arguments. Unscientific philosophy has been able to talk about “consciousness” ever since the word was invented during the Middle Ages. For centuries, this consciousness (mind or soul) has been credited with possessing all sorts of unnatural and immaterial features and powers. Philosophical discussions of consciousness down to this day have a common strategy: start from the claim that this consciousness has key features that aren’t simply examples of being aware or sentient or thoughtful about what is going on, and then claim that only a second kind of mental reality can explain those peculiar features. Philosophers make this claim appear intuitive and hard to deny. It’s so easy to convert being “conscious” into “consciousness” just by adding the suffix “ness” to that word. The English language makes it easy to convert an adjective into a noun. What else can the suffix “ness” get attached to, in order make a new thing seem to pop into its own existence? If that apple looks red, then why can’t that apple have redness. Then why can’t we just detach that redness and suppose that redness can be its own sort of entity, quite apart from red things like apples? After this linguistic magic, philosophers can then say things like, “I see the red apple in front of me, but I can also be conscious of that redness as well, and that redness is something else besides any apple’s color.” And where is this extra redness, if it isn’t something in the apple itself?