Wednesday, April 29, 2009

The Idea of Nature, Part 2

Nature as Organism and Nature as Machine

The contrast between traditional and modern concepts of nature might be presented as a contrast between visions of nature as an organism and as a machine. For many of the Greek philosophers and medieval theologians, nature was primarily manifest as something that is born and grows. Even for premodern materialists such as Lucretius, nature seems to be a super-organism with a consequent sacred or awe-inspiring character. Although he seeks to remove all religious superstition from the world and present nature as devoid of gods, his poem De rerum natura opens with praise of sky and earth as the father and mother of all living things. In the presence of such a reality--indeed, as part of such a reality--humans are called upon to accept and to live in harmony with it. For Plotinus, throughout "the air, the earth and sea, there are advents of terrestrial, aquatic, and aerial gods so that the world is throughout filled with deity; and on this account is according to the whole of itself the image of the intelligible."

For modern philosophers such as Descartes, however, nature was primarily manifest by inanimate entities that interact as carriers of energy to create complex structures. For Descartes, even living beings are complex machines--plants, animals, and human bodies (including the human brain and nervous system) are all machines.

Such a view of nature as machine undercuts the traditional distinction between nature and artifice. The science of nature as machine yields a technology by which nature as technology can be further molded by human beings to serve human purposes. When Bacon declared that "nature to be commanded must be obeyed," he transforms the premodern basic end in itself of obedience to nature into a mere means for power over nature. Although he argues that all humans can do "is put together or put asunder natural bodies" with "the rest being done by nature working within," for him nature as a mechanical process has already ceased to exhibit much in the way of intrinsic worth.

From the nineteenth-century romantic poets to contemporary deep ecologists, humans have worried that the science and technology of nature as machine brings about first in theory and then in practice, in Bill McKibben's phrase, "the end of nature"--a wholly artificial world controlled by human will with no room left for natural spontaneity or wildness.

In response to this romantic notion of nature and technology in conflict, some people have defended technology as itself natural. All organisms alter their environments in adaptive ways, and many animals build artificial structures. Beavers construct dams, bees fabricate hives, leaf-cutter ants cultivate fungus gardens and herd aphids. Darwin contended that tool-making was common in the animal world, and human technology differed in degree but not in kind.

Some biologists today argue that human technology expresses "niche construction," which is a trait found generally in the living world, because organisms do not just adapt to fixed environments, they also change environments to construct their own niches. There is no fixed "balance of nature," because nature is constantly in flux from the ever-changing forces of both physical and organic causes. For example, the present concentration of oxygen in the atmosphere has arisen from the production of oxygen by photosynthetic organisms. As a consequence, many organisms have evolved a capacity for aerobic respiration and other traits as adaptations to this atmospheric increase in oxygen levels over the course of geological time. Without such a change in the atmosphere brought about by ancient photosynthetic organisms, human beings could never have evolved.

We often think of human culture as a uniquely human realm of artifice transcending nature. But in fact, many animals are capable of cultural learning from other animals, and this cultural learning can be passed down by behavioral inheritance, which creates a process of behavioral inheritance that goes beyond, while also interacting with, genetic inheritance. (A good survey of the evidence for this is presented by Eytan Avital and Eva Jablonka in Animals Traditions: Behavioural Inheritance in Evolution [2000].)

The Morality of Nature

Throughout history, it has been common to appeal to nature as a guide to morality through ideas of "natural right" or "natural law." But the critics of this moral conception of nature complain that this kind of thinking suffers from confusing distinct senses of nature.

Insofar as nature covers the entire order of things, argued John Stuart Mill (in his essay "Nature"), the moral injunction to "follow nature" makes no sense, because humans have no choice in the matter. Everything people do must conform to nature in this abstract, all-encompassing sense. On the other hand, if nature is the spontaneous order of things free from human influence, then "following nature" would be irrational and immoral. It would be irrational, because any human action would alter the course of nature and would thus be unnatural. And it would be immoral, because natural phenomena often have evil effects. Mill declares: "Either it is right that we should kill because nature kills; torture because nature tortures; ruin and devastate because nature does the like; or we ought not to consider at all what nature does, but what it is good to do." Surely, Mill insists, morality requires that we go against the impulses of nature.

Morality is not natural, Mill concludes, because it must be artificially perfected by human cultivation and artifice to satisfy the moral concerns of human beings. Those who argue for a natural moral law mistakenly assume that what is can be the rule and standard for what ought to be. Natural science can reveal the natural facts of existence, but morality must tell humans about the moral values of human life.

This distinction between is and ought, or between facts and values, supports the common distinction between nature and culture. Morality is assumed then to arise not from nature but from culture, because moral norms of right and wrong, good and bad, are products of human cultural artifice. Through science, people can understand nature. And through technology, people can control nature. But to judge the moral ends of scientific understanding and technological control, one must go beyond nature and enter the realm of culture, which is an artificial world of human social contrivance set apart from the natural world. As Remi Brague has shown (in The Wisdom of the World [2003]), Mill's essay on nature manifests the shift from the premodern idea that nature is a model for human action to the modern idea that nature needs to be corrected, not imitated.

As a proponent of "Darwinian natural right," I respond to this by saying that although cosmic nature might be indifferent to moral distinctions, human nature is not. If one can identify some human desires and inclinations as natural and not merely conventional, one can say that the naturally good life is one that satisfies those natural desires and inclinations to conform to some deliberate conception of a whole life well lived. So, for example, if human beings have natural desires for life, for parental care, and for social bonding, then one can judge those beliefs and practices that satisfy these desires as naturally good.

Even Mill accepts this in his utilitarian morality, when he claims that the ultimate good for human beings is the attainment of happiness, which is the fullest satisfaction of their natural desires over a whole life. For example, humans' moral duties to others arise from their natural sentiments as social animals who care for their fellow creatures. Of course, as Mill insists, people's moral values do not spring spontaneously from their inborn human nature, because they need to be cultivated through individual habituation and social customs. But still, as Aristotle said, the cultivation of such virtues is made possible by our natural desires and propensities. It is natural for us to fulfill our nature by nurturing it.

To ponder such questions about the meaning of nature expresses some of the deepest desires of our human nature.

Some of my previous posts on the is/ought question can be found here, here, and here.

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