11 A Vision of the Future

If, as seems evident, the main business of the nervous system is to allow the organism to move so as to facilitate feeding, avoid predators, and in general survive long enough to reproduce, then an important job of cognition is to make predictions that guide decisions. The better the predictive capacities, the better, other things being equal, the organism’s chance for survival.

—Patricia Churchland (2002, p. 40)

An early riser, I found our camp swathed in cloud when I got up. While my brother slept in the tent perched on the high mountain ridge, I started a fire in the tiny stone stove we had made and fed it chips of wood as the water in the pot above began to simmer. Cliffs fell away for thousands of feet on two sides of the camp, although I could see only a few feet through the fog in the dim dawn light. The stove, which was only slightly larger than the pot sitting on it, was built against a rock face that angled downward alongside a ridge broad enough to stand on. A number of hand-sized pockets had somehow been scooped out of the cliff face by ancient geological processes, and putting my face up to one of these, I discovered a microcosm inside. In a cup of soil there were dwarf grasses, miniature cinquefoil, tiny succulents, and mosses growing in their stone shelter. As the moist cloud collided with the cliff face, tiny beads of water condensed and ran down into the tiny world in the rock, supplying it with life-giving moisture. I fancied myself living in that diminutive world, looking out of the opening into the mysterious world outside.

Some ravens came up over the ridge riding the up-drafting breeze, croaking back and forth as they checked out the campsite, shaking me out of my reverie. I searched the mists to see them, but they floated on over the other side, never coming close enough to be seen. Those ravens, my brother, the mountain ridge, and I were also in our own microcosm, our own smaller world carved out of the larger universe around us. Our mountain ridge and all of the mountains and valleys for 50 miles in any direction were inside a large national park that had been protected from human incursion for over a century. Instead of a pocket in the rock, we were protected inside a pocket carved out of the economic landscape of humankind. For countless millennia our ancestors sheltered in caves against the wilderness. Now the wilderness found shelter against humankind in parks like this. Things evolve continuously, the tables turn continuously. Yesterday’s competition becomes today’s symbiosis; yesterday’s invader becomes an essential part of today’s body.1

From my unique human perspective the whole commanded admiration—and it got it. A golden glow suffused the fog as the Sun began to penetrate the mists. The awesome vertical slabs of stone above us gradually emerged against the painfully blue sky, and then the beautiful, green, tree-lined valleys were unveiled below.


The wilderness used to be the place where human beings were threatened with danger and death. It is now the place where we are the threat of danger and death. This represents a role reversal of magnificent proportions, a historical fact that we will be digesting for generations. In our urban and urbane romanticism of nature, we forget that nature is not our friend. It is totally indifferent to us. Nature is the arena in which we, along with other living things, have struggled to survive. Far from being a system, the natural world is a battle. Despite all of the poetic talk of ecosystems, or of the ecosystem, no system is made of such strife. Organisms, like all systems, are built of cooperation. And no organism can survive without carving out a space for itself and competing for access to the necessities of life with its own kind as well as with other kinds. True enough, in the end we all unwittingly play into the hands of the other competitors in the evolutionary contest, and to that extent there is a system. What the plants breathe out we animals breathe in, and vice versa, for example. But that does not stop us animals from eating plants. Indeed, ultimately all animal food comes from plants. Poor plants, they cannot even run away when lightning sets fire to the forest or the prairie. The body of a plant or an animal is a system precisely because it does not involve these sorts of internal battles. No part of your body eats another part, or infects it, or burns it up in a fire. To think of the ongoing drama within the cauldron of evolution as a system requires selective blindness, romanticization rather than real romance.

There is now a chance that nature may become a system, but only if we realize the role reversal that is taking place. It is not taking place for all of humankind at the same rate. Many people still do not have the upper hand over nature in the struggle for survival. From their point of view, nature does not have the romantic glow that it has developed for the city folk in the developed world who have gotten a bit of an upper hand over nature. The subsistence farmer who carves a cornfield out of the forest will not have the same sympathy for sparing the wilderness from human development as the city dweller will have. It is only because some of us have become secure in the struggle for existence that our sympathies can now extend to our erstwhile competitors. The role reversal of getting the upper hand over nature is necessary if nature is to be spared the depredations of human beings. In the end, human destiny cannot be divorced from the destiny of living things in general. But that can only be appreciated by those who are not facing death, suffering, or constant work just to survive. Nature will do best if we do best. National parks are promoted and protected by the prosperous.


I am arguing that we should step forward to accept our responsibilities as nervous system of the planet instead of stepping back to let Earth continue colliding blindly with whatever fate happens to send its way. Whether or not you believe in a higher order, you cannot believe that we bear no responsibility for Earth’s fate. My argument has two fundamental premises. The first is that we are in fact emerging as the sensory and motor system for the planet, whether we like it or not, and the second is that if we willingly engage in this process with our eyes open it will be better both for us and for the planet as a whole than it would be if we do not. By a nervous system I mean an information processing system with the three main functions of a nervous system. First it collects information about the state of the Earth (proprioception) and what the planet is likely to encounter in its trajectory through space. Second, it stores and processes information in order to learn how Earth’s organisms and supporting systems work, the needs of those organisms and systems, their main threats, and how those needs may be met and those threats may be avoided. Third, it directs those behaviors it controls for the good of the whole. We can perform the same information processes for the Earth that the nervous system performs for an organism. In this sense the analogy between us and a nervous system is very close.

There are big disanalogies as well. For one thing, humans are not neurons, but entire animals. Each of us has our own mind, consciousness, intelligence, and ideas about what would be best for the environment. Neurons have no minds, no consciousness, no ideas about anything. Neurons are not smart cells, but electrically hyperactive cells. Neurons are just the sort of cells that might be used to construct an information processing system, as the process of natural selection has discovered, but they are just as unintelligent and unconscious as the cells of your liver or bones. Within the limits of their normal operating conditions, neurons behave more or less mechanically, firing when sufficiently stimulated by incoming signals, resting otherwise. The mindless consistency of the neuron is a good thing as far the nervous system is concerned, because information processing requires consistency. Human beings, by contrast, have minds of their own. They do not mindlessly fire when sufficiently stimulated. Instead, they receive information by seeing something or being told something. They may or may not pass on the information received, and if they do pass it on, they transform it in the process. If you see a dog you normally see an indefinite number of things in the process, such as the size and color of the dog, the location where you saw the dog, when, and what it was doing. You may or may not tell someone else about it, and if you do choose to pass on any information you must choose what to report of all the many things you perceived.

Nevertheless, despite this disanalogy, groups of human beings do collect, process, and use information. Indeed, we are adepts when it comes to information, unique among the species of the Earth. Human beings as a group are aware of everything from dinosaurs to the threat of global warming. As a group, humankind could perform the three planetary information functions outlined above: seeing, thinking, and acting. We could transform the planet by providing it with intelligence. And this brings us to another big disanalogy between us and nervous systems: we could provide the planet with senses and intelligence, but we have not done so yet. So far our most intelligent actions from the point of view of the planet as a whole have been to address the problems caused by our own waste products, our pollution, by reining in that pollution. These are humble beginnings, indeed, but they are beginnings nevertheless. We have shown that we are capable of seeing, thinking, and acting on behalf of all life on this planet. Indeed, we have shown this by acting as a simple and flawed nervous system. Now that the threat of global warming has been communicated to the global public, whether humankind chooses to act or not to act, it will as a matter of fact bear responsibility for the result. Thus we are emerging as the nervous system of the globe, although we are so far a feeble force for well-informed intelligence. If we can but see, collectively, what we are becoming, we can make the transition more efficiently and more advantageously for ourselves as well as for all the other living things on Earth.

So one argument is that we are emerging as the information and control system, or “nervous system,” of the planet anyway, like it or not, so we would do best for all concerned if we squared up to this fact. Another argument is that environmentalists in general presuppose that we play the role of planetary information and control system, for they propose actions for the good of the planet on the basis of their analysis of the facts as they see them. Every proposal for action by every environmentalist group, including the Kyoto protocols, assumes that intelligent, well-informed action on behalf of the planet as a whole is possible. The main argument, however, is that it would be good both for us and for the rest of nature. In principle this is an argument that is accepted by environmentalists, but only in part since doing what is best for humankind is not their concern, and furthermore, they may disagree among themselves or with others about just what would be best for nature. Generally speaking, environmentalists think that the best thing we could do for the environment is to leave it alone. They picture us as having caused the “environmental crisis” in the first place by poking our fingers into natural mechanisms, and they recommend that we now take a strict laissez-faire approach. If only human beings had never existed, whatever state nature might be in would be not only good, but ideal. As environmentalists see it, we are the one and only environmental problem, and the solution to the problem is for us to remove ourselves from the scene and let nature once again follow its own course.

That is the way back, the return route to our primordial relationship with nature, whereas I am recommending a route forward in which we carefully, respectfully, take responsibility by influencing the course of events for the good of nature. People have differing ideas about what is good for nature, and widely differing ideas about what is good for humankind. Nevertheless, there is a fundamental, foundational level of good, which I have called natural good, that will enjoy much broader support. It is naturally good to satisfy the natural necessities (the need for nourishment, sunlight, water, shelter, etc.) of organisms. What makes nervous systems naturally good and favored by natural selection is their ability to provide the necessities of life for the organisms that have them. Similarly, as nervous system of the Earth, we would have the task of tending to the necessities of the totality of living things on Earth. No matter how much people might disagree about what is good for the environment, they can all agree that satisfying natural needs of the organisms living in the environment is a good thing. Indeed, unless these needs are met, we too will perish. Attending to these needs will be a good recognized by all environmentalists, with the exception of the needs of one species, our own. For environmentalists, Homo sapiens is a criminal species, the source of all environmental harm, and satisfying its needs is not necessarily a good thing. Indeed, satisfying the needs and desires of humankind is the original sin, the source of all environmental woes, so satisfying human needs is automatically assumed to be wrong, at least until it can be shown to be otherwise.

Fortunately, it can be shown to be otherwise. Moreover, one of the reasons that it is otherwise is already implicitly recognized by environmentalists: Human beings have a special nature, unique among the species of Earth, which enables them to appreciate the environmental state of health of the planet and to act on its behalf. Environmentalists implicitly recognize this in two ways: First, they themselves are human beings who appreciate the state of health of the environment and act on its behalf; and second, in seeking support for their cause among their fellow human beings they presuppose that other human beings have this potential as well. Environmentalists are apt to overlook the fact that only human beings have this potential. In their blind faith in the goodness of nature, they overlook the fact that other species are totally incapable of recognizing environmental facts and values, or acting on them. All other species are driven solely by instincts and desires that give their own species an advantage over other species in the continuous struggle for survival and reproduction. In this regard they are like human beings prior to their environmental awakening. There are no environmentalists among any other species other than our own. Every single environmentalist is a human being, and there is a crucial lesson in that fact. Whether or not it is part of some grand plan or merely an accident, human beings have a unique nature that enables them to be sensible of the value of nature. This sensibility gives them a special responsibility, a special role to play. Their needs and necessities therefore cannot be overlooked by environmentalists, despite environmentalists’ tendency toward an antihuman bias.

The second reason is that the environmentalist’s blind faith in the goodness of natural processes is misguided. Natural processes have repeatedly brought life on Earth to the brink of extinction, and they may do so again. Imagine that we knew a comet was going to collide with the Earth, causing terrific destruction, much like the destruction that was caused 65 million years ago when such a collision brought the age of the dinosaurs to an end. Suppose that we had the power to stop the collision. What would be the environmentally responsible thing to do in such a case? On the one hand, the environmentalist has faith in the goodness of nature and natural processes as long as they are not influenced by humankind. On the other hand, the massive extinction of species that would be caused by such a collision (at least 90% of all species would be exterminated) can only be seen as a bad thing, something that is to be avoided at all costs. The environmentalist cannot consistently condemn every species extinction caused by human beings while tolerating or praising those that would be caused by a comet smashing into Earth. Only sheer self-loathing at the species level could explain such an attitude, and nothing from an environmental point of view could justify it.

If we may assume that most environmentalists, if given the choice, would choose to avert this natural environmental disaster, we may conclude that their antihuman bias does not run as deep as their concern for the good of living things in general. When push really comes to shove, they are capable of appreciating the special role that human beings, and only human beings, can play in the protection of the environment. In principle, at least, environmentalists cannot help but admit that human interests are not implacably opposed to environmental interests. Regardless of whether environmentalists do recognize these things, the fourth argument for human beings serving as the nervous system of the planet is that doing so would recognize crucial facts: in particular, the fact that we are completely alone among all the species on Earth in our capacity to recognize environmental realities and values, and work on behalf of all living things.


Nervous systems have arisen via the process of natural selection because they provide the animals that have them with advantages in the evolutionary struggle. These advantages may be placed under two headings: integration and intelligence. Integration includes all of the information functions required to make a single animal out of the millions or billions of differing cells from which it is composed. Intelligence includes all of the perception and thought involved in directing the actions of the animal so that they work for the benefit of the animal as a whole. Both of these functions require solving nontrivial problems of the general form of harmonizing drives or goals that are in tension. For example, it is essential that an animal not eat or attack its own parts, although sometimes the welfare of the whole will require that the welfare of a part be sacrificed. An integrated animal will recognize its own body as something it cannot eat no matter how hungry it is and no matter how nutritious its body might be. Although not eating or otherwise harming one’s own body seems a perfectly obvious policy, it is not perfectly obvious just how a nervous system can ensure this form of integration. Fortunately, evolution has developed a number of workable solutions to this problem, although occasionally even human beings can get carried away chewing their nails, scratching themselves until they bleed, and so on. In tension with the need to protect the body, intelligence might require that one run through thorny bushes that damage one’s body in order that a predator might be escaped, or that one burn one’s hands opening a door to escape a fire. Again, nervous systems have evolved that have workable although not ideal solutions to these problems as well.

So the primary benefits we can provide the living things of the Earth are integration and intelligence. What this entails in the fullest sense would take us far beyond the scope of this book. In this full sense, only an ongoing investigation and discussion as events unfold can address the problem. However, if we restrict ourselves to natural goods, in particular survival and the necessities of survival, a number of crucially important basic goals of a planetary nervous system can be established. For example, the physical and chemical variables of the planet must be maintained within certain bounds. Extant species may be assumed to have the right to survive, unless they threaten the survival of other species or of the whole system. Just as an animal may rid itself of a harmful infection or parasite, so too the whole system of nature may rid itself of harmful infections or parasites. There is no assumption that everything within nature is sacrosanct. The good of the whole is primary, not the good of every single part without exception.

The human species is no exception to this rule. We too are not sacrosanct. Our right to exist depends on our being good for the system as a whole. Fortunately, nervous systems are generally so beneficial that they are accorded levels of support and protection within the animal that other components of the animal do not enjoy. When the animal is threatened by shortages of warmth, food, oxygen, and so on, supplies of these necessities are restricted for other parts of the body before they are restricted for the nervous system. If an animal is suffocating, the last part of the body to suffer loss of oxygen will be the central nervous system, the brain. Humankind stands to gain this special status within the Earth system if it accepts the function of information processing on behalf of the whole system. Our rights to special consideration within the system are only potential, not actual, at this point. We are emerging as the nervous system of Earth, but we have not achieved this status yet. This is yet another argument for taking on this task: It would justify our existence from the point of view of environmental values. In the next section we return to the special status we would have in an integrated system of nature.

One way to get a grip on what it would mean to perform the functions of integrating the natural systems of the planet and providing them intelligence is to see how nervous systems sometimes fail. We can get a better idea of the virtues of the nervous system by looking at its vices. These are too numerous to be detailed, including everything from imperfect perceptual, memory, and processing systems, through to tendencies of complex nervous systems to become unstable or “insane.” But one very general form of nervous system failure is worth discussing if only briefly: addiction.2

Addiction always involves inflexibility of the nervous system, an inability to readjust for the good of the whole organism. A classic example is often described in evolution textbooks, although it is not recognized as a matter of addiction: the extinction of the Irish elk. Although it is impossible to tell at this time with certainty, it is usually thought that the Irish elk became extinct after the last ice age largely because its antlers became too large. Fossilized elk remains with antlers up to 4 m (13 feet) across have been found. Presumably these overlarge antlers made it more difficult for the elk to escape predators (including human predators)—an animal with such large antlers cannot easily hide in the forest, for instance. But why did the elk’s antlers become so large? Why was there not selection pressure against such large antlers? We would expect that natural selection would favor animals with smaller antlers, and thus that the elk would have gradually developed smaller antlers. Why did natural selection fail in this case?

The answer lies in the inflexibility of the elk’s nervous system, and hence its inability to learn. One essential role of the nervous system is to orchestrate reproductive activity. Females should find males sexually attractive, and males should return the favor. This requires a considerable amount of neural sophistication: the nervous system that must process incoming visual, olfactory, auditory, and tactile information in order that an animal can recognize sexually appropriate members of its species and initiate the proper behaviors. In addition, males and females should also be wired up neurally, so to speak, in such a way as to prefer healthier, stronger, faster mates. Among many species of deer, moose, and elk, antler size becomes the standard of sexual desirability. The general health of a male strongly correlates with the size of its antlers. In the case of the Irish elk, it is hypothesized that females preferred males with larger antlers, which led to runaway growth in antler size and thereby the eventual demise of the species. The problem was that the neural mechanisms of sexual preference were written in the genes of these elk, and changing these genes is a very slow process. Genetic change requires mutation and selection, and the first of these processes may be extremely slow. Neural structures underlying instincts, especially instincts essential to survival, tend to be robust and redundant: In short, they are inflexible. They cannot be adjusted very quickly. Because the elk were unable to learn new sexual behaviors within their lifetime, they had no choice but to follow the dictates of their instincts, even as these led to their extinction.

It is not mere metaphor to say that the Irish elk were addicted to antler size in their sexual behavior, since this behavior was in all essential respects just like other addictive behavior, such as drug abuse. Substances such as alcohol, nicotine, cocaine, and the opiates activate the natural reward systems of the body, strongly reinforcing maladaptive behavior. Because the neural systems of reward are deeply integrated into the human genome, it is very difficult to counter the use of these substances, even in the face of obvious damage to the body. Learning has only a superficial effect on the instinctive mechanisms of reward, and it is this inflexibility that leads to maladaptive behavior—just as in the case of the ill-starred Irish elk. Human beings currently suffer from a number of forms of addiction. Let us consider one of these: food addiction. Because periodic food shortages were the norm over most of human history, those of our ancestors who ate more food than was immediately needed built up stores of fat, and this enabled them to survive food shortages better than their less hungry, thinner friends. Thus, natural selection preferred big eaters over moderate eaters, with the result that most human beings will eat even when they are not hungry and the body has no need for nourishment. Since science and technology have largely eliminated food shortages, obesity has become a greater hazard to human beings than famine or undernourishment. Because the neural mechanisms controlling hunger are embedded in our genes, hunger is insensitive to learning. Even in the face of obvious bodily damage, the desire to eat may prevail.

This is relevant to the issues at hand in two ways. First, human beings consume more food than they need, so they engage in needless agricultural behavior. So when it comes to natural goods, it must be noted that food is not always a matter of need or necessity for human beings but is sometimes a matter of excess desire over and above what is necessary. Nor are our other desires and behavior immune to such addictive syndromes. Clothing, shelter, and mobility are also natural necessities that are subject to the development of addiction as well: Houses and clothing may be larger and more elaborate than needed. It is always a natural good to satisfy a desire, so it is possible that sometimes eating more than is necessary, wearing clothes that are nicer than is necessary, and so on, may be a good thing to do. For example, humans mark weddings and other with socially important events with ceremonial feasting and ceremonial dress. It is also possible that sometimes these things are bad things to do.

However, these are ethical issues that would take us beyond the scope of this book, and for that reason we must mainly restrict our attention to natural necessities: natural goods that are naturally desired and which are also required for survival or the avoidance of pain (or both). As we noted in Section 9.1, there is no sharp boundary between natural desires and natural necessities, but one gradually shades into the other. Thus, addictive behavior, one main vice of nervous systems, is a matter of degree. When biologists determine what the daily minimum food requirements are for a given species, they do not take the bare minimum required to permit survival but that level that allows the animal to grow to its full size, be strong, be active, be resilient to temporary shortages, and so on. Similarly, when we speak of natural necessities, we do not mean bare necessities for mere survival, but what is necessary for good health, activity, and development. A well-tuned nervous system inclines an animal to nearly-optimal levels of food intake, activity, rest, growth, and so on. A nervous system for the planet would do this for life on the planet in general, including human life as one important instance, particularly if humankind embodied that nervous system. One key to remaining well tuned is the ability to monitor sufficiency and excess as they crop up, and the ability to retune as needed.

Second, the widespread human addiction to overeating illustrates the need of nervous systems for flexibility and learning, especially when changes in behavior are required to handle changes in the world around us. For example, at this time there is a general tendency of environmentalists toward inflexible rejection of technology and technological solutions to the problems we face. Environmentalists are addicted to rejecting technology and blaming it for environmental problems. On the other side of the issue, lovers of technology, technophiles, tend to accept new technology inflexibly and to seek technological solutions to every problem. Rather than eating less, the technophile may expect scientists to develop low-calorie foods. As inflexible tendencies, both the environmentalist’s rejection of technology and the technophiles demand for it are forms of addiction, and hence are species of vice. Of course, all nervous systems are imperfect and will make mistakes. The deer may not notice the wolves lying in wait at the edges of the waterhole, or the wolves may not realize that they are not well hidden and so can be spotted by the deer. To be susceptible to error is not a vice, or else all nervous systems would be riddled with vice. A vice is a particular form of error, an error to which a system is particularly prone.

To every vice there is a corresponding virtue. The opposite of the vice of addiction is the ability of nervous systems to learn, to be responsive to changes, to recognize failures and do something about them. Developing techniques to enable timely and efficient learning has been a main goal of philosophy right from the start. Energetic debate, or dialectic, has generally been the preferred method. In the dialectical method, a problem or question is identified, and someone states a thesis that solves the problem wholly or partially. Then someone vigorously tries to reveal the faults in the thesis. The thesis may be defended, revised, or abandoned, and the process then continues. Dialectic can be internalized in a form of meditation in which a single per- son internalizes dialectical debate by alternating between the two roles of advancing theses and criticizing them. Use of this method has solved many of our scientific, medical, ethical, legal, and political problems, and has led to specific forms of the dialectical method in each of these fields. Within the sciences, dialectical debate is carried on in universities, laboratories, conferences, and scholarly journals. A legal trial is a specific formalized version of the dialectical method developed to determine questions of guilt and innocence.

The philosophy of nature needs to develop its own set of techniques and discussions, with its own set of generally accepted results, its own crucial questions, its ongoing debates, its test cases, and so on. This book, including the theses it presents, is offered as a step in this direction. Among the theses it puts forward is the idea that humankind accept its environmental responsibilities by providing the Earth with the sorts of information-processing that nervous systems provide animals. If this proposed information-processing system is to succeed, it must avoid the trap of addiction, and so must be ready, willing, and able to learn at all times. I would further suggest, therefore, that the system employ the dialectical method.


Now that we are going through this historical role reversal, we need to reconceive our struggle with nature. We would like to cooperate with nature, but we cannot cooperate with nature unless we have an idea where the limits of sacrifice on either side are to be drawn. For us to cooperate is for us to make an effort, to give of our own time and therefore our own lives, on behalf of nature. When push comes to shove, just how much should humankind sacrifice in order that nature as a whole may flourish? How much should nature as a whole sacrifice in order that we may flourish? Would it ever be right, for example, for another species to be sacrificed so that we can survive? Can every tension between our interests and those of other species be resolved harmoniously? Probably not. To say otherwise would be sheer romanticism or presumption. But if universal harmony between us and all other living systems cannot be assumed, how is the resulting conflict to be decided?

Let us grant that environmentalists are right about one thing, specifically that it is possible for human beings to harm nature. Does it follow that human interests can clash with the interests of nature as a whole? Sometimes people harm nature by following what they think are their interests. Human beings did pollute the air and the water in the past, and still continue to do so to some extent. But doing so was not actually in the interests of human beings as a group. Certainly, some humans may have benefited, but pollution hurt many humans as well. Pollution of nature by human beings is analogous to cigarette smoking in human beings. It is not good for the human being as a whole to smoke, although it is very satisfying to the nervous system. Partly because the lungs are poorly enervated and we do not feel pain in our lungs proportional to the damage that smoking causes, and partly because nicotine is experienced as a reward by the nervous system, human beings will smoke, even though they know it harms their body. Humans are similarly insensitive to damage to the body of nature and do not feel bodily pain when nature is harmed, so they polluted the water and air that they themselves drank and breathed. But when the smoker becomes ill, or when people begin dying in numbers, the mistake is realized: thinking that the interests of humankind and nature, or the brain and the body, could actually disagree in fact.

Humankind cannot exist without the body of nature, and a brain cannot exist without its body. The converse is possible, however. A body can exist without a complete brain, and nature can exist without human beings, as it indeed had done for billions of years before it gave birth to our species. There is something profoundly sad about a human body that exists without consciousness. The body of a person who is brain dead or in an irreversible coma is a waste, a tragic loss of what might have been. Is there nothing sad about the body of nature living on without any awareness of its own existence, no awareness of whether it is in good health or poor, no ability to sense danger or promise, no ability to take action on its own behalf? Human beings never have been Earth’s nervous system. When human beings harm nature, they do not do it as Earth’s nervous system involved in addictive behavior. They do it as one species among the many others that nature has created, a species that has to compete for survival within nature, contending not only with these other species (diseases, predators, competitors for food and shelter, thorns, poisonous insects, etc.) but the elements as well (wind, rain, cold, tidal waves, wildfires, etc.). We have taken our struggle within nature to extremes, with the result that we have clashed with nature itself. And we have come—or at least are coming—to the realization that we cannot hurt nature itself without hurting ourselves.

So it is a type truth (of the sort introduced in Section 7.5) that our interests cannot actually diverge from the interests of nature, and for the same reason that it is a type truth that the interests of the brain cannot actually conflict with the interests of the rest of the body: Neither can exist apart from the natural body to which they are matched. It is worth observing that a specific sort of brain goes with a specific sort of body. The brain of a fish cannot plug into our body, nor yours into it. Neither the metabolism nor the information processing will match. Indeed, your specific brain is matched to your specific body. Your brain knows how to walk in your body, not in another body. And what holds for walking also holds for talking and many other things as well. In just the same way, we are matched to the Earth, at least at the metabolic level. We are built to live in a specific mix of gases in a specific range of temperature and pressure and gravitational force, and to eat specific sorts of foods, and so on, all of which are present here on Earth. All of these elementary conditions and biological conditions of our existence are in turn connected to the physics and chemistry of this planet. So in the end we, too, are matched to Earth even in its physical and chemical nature, its distance from the Sun, its seasons, and so on. So we are deeply matched to Earth at the metabolic level. It is for this reason that we cannot survive without this planet.3

But unlike the match of brain and body, we are not matched to this planet in terms of information processing—although we could be. It is conceivable that we could become so valuable to nature that it would be sad for nature to go on without us, in the same way that it is sad for a body to go on living without its brain. We have so far spent our physical and intellectual energies struggling with other players on the natural stage to attain food, clothing, and shelter. We have struggled to gain a measure of natural freedom, freedom from excessive work, suffering, and death. With this freedom we now can contemplate a role that has been impossible up to the present moment: working for the good of nature, not as a sacrifice of our own interests and destiny, but as a fulfillment of them. Just as what is bad for nature as a whole is bad for us, what is good for nature as a whole is good for us—or would be if we were to become a new and useful system within nature as a whole: an information-processing system dedicated to the good of the whole. This is not a task to be lightly undertaken, for nervous systems can go wrong, as we know in our own case. Nervous systems can become motivated to do things that are not in the interests of the body and hence not in their own interest. The human nervous system is often inclined toward overeating, an understandable result of natural selection under conditions where famine was the main Malthusian check on our population. Understandable, yes, and arguably forgivable, but a flaw nevertheless in our very nature.

If we contemplate becoming Earth’s information-processing system—and arguably this is a process that is as a matter of fact under way already—we must be on our guard against this sort of failure. We must learn from our mistakes. The current struggle of humankind with the threat of global warming presupposes both that we are becoming Earth’s nervous system and that we are prone to mistakes which are similar (or functionally isomorphic) to addiction. Both those who warn that we must stop using fossil fuels and those who think the warning is alarmist base their stance upon information humankind has gathered about the climate. Both assume that we are capable of having significant effects upon nature for either good or ill. Both assume that we can use our intelligence and our information to act for the good if we choose to do so. Thus, everyone agrees that we can perform the three natural functions of a nervous system: Collect information relevant to Earth as a whole, process it in light of Earth’s interests, and act on that basis. If that is correct, we must engage in an ongoing study of how such systems fail. We do not need a defeatist fascination with failure, however. We need to study how nervous systems fail in order to avoid these snares and pitfalls and thus succeed.

We can take a lesson from Immanuel Kant in our study of these snares and pitfalls. Kant conceived of human immorality as a form of irrationality. A person who steals something steals it because he or she wants to own it. That is obvious, yet it holds an implicit contradiction in values. On the one hand, the thief has no respect for personal property, as proven by the fact that the thief takes the property of others. On the other hand, however, the thief steals to enjoy the benefits of ownership. Bread is stolen so that it can be eaten, money is stolen so that it can be spent, and so on. Stealing works only because people generally respect property, so thieves can enjoy owning what they steal. Lying involves the same contradiction, for the lie is told in order that it will be believed. But lies are believed only because most of the time people tell the truth. If people lied all the time, lying itself would be impossible, for language would simply cease to have any meaning. If people stole things all the time, stealing would be impossible, for ownership would cease to have any meaning. So immorality is possible only when someone makes an exception to the rule in their own case, while expecting everyone else to follow the rule. Kant’s advice to us is to ask whether the rule we follow in acting could be followed by everyone else, as though it were a law of nature. If it cannot, we know that the act is immoral.4

From the Kantian point of view, addiction is a normal case of immorality because it is irrational in the normal way. In addiction the nervous system persists in a behavior that clashes with the interests of the whole body, even while it depends of the rest of the body acting for the interests of the body as a whole. Among the systems of the body, it makes an exception to the rules in its own case, and the fruits of this exception can only be enjoyed because the other systems follow the rule. If all of the other systems clashed with the interests of the body as a whole, the body would die, and it would become impossible for the nervous system to gain its unfair advantage in the first place. At the level of type truths, the irrationality or immorality within a society is closely analogous (or functionally isomorphic) to the irrationality of addictive behavior. Plato explains this sort of behavior as a trick of perspective, of the close looking larger than what is farther away. Surely there is something in the idea that taking the longer, broader view is hard to do, although it is the right thing to do. Deferred rewards do not motivate us like immediate rewards, and this is not always irrational. “Seize the day!” sometimes saves the day. A bird in the hand is worth two in the bush. Hobbes thought that the stability of voluntary collectivities formed for mutual advantage was subject to systematic failures because cheating confers advantages. Surely there is some truth to this and to Hobbes’s idea that cheating must be penalized.

What is not often recognized is that the laws against cheating only apply in a categorically well-defined world, where the boundaries between types are sharp. In fact, constant low levels of cheating are the norm in nature. Stealing and lying and addiction persist despite their irrationality. We always have thieves and liars among us. The cuckoos and the starlings continue to lay their eggs in the nests of songbirds, even though their behavior is inherently unstable and if too successful would eliminate the songbirds on which they rely.5 And we do not want to realize that it would not always be a good thing if the laws were strictly enforced. Sometimes the poor must steal bread to survive so that they can farm the fields from which the bread comes. When your neighbor comes to you in a fit of anger, determined to murder his wife, it might be best for you to lie when he asks you whether you know where she is. We might do better to think of a tension that must be kept in harmony. Within nature, we see that the laws, although perfectly universal, do not produce simplistic effects. Although gravity is universal, it is not true that what goes up must come down. Gravity is but one force among many in nature’s physical repertoire. Given sufficient acceleration, something can go into orbit and stay there just as long as you like. It can even achieve escape velocity and never return. The need for someone or some species to survive might sometimes overrule the general necessity for property or honesty.

If we think of the laws of natural collectivities, the sorts of laws that give rise to multicellular animals, for example, as type-level laws, we might do better. Certainly that is what observation shows us is nature’s own way of doing things. Perhaps it is flawed. We have no guarantee that it is perfect. On the other hand, we would do well to at least observe to see whether it may not have something to teach us. What we see is dazzling complexity. The laws of nature may be expressed in a notationally brief way, but they give rise to the fractal complexity of the life we see around us. Life itself is the most complex phenomenon that we have witnessed in the universe. Virtually the entire observable universe is deadly boring. There are endless light years of empty space, occasionally punctuated by a star, which consists of mile after endless mile of hydrogen gas. Sometimes a star (of the second or third generation) will have a chemically complex planet circling it. Although the planet itself contains mile after mile of air or water or molten rock, a tiny, tiny fraction of the available volume is occupied by living cells, which are more complex than the world around them. These cells combine to form more complex things, multicellular animals, which in turn combine to form more complex things, such as kinship groups and countries, and so on. Although the laws are simple, their effect is anything but.

Perhaps in this context, where simplicity breeds complexity, we should think of the simple laws of nature, whether physical or moral (the latter stemming from nature’s rules for collectivities), as creating a harmonious tension. Nature’s creativity seems to rely upon setting forces against each other in a natural dialectic. The dialectic itself is a process, an ongoing exchange marked by conception, birth, growth, maturity, and death. If Earth is to become an entity, a sort of multiorganismic animal on the model of multicellular organisms, it is now only at the stage of conception, or even pre-conception. Global entities of science, economics, and governance do exist, corresponding to the senses, metabolism, and motor control mechanisms of humankind. But global humanity is only a newborn entity, or a newly forming entity that is gradually assimilating its parts into something like a coherent whole. So we must not assume goals that are more appropriate to more mature stages of life—although we not only may, but must conceive them as we can.

Whereas forecasts of human population growth used to reach 20 billion for the twenty-first century, it is now generally agreed that population will peak at around 9 billion in about 2075 (see Figure I.1 in the Introduction). It now appears that given material security and access to birth control, women on average tend to have fewer than two children each, which is well below the 2.2 children each required to sustain the population. Assuming that human population will be on the decline by 2100, how low should it go?

Zero. David Foreman, founding member of the environmentalist group Earth First! (a name that nicely expresses environmentalism’s transcendent value), has been un- usually candid in expressing just what humanity’s environmental effect has been. Although environmentalists hate to admit it, and immediately get a harsh reaction when they do, the fact is that Foreman is right when he says “Humanity is the cancer of nature. . . . The optimum human population of Earth is zero” (Foreman 1998b). The idea that humanity is a cancer is not just a metaphor, and is often recognized by the best environmentalists. David Suzuki, a renowned environmentalist, says: “We are overrunning the planet like an out-of-control malignancy” (Suzuki 1994, pp. 18–19). Thomas Lovejoy, an environmentalist with impressive academic credentials, has observed:6 “The planet is about to break out with fever, indeed it may already have, and we [human beings] are the disease. We should be at war with ourselves…” (Ray et al. 1990). Niles Eldredge, a renowned biologist and environmentalist, has diagnosed this human disease that saps nature’s strength and threatens its very existence: “Humans do not live with nature but outside it. Homo sapiens became the first species to stop living inside local ecosystems. . . . Humans do not live with nature but outside it. . . . Indeed, to develop agriculture is essentially to declare war on ecosystems” (Eldredge 2001).

We do not want to face this very unpleasant truth, but unpleasant truth is the truth nonetheless: Our existence is diametrically opposed to the health of the environment. We are the disease that afflicts the natural world. So if we truly care about the natural world and seek the health of the environment, we must cure this disease. What this entails, as unpleasant as it may sound, is that we must graciously exit from the scene. And it will not actually be painful to do so, after all. In any case, it is now clear that human beings do not want to go to all the trouble of having and raising children. As numerous population data show, given access to birth control, human fertility falls below the rate required for replacement. All we need to do is let this trend take its natural course. No one will be asked to give up their life. Everyone will live just as they are inclined to live. And we can all go to sleep at night knowing that we are doing not only the right thing, but the noble thing.

Not Zero. The often expressed idea that human beings are an out-of-control growth similar to a cancerous malignancy is a hasty conclusion adopted merely because it so nicely expresses environmentalists’ antihuman bias. It is, however, based on two premises that are not usually made explicit, are never examined, and are false.

The first premise is that the human economy demands endless growth and this growth demands ever greater use of environmental resources. This idea is based on a fundamental mistake. Even if we assume that the human economy must grow in order to survive, economic growth refers to growth of economic value, not growth of the total amount of physical substance employed in the economy. For example, the value of your house may well go up (this is a quite common occurrence), and this would be economic growth, even though there was no physical growth in your house and no increase in the amount of environmental materials that compose it. As was discussed briefly toward the end of Case Study 8 in Chapter 7, much global economic growth involves such things as electronics, cell phones, personal computers, and music players, which have very high value but require very small amounts of physical materials.

The second premise of the idea that humanity is out of control is population growth itself. When Foreman, Suzuki, Lovejoy, and the rest put forth the human cancer hypothesis, it was very commonly believed that human population growth was out of control, a belief that they themselves did much to promote. Paul Ehrlich, another prominent environmentalist with impressive academic credentials, is the author of the famous and highly influential book The Population Bomb (Ehrlich 1968), which predicted apocalyptic consequences due to unrestrained population growth. This Malthusian prediction turned out to be false, as current population trends prove. The population bomb was a metaphor that failed to detonate. It is easy to be beguiled by the extrapolation of trends, and environmentalists are not immune to this weakness.

So there is no reason for us to commit collective suicide, no matter how easily this may be done.

Pre-agricultural Levels. Eldredge is still right about one thing: Homo sapiens is profoundly different from all other species that we see around us in the natural world—so different that we are, in effect, unnatural. It is because of our unnaturalness that we have created the ecological crisis that is going to destroy not only us but the rest of the life on this planet if we do not change our ways. He is also right that the crucial step that we took and which threw us off the natural path we should have followed was the development of agriculture. It was at that point that our destruction of the environment began, and it has continued ever since. The only conclusion we can draw is that we must reduce our environmental impact to the level it would have had if we had maintained our pre-agricultural form of life and our natural population.

Not Pre-agricultural Levels. That would require reduction of our numbers by something like a thousandfold (it is typically estimated that there were no more than 5 million people at the end of the last ice age, whereas there are currently some 6 billion of us). In addition, it would mean drastically reducing our use of environmental resources as well. All of the great cities of the world would have to disappear: Mexico City, New York, Rio de Janeiro, Paris, Peking, Tokyo, London, Toronto, Hong Kong, Singapore, Rome, Cairo. The rich culture these cities support—their art, their architecture, their dance, theater, festivals, sporting events, food—would also have to disappear or be reduced to some vestigial form. Science and technology would also have to disappear, since our exploration of the universe depends on large populations from which to draw and train expert personnel, and on the resources such populations provide. If we returned to pre-agricultural population levels, we would be reduced to curators of past riches, tending huge bodies of art, history, literature, music, and science, without the people and resources to comprehend it, let alone to keep it alive and developing.

Aside from the question of whether this is what we really want (and surely it is not), it does not even appear to be sustainable. In the long run our arts and our sciences would die out, and we would even forget our history as we once again became nothing more than a set of isolated groups that had little more in common with each other than mutual suspicion and hostility. The irony is that given human nature, our natural intelligence would once again assert itself, and we would simply begin the process that brought us to this point all over again. We would develop agriculture, technology, science, and finally would find ourselves in much the same situation as we are now.

1 or 2 Billion. We must aim for a population that is sustainable. According to most estimates, that is somewhere between 1 and 2 billion if we assume the level of resource consumption of the average U.S. citizen (Eldredge 1998, p. 184; Erickson 2000). This level would permit us to maintain some of our great cities, our culture, our science, and our technology without endangering the natural environment upon which it all depends.

Not 1 or 2 Billion. This level is the maximum carrying capacity of the Earth assuming that we maintain the resource consumption at current U.S. levels. But this scenario also continues to place the maximum possible stress on the natural environment indefinitely. This is not permissible from the point of view of environmental ethics. The natural environment must be permitted, indeed encouraged, to thrive, not just survive.

The Question Must Remain Open. Case studies are fine, and this discussion should be encouraged, but we must not assume that every question we can ask has a definitive answer once and for all. The hallmark of intelligence is adaptability. The intelligence of the robin hunting for breakfast for its brood does not consist in knowing in advance where the worms are. Instead, it employs a flexible strategy, or better yet, a flexible set of strategies, that will permit it to find the worms it needs under as yet undetermined circumstances. If there is a cat prowling about the spot where it normally gets its breakfast, it will be prepared to look somewhere else. If its own territory turns out to be unusable due to a flood, it must, and will, be ready to make a foray into the territory of the robin next door. If we are intelligent, we will not try to forecast every event before it happens. The robin does not need to know in advanced that a goshawk is hunting for it in order to duck the instant it catches a glimpse of it. We must be prepared to change our course in just this way.

Yes, we must achieve a population that is sustainable, but there is much debate about just what that means and just what the actual sustainable population is under any given definition. Joel E. Cohen, head of the Laboratory of Populations at The Rockefeller University, whose studies (1995a, 1995b) of the Earth’s carrying capacity are considered authoritative, comes to a very different conclusion from the 1 to 2 billion figure: “The fact is that no single number exists to answer ‘how many people can the earth support?’ because human carrying capacity is dynamic and uncertain” (Cohen 2003). As we have seen earlier, sometimes science tells us that a particular quantity is unpredictable (see Section 6.6); the maximum human population is just such a quantity. Why? “The capacity depends on natural constraints and human choices, which are not captured by the ecological notions of carrying capacity we use for nonhumans” (ibid.). So the maximum human population depends on human choices. Which choices? “We must consider in our calculations the interactions of such constraints as food, water and livable land and choices about economies, environment, values and politics” (ibid.). Cohen is saying that sustainable population levels are not fixed in advance, but are largely chosen by us, which implies that they are a function of human values and so can best be determined by employing the sort of intelligence that is manifested in adaptability.

Yes, we must also sustain human culture, our science, technology, arts, architecture, dance, athletics—indeed, everything that makes us human. Contrary to what many environmentalists say, we are not unnatural and we have just as much right to exist in the ways we find natural as does any other species. Contrary to the gap between us and the natural world that is implicit in the distinction between humankind and the environment, and which is therefore implicit in environmentalism itself, Homo sapiens is, absolutely and without doubt, part of nature. We spring from the same source as every other species and continue to be sustained by it. Human nature is part of nature as a whole.

So we must support not merely the sustainability of humankind and the rest of living-kind, but our joint prosperity and flourishing. This means that we must keep our eyes and our minds open, and make the adjustments in-flight that are required, as they are required.


For the newborn, survival is job one. We find ourselves, in Hobbes’s charming words, in a state of nature. There is no harmony among the forces in contention within nature. There is no overall equilibrium, but a process of ongoing change. We have opened our eyes to discover that we are orphans in a jungle that is red in tooth and claw. Nature itself is indifferent to us, and places us in Earth’s arena among millions of species that it has equally favored with existence. We have been blessed with quick wits and nimble hands, and this has given us a temporary advantage in fending off attacks and getting life’s necessities. But every blessing is also a danger, and we have learned of good and evil by practical experience. We have begun to understand the advantages of transcending the warfare of each against all that characterizes the state of nature. We have begun to realize the kernel of truth in Hobbes’ first law of nature, that even while we cannot surrender the advantages of warfare unilaterally, it is in our interest to join with our adversaries to create a mutually beneficial state of peace. In the process we must remember that at this point everything is fair, for there are no rules yet, and there is no peace. If we are wiped out or brought low by plague, famine, or meteorite impact, we cannot even lament that this is unfair, just so darned unfair. For us, survival is job one.

For this reason, we should first attend to our natural needs, the necessities of our existence. When we are more mature, we can move on to questions of virtue and higher goals. We have discovered that our necessities depend on the rest of nature and its necessities. So for now we must concern ourselves with simpler things. Those who propose that we concern ourselves with such things as the integrity, stability, and beauty of nature (Callicott’s expression of the romantic ideal of preagricultural wilderness) have gotten way ahead of themselves. They have provided us with concepts that we are anxious to examine and must eventually turn this way and that so that we can understand them. But at this point it would be arrogant for us to change nature in such a way that it seems more beautiful to some of us. What is so special about a world in which there is nothing but wilderness?

If it is stability we seek, why not stabilize the current state of nature, complete with our farms, fields, cities, and space stations? These are no less natural than ant colonies, beaver ponds, or jungles, and are a product of the fully integrated processes of nature just as they are. Why should we think that the state of nature at the end of the last ice age, just before there were farms, fields, cities, and space stations, had more integrity than its current state? And if it did have such beauty, stability, and integrity, surely what flowed out of this state and this state alone must also have the same stability, beauty, and integrity. Or perhaps we should just drop our pretensions and admit that the only stable feature of nature is permanent evolution, that its beauty is in our eyes and is matched by its awe, and that its integrity is matched by its destructiveness. It destroys everything that it creates.

Our first concern, naturally, is that it not destroy us. This is not a matter of our rights, because nature does not give us rights—or anyone or anything else rights. It gives us existence and that is all, just as it does for everything else that exists. This existential equality is the full extent of our rights and the full measure of nature’s concern for us. Our survival depends on the nature and viability of Earth’s living systems. So if we are to survive, we must pay attention to this dependence. Our survival depends on seeing ourselves as part of the whole system of life on Earth. So our neonate need to survive pushes us toward a special role in the system: We can provide it with the same advantages that it has provided us. This is not a matter of treating everything in nature as sacrosanct. Survival requires destruction. Entropy can decrease locally only at the expense of at least as much increased entropy globally. Predators destroy their prey, forests advance by destroying the barren ground, and fields advance by annihilating the bare prairie. Even if we adopted the plants’ strategy of rooting ourselves in one place, we would destroy the plants that would have otherwise lived on the spot that we appropriate for our own. Our business is survival, not the elimination of strife or suffering. One day, perhaps, in a distant future we might take on such lofty goals, assuming that they are not somehow illusory. In the meantime, we must play by nature’s rules, whereby every act of creation is matched by an act of destruction. We must find our survival within this tension.


The fact that individual Homo sapiens can feel natural sympathy for individuals from species other than their own, even for those which are troublesome to them, is a very rare ability. It makes it possible for us to perform a unique role for life on Earth. It also requires a bit of explanation.

The source of our sympathy is our social nature, the very thing that has led to global human structures (whether economical, political, or ecological) that are influencing the natural environment, and which have the potential for great harm or great good in the coming century. As discussed in Section 11.5, human beings cooperate in order to survive and reproduce, and the way this is achieved is by means of instinctive feelings. Because it gives us an advantage in the evolutionary process, a mother will fight to protect her young. We are often accused of being a fallen race, of having a natural inclination to evil. In particular, we are often said to be selfish. This is true, but it overlooks the fact that we are usually selfish not for ourselves alone but for those we love, in particular our children. Indeed, we are naturally prone to a variety of errors, but on the face of it unselfishness seems to trump selfishness. A father who wins a kingdom but loses his son and alienates his daughter will feel a huge gap in his happiness. A mother who refuses to donate money to charities will happily spend it on her daughter’s wedding dress. A son will go to war to protect his family. Indeed, if it were not for the ready willingness of people to fight to the death for the ones they love, it would be difficult to raise armies ready and willing to wage war.

Our unselfishness, like our selfishness, is the product of an evolutionary struggle in which the need to survive and prosper sometimes required us to cooperate and sometimes to compete with our fellow human beings. Both of these needs were partially satisfied by giving us feelings, feelings of sympathy and feelings of selfishness. Generally speaking, our feelings of sympathy are strongest for those who are closest to us, because over the millennia those families that felt like sticking together have survived and prospered much more than those that did not. We are generally closest to our mother, father, brothers, and sisters. When they cry, we feel pain, when they laugh we feel like laughing even if we do not know what it is that is supposed to be funny. Our friends become like family to us, and we will take pains to save them pain. When times are good, our sympathies broaden, until they include our neighbors, our town, our country. In good times there is no need for violent competition with our neighbors, townsmen, countrymen, so we cooperate in a larger group and reserve our pooled violence for those who would attack us from the outside. Their pain feels like our pain, their joys are our joys. The twentieth century saw this pattern of ever-larger groups fighting ever-larger wars come to a nuclear stalemate.

We still take pride when our country wins gold medals in the Olympic games, but we would feel ashamed if we thought our country was sacrificing its sons and daughters in an unjust war. At the moment, the countries armed with nuclear weapons spend much, if not most, of their political and military effort on defusing the risk of war in nonnuclear conflicts of smaller scale. This may well be only a passing phase, and the risk remains of larger, more damaging wars than even those of the twentieth century. It should not be just a passing phase, and we should do whatever we can to secure peace among humankind. This is something that we owe not only to ourselves, but to Earth as a whole. This is enlightened selfishness, the selfishness of cooperation. It is entirely in our interests to keep the life of this planet healthy, vibrant, resilient, and safe. Safety requires intelligence, and intelligence requires data. We need to be the eyes and ears and brain of the planet. We need to develop our power to act on behalf of us all, not just ourselves but living things in general. We need to become the hands and feet of the Earth and become ready to walk or work as needed. We need to focus our competitive feelings on the largest and most worthy adversary we have ever faced: the uncaring physical universe.

The uncaring physical universe is nothing other than nature as a whole. On the one hand, the physical universe brought this living Earth into existence, and on the other, it has visited a series of catastrophes upon it as well. The relationship of the Earth to nature as a whole mirrors the relationship of any species to the entire system of life in which it finds itself. On the one hand, nature gives birth to us, and on the other, we must struggle with both the elements and with other living things in order to survive. Within the system of life on Earth, it is eat or be eaten, crowd out the others or be crowded out yourself. Each plant must either reach for the Sun or else be shaded by those that do. Competition is everywhere, even with your own kind. Your own kind, after all, wants the same things that you do. Their food could be your food if you can somehow eat it before they do. Unless, of course, there is plenty, in which case the spirit of cooperation prevails. Sympathy for the man or woman who lives far away in a country unlike your own comes easiest on a full stomach after a good night’s sleep. We must secure our own necessities and the necessities of our family before we can worry about people whom we have never met or seen.

So humankind must secure its own necessities before it can care properly about nature as a whole. Our struggle with nature must be won before we can sympathize with our former competitors. We are on the verge of securing natural freedom for nearly all of humankind. Freedom from death, suffering, and excessive work is a necessity if our concern for nature is to be effective. Environmentalists have broad sympathies because they can afford broad sympathies. Poaching wildlife and secretly cutting wood in the forest will remain as long as people have no other way to get food, shelter, or fuel. Everyone needs fire, if only for cooking, warmth, or light, especially if they would like to share and develop sympathy with species other than their own. When human beings are free from the necessity to struggle just to stay alive, when they have the food, clothing, shelter, and freedom from pestilence which permits them to embrace life rather than merely running from death, their sympathies expand in an awe-inspiring way. Unlike dogs or cats or wolves or lions, humans can sympathize with their prey and find themselves unable to kill it. What is so wonderful, we may ask, in killing a deer? Generally, we do not allow hunters to kill does with fawns. Hunters are required to eat the deer they kill, and not just part of it either.

It is easy to say that writers and cartoonists have personified deer, and that is why we are able to sympathize with them. The question remains why it is that Bambi can capture our sympathies, and the answer lies in our ability to see ourselves in others, to identify with them, to feel the way that they do. Human beings have the intelligence and imagination not just to recognize, but to feel, the deep similarities between themselves and other species. Robert Burns, author of the “Ode to a Mouse,” was not the only person who could visualize the joys and sorrows of animals other than the human animal. People can even feel sorry for their houseplants when they forget to water them. Aldo Leopold sympathized with the living land itself, and he was not alone in this, either. This is an ability of Homo sapiens. It is by no means a necessity, but it can be done. Indeed, it can even be overdone, although this too is not a necessity. Sympathy simply is feeling what others feel, which requires that they feel something in the first place. Given that other beings have the capacity for pain or joy, we are not only able to sympathize, but inclined to sympathize—assuming that we are not too emotionally exhausted from struggling to survive. Other species do not have this capacity, but we do. This is a unique ability, and arguably it gives us a unique responsibility to realize the good that this makes possible.

In any case, it provides us with far and away the best qualification of any species for the job of Earth’s nervous system. As Descartes pointed out in his sixth meditation (1641), our minds are not lodged in our bodies like a captain in a ship, because the captain does not feel pain when part of the ship is damaged. We feel pain when our body is damaged, and we feel it where the damage occurs. We also have the ability of the social animal to feel the pain of others, as though they were extensions of our body, as though their hurt were our hurt. We can feel hurt not only in our own body, but in the body of someone we care about. We instinctively say “Ow!” when our children scrape their knees. This is not a matter of faith, but fact. The concept of humankind as Earth’s nervous system, by contrast, is merely a possibility that can be expressed in terms of an analogy with natural processes of integration, in particular the banding together of cells to form multicellular animals capable of seeing, moving, and thinking. Perhaps this possibility is also analogous to becoming wise gardeners of the entire Earth, although we grow in the same garden we tend. Perhaps it is not so different from being wise stewards of the Earth, with the exception that we are self-employed and are among the things we tend. Perhaps it is like being housekeeper and maintenance crew on Spaceship Earth, except that we have no captain to give us orders, so must decide on our own what needs to be done. Even so, we are not the Earth’s captain but merely one system within its body, the one system capable of seeing, thinking, acting, and feeling not just for ourselves but for the entire body.

11.7 A CODE

It is all well and good to recognize that we should accept our responsibility for nature, at least so far as we are able to affect it. It is even permissible within the field of values to conceive of possible futures—no, it is necessary, for that is the only way that any of us can make long-term plans, and we do need a long-term plan. But adding these two pieces together still leaves us basically with an argument to take charge of the planet for its own good. Why should we do this? What is in it for us? Are we to assume that whatever is good for the planet will necessarily be good for us? Maybe doing what is good for the planet will be bad for us. So are we being asked once again to sacrifice ourselves for the good of the environment? If not, what are we being asked to do?

We human beings should flourish, that is what we should do. We should continue to increase our natural freedom, our liberation from death, pain, and drudgery. We should become healthy, wise, powerful, peaceful, and good. We should advance our science and technology. We should seek understanding of the history of life on this planet and how nature works. We should continue to gather whatever news we deem worthy, whether trivial or important, whether from near or from afar, and keep ourselves informed about what is happening in the world we inhabit. We should tell stories, make movies, sing, dance, and play. In addition to all of these wholesome activities, whether scientific, artistic, or athletic, we should eat, drink, and be merry in the proper measure. To sum it all up, we should prosper in the fullest sense of the word and become wealthy in the fullest sense of the word. If we can do all of the things listed above, we will indeed be wealthy in this broad sense—which would be not only to our own good but to the good of life itself.

As we do these things, we must remember that we are here for nature, just as nature is here for us. To balance what we owe nature from what nature owes us, we need a code. I offer one for your consideration. It will consist of six theses which, fortunately, follow directly from those that went before.

Thesis 16 states that nature is not good. This implies that nature can be improved, given that we have the power to act in ways that improve it. It could be, for instance, that we will learn that the elimination of a species of mosquito would actually improve the overall health of the environment by increasing the health and viability of other living things. Only a romantic belief in the ideal balance of nature (contrary to Thesis 12), or the natural perfection of all ecosystems (contrary to Thesis 13), would suggest that this could not be the case. Once we free ourselves from these romantic delusions, it is obvious that not every state of nature all through the history of the universe was ideal. To believe otherwise requires believing that every species that became extinct disappeared at precisely the right instant, and that every new species emerged at precisely the right instant, in a chain of cosmic coincidences that defies common sense. If life is a good thing, many events in Earth’s history were bad since they were dangerous for life itself.

This follows from Thesis 20, that we should embrace our responsibility for the state of nature. Given that we embrace responsibility, it follows that we must have a corresponding freedom of action. Thesis 23 states this freedom in a manner that evokes the contemporary resonance of the concept of rights, just to make its point very clear.7 Our actions can only be guided by our own sense of values—and this entails an enormous responsibility that we must take very seriously. The phrase “do as we choose” in Thesis 23 must not be interpreted as the suggestion that we act arbitrarily or capriciously. On the other hand, Thesis 23 does imply that our right to act is not in any way impeded by any obligations other than those we impose upon ourselves. Because we act as we choose, what we do falls in the domain of ethics and morality and must be seen as either right or wrong. Only by accepting Thesis 23 can we go on to judge the actions of humanity as either right or wrong when it comes to their effects on nature—and of course it is imperative that we do make these judgments. This thesis also says that there is no universal political or moral regime that has imposed any obligation on us with respect to the natural world. Any obligations that we may have to nature can only be self-imposed. As frightening as this fact may be, it is nevertheless true. We must face up to our awesome responsibility, and we can only do this if we realize its dimensions.

In Section 9.2 we discussed briefly the value of life itself and our solidarity with it. The value of life itself does not derive from the supposition that life is always good. Far from it. Life as we know it on Earth tends to generate more pain than pleasure, hence more bad than good, naturally speaking. On the other hand, life is the basis for anything of any value at all. The possibility of any good at all therefore depends on the existence of life. Our preference for life over the nonliving may be said to be biased in favor of ourselves since we are living beings, but so be it. This bias is perfectly reasonable given the necessity of life for the very possibility of goodness. If we are faced with the choice between either preserving certain geological features or else preserving certain life-forms, we should give preference to the life-forms, other things being equal.8 If we are faced with the choice of destroying a stone or destroying a kitten, we should destroy the stone and save the kitten. Hopefully, this is obvious enough.

Thesis 14 observes that pain and pleasure are the basis of natural value, and Thesis 15 notes that only beings capable of pain and pleasure may be harmed or helped. Thesis 25 draws out the central implication of these two prior theses for our values and ethics. To make it plain that more than just bodily pain and pleasure is at issue, Thesis 25 is stated in terms of caring. No event or state of affairs is of any value one way or the other unless someone (i.e., some conscious being) cares about it. The most direct and obvious caring of this form is bodily pain or pleasure, but as we have seen in Sections 9.2, pains and pleasures often extend far beyond their basic bodily forms. Because it is physically painful to be cut by a knife, being threatened with a knife will cause us pain as well, even though the sort of pain it causes is not felt in a part of the body. Since in the end all value will be embodied in pain or pleasure of one form or another, this thesis enjoins us to do the right thing by increasing the good over the bad by paying attention first and foremost to the welfare and interests of those organisms that are capable of pain and pleasure. If we are faced with a choice between preserving a tree, which cannot feel either pain or pleasure, with preserving an animal which can feel pain and pleasure, we must save the animal.

To put it crudely, if we were presented with a choice of preserving either our species or another species, it would be right, other things being equal, to preserve our own. This is not selfish or arrogant, but an obligation that we recognize given our special place in the natural order. Not only do we human beings have the widest range of pains and pleasures, we are also the only organisms capable of comprehending the beauty and awe of nature. Although there are many, many sentient animals capable of pain and pleasure, we are the only ones capable of understanding what a species is, or of recognizing its value. Only human beings can recognize the loss of a species, or take steps to protect it. We are the threads that sew the experiences of other animals together into an organic whole. If it were not for us, the beauty and awe of nature would be wasted possibilities. Just as colors cannot exist unless some being sees them, so too beauty and awe would not exist if we did not see them. We hear the melody that runs through the various and varied sounds of the natural world. We enable ranges of value to emerge that otherwise would not exist. We and we alone are capable of recognizing the significance of nature and of life, and give them meaning. We and we alone have risen above the struggle for existence and can champion nature as a whole and life itself. We and we alone can protect and nurture Earth and its precious cargo of life.

To put it picturesquely, after a long childhood struggle to survive in an indifferent universe, we now find ourselves alone, the only adults on Spaceship Earth. Although there are millions of other species of life on the ship, and whether we like it or not, we are the only species with any chance of figuring out how the ship works. We can do everyone on board a big favor by judiciously learning how to handle the controls and then setting the best course we can. Just what that course should be is a philosophical question that must be answered, and then asked again, and then reanswered and reasked, our understanding unfolding in parallel with the unfolding of the natural universe itself.

  1. As we now know, thanks in large part to the work of Lynn Margulis, the mitochondria that are inside our bodily cells and are essential to our metabolism were once infectious agents that happened to choose a cooperative relationship with us rather than a competitive one, symbiosis rather than conflict. There is evolutionary pressure, to use the currently fashionable concept, for such symbiosis. We would do well to study and appreciate this pressure.
  2. See Foss 1996a for more discussion of addiction.
  3. Of course, individual human beings can exist outside Earth, at least for a time, as astronauts currently do. But humankind—the entire species—cannot, at least for now. So it is a type-level truth that humans cannot survive without Earth because they are so deeply matched to it.
  4. I think that everyone will see the above as a relatively uncontentious reading of Kant, although there are details and problems in the interpretation of Kantian ethics that it does not address. What follows below, by contrast, are a series of implications that are not generally discussed in Kant scholarship.
  5. It is interesting that one explanation of declining songbird numbers in eastern North America is the rise of cowbird numbers due to cattle farming. Like cuckoos and starlings, cowbirds trick other birds into tending their young.
  6. “Dr. Thomas Lovejoy, a Yale University-trained biologist, is Science Advisor to Secretary of Interior Bruce Babbitt and project leader of the National Biological Survey, a comprehensive survey of the nation’s biological resources being undertaken by the U.S. Department of the Interior. He has served as Assistant Secretary of External Affairs at the Smithsonian Institution and as Vice President for Science of the World Wildlife Fund” (the National Center for Public Policy Research, August 24, 1993; http://www.nationalcenter.org/dos7127.htm).
  7. It may be objected that using the terminology of rights in this context is incoherent, since rights have to be granted by actual political entities. On the other hand, however, it could be argued, along with Hobbes (1651), that in a state of nature, prior to any political contract whatever, everything is permitted and nothing obligated: Everyone has the right to do whatever they please. The role of political contracts can only be to restrict this native freedom. Humankind has no contract with the rest of nature, so is under no obligations to nature as a whole. So it does make sense, at least, to speak of our rights in this context. In any case, I am using the word rights in the popular sense, to indicate a moral freedom, the freedom to act, which itself is required in order that our actions are either right or wrong. Thesis 23 states that it is morally correct for us to do as we choose. Unless we do as we choose, our actions fall in the domain of the amoral, and are neither right or wrong. Since we want to take responsibility for our actions, we need to grant Thesis 23.
  8. If destruction of the geological feature hurt living things in some way, other things would not be equal, and we would be called upon to determine the overall best course to follow. It is quite conceivable that even the mere aesthetic satisfaction of human beings would justify the preservation of a geological feature (e.g., a range of mountains or a river) at the expense of the extinction of a species (e.g., a species of insect). We already consider it morally justifiable to destroy the bacterium that causes smallpox in order that human beings not suffer from the horrible disease of smallpox. This presupposes the principle that life-forms are not sacrosanct. Thus, it is at least an open question whether a life-form might be expendable in order to achieve specific human goods, one that cannot be answered by fiat in advance of the facts in any particular case.