Friday, June 07, 2013

Are Tortoises Better Than Goats? Darwinian Ethics in the Galapagos

For some years now, the National Park Service of the Galapagos Islands has sponsored programs for the mass killing of pigs, donkeys, and goats on the islands.  For example, over a five year period, over 140,000 goats were killed on two islands--Santiago and northern Isabela Island.  The killing of these and other animals is justified by the claim that these "invasive" species must be eradicated to protect the "native" species, such as the Galapagos giant tortoises, marine iguanas, and finches.  The goats are so voracious in eating vegetation that is necessary for the diet of the native species that the native animals could eventually be driven to extinction if the goats were not killed.

As an ecotourist looking forward to my first tour of the Galapagos, I agree with this, because I would rather see giant tortoises than goats.  But by what moral standard do I judge that tortoises are more valuable than goats?  The farmers who introduced these goats to the islands might not agree with me.  In fact, in recent years, some of the residents of the islands have staged violent protests against the policies of the National Park Service that threaten their livelihoods.

Darwin observed the drastic environmental changes that can come from introducing goats and other imported species into isolated island.   When he visited the island of St. Helena in the South Pacific on his way back to England on the Beagle, he was surprised by the "English, or rather Welsh character of the scenery" on this island, and he discovered that this was because plants imported from England had driven out the native vegetation.  Goats were introduced in 1502.  And within two hundred years, the feral goats had destroyed all the young trees in many areas, while creating fine pasture land.  In 1731, an order was issued to kill all the stray animals, but by then "the evil was complete and irretrievable" (The Voyage of the Beagle, National Geographic Society, 2004, pp. 432-35).

But why was this "evil"?   After all, in the light of the evolutionary theory that Darwin later developed, we could say that when a new species flourishes at the expense of the native species of an island, this is just survival of the fittest!

By what moral logic do we defend the "native" species of an island against competition from "invasive" species?  The very language of "native" and "invasive" is dubious, since all of the "native" species on the Galapagos are descendants of earlier invaders, who arrived sometime after the islands were formed by volcanic activity.

Sometimes ecologists imply that there is a "balance of nature" that is upset when pristine ecosystems are "invaded" by species that don't belong there.  But if we accept the viewpoint of Darwinian evolution, living nature is never in balance or fixed but ever in a state of flux as species compete with one another, and there is no cosmic order of nature by which we can judge that one species belongs here and another species belongs there.  I would rather see tortoises than goats in the Galapagos.  But that's not because tortoises rank higher in the Great Chain of Being than goats, or because there is some cosmic or divine design by which tortoises belong in the Galapagos and goats do not.

If we think this through, we are led back to one of the major implications of evolutionary science for moral judgment.  If there is no moral cosmology for determining right and wrong--including the proper place or rank for living species--then our moral judgments must be rooted in our human experience--in our human desires.  If the good is desirable, then the good is variable for different species, and there is no cosmic standard of good and beyond beyond the natural desires of each species.

So for Darwin, what the goats did to St. Helena was "evil," because it frustrated his intellectual desire as a natural scientist to see and study the original flora and fauna of that island.  Similarly, the ecotourists will travel thousands of miles to see the tortoises of the Galapagos, and so if they saw that the goats had made the islands inhospitable for the tortoises, they would be disappointed, because they want to see what Darwin saw.

Some environmentalists would complain that I am being too anthropocentric in my environmental ethics, because I am assuming that the value of all living beings is determined by the instrumental value in satisfying human desires.  These environmentalist say that we need an ecocentric or biocentric ethics that recognizes the intrinsic value of all living beings without reference to human desires.  But I find this implausible, and I see it as contradicting the evolutionary science that environmentalists generally accept.

I wrote about this some years ago in a paper on "Aldo Leopold's Human Ecology" (in Charles Rubin, ed., Conservation Reconsidered, Rowman & Littlefield, 2000).  The ecocentric environmentalists claim to be following the lead of Aldo Leopold, particularly in his classic of environmental ethics A Sand County Almanac (1948).  But I argue that this is wrong because Leopold consistently embraced an anthropocentric ethics rooted in the moral-sense tradition of ethical philosophy as developed by Adam Smith and David Hume and adopted by Charles Darwin. 

As the evolved social and moral animals that we are, we can extend our moral concern to nonhuman animals and plants, and perhaps even to whole biotic communities that include soil, water, plants, and other animals, which Leopold called the "land."  But that moral concern will always be anthropocentric in the sense that it is centered in our human desires.  If the "land" has any value for us, it's because it satisfies our intellectual, moral, or aesthetic desires. 

So if we want to eradicate the goats from the Galapagos to protect the native species from their competition, it's because we have been persuaded that this is more desirable for us.  If we disagree--the farmers want to have their goats, and the environmentalists want to have their tortoises--then we will have to struggle to find some mutually desirable resolution.  The environmentalists might persuade the farmers to see the economic benefits of ecotourism.  Or we might strike a balance between some areas devoted to farming and other areas preserved for the ecotourists.

But in no case can we resolve our dispute by appealing to some cosmic or divinely designed order of value that is not rooted in the human good as the humanly desirable.

Thursday, June 06, 2013

James Mackintosh and Darwin's Evolutionary Theory of Morality

On June 23rd, the opening lecture for the Mont Pelerin Society conference on evolution in the Galapagos will be by David Kohn, a Professor Emeritus of the History of Science at Drew University, who is well known for his editing and scholarly studies of Darwin's manuscripts and notebooks.  Although I have not yet seen his paper, his title--"The Scottish Enlightenment, Malthus, and Darwin's Theory of Evolution"--suggests that he will emphasize the influence of Malthus in shaping Darwin's formulation of his theory of evolution.

The influence of Darwin's reading of Thomas Malthus's Essay on the Principle of Population is evident in the notebooks that Darwin began writing shortly after he returned from his voyage on the Beagle in 1836.  By the spring of 1837, Darwin had embraced the idea of the transmutation of species, and he came close to formulating the logic of natural selection (Notebooks, 193, 258).  Then, as he began reading Malthus on September 28, 1838, he grasped for the first time the three steps in the process of natural selection, which he associated with "my Malthusian views" (Notebooks, 375, 397-98, 412-13, 429, 436).  First, traits must be passed down by inheritance from parents to offspring.  Second, those inherited traits must be variable.  Third, there must be a struggle for life so that some inherited variations are favored over others. 

In his Autobiography, Darwin described the influence of reading Malthus in the fall of 1838.
"I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed.  The result of this would be the formation of new species.  Here, then, I had at last got a theory by which to work." (120)
But while this shows the influence of Malthus's book on Darwin's theory of the organic evolution of species, which was published in his Origin of Species in 1859, we need to see the influence of another book on Darwin's theory of the moral evolution of human beings, which was published in his Descent of Man in 1871.  That other book was James Mackintosh's The Progress of Ethical Philosophy 

Mackintosh (1765-1832) was born in Scotland and moved to England in 1787, where he became a prominent Whig member of Parliament, a lawyer, a moral philosopher, and a historian of England.  In his Autobiography Darwin remembered that as a young man of 18, he had met Mackintosh and found him to be "the best converser I ever listened to."  Later, Darwin had heard that Mackintosh had told someone,"There is something in that young man that interests me."  Darwin was pleased by this, and he remembered "that I listened with much interest to everything which he said, for I was as ignorant as a pig about his subjects of history, politics, and moral philosophy" (55).

Mackintosh's book on ethical philosophy was published in 1837, just when Darwin was beginning to formulate his theory of evolution, and Darwin read the book avidly, presumably because he wanted to extend his theory to "history, politics, and moral philosophy."  Darwin marked up his copy of Mackintosh's book and wrote up extensive notes on it (Notebooks, 409, 537, 557-56, 563-64, 587-89, 618-29).  Darwin was most interested in Mackintosh's presentation of the moral philosophy of David Hume, Adam Smith, and other writers of the Scottish Enlightenment.  These ideas from the Scottish moral philosophers shaped the account of the moral sense that Darwin would later publish in The Descent of Man in 1871.

Perhaps the most notable feature of Darwin's notes on moral philosophy from Mackintosh's book is that God is never mentioned and human morality is understood as a product of natural human experience rather than divine moral design.

I suggest that Malthus was to Darwin's theory of organic evolution as Mackintosh was to his theory of moral evolution.  In both cases, Darwin was looking for a theory of spontaneous evolution as opposed to a theory of special creation by divine design.  In both cases, God might be seen as the creator of the laws of nature that made both organic evolution and moral evolution possible, but there was no need for special divine intervention to explain the origin of species or the origin of human morality.

Darwin was reluctant to publish his evolutionary theory of the origin of species--he waited 20 years.  But he was even more reluctant to publish his evolutionary theory of the origin of human morality--he waited over 30 years!

Darwin did indicate that religious beliefs could be important influences on moral evolution.  But he also indicated that moral order could stand on its purely natural grounds even without any religious belief in God as the moral lawgiver.

The possibility of a purely natural morality without religious belief is most clearly stated in Darwin's Autobiography in the section on his religious beliefs.  Darwin explains that while he began in his early life as an orthodox Christian, he gradually turned in the latter half of his life toward "scepticism or rationalism."  He admits that "the mystery of the beginning of all things is insoluble by us," and this leaves an opening for God as the Creator.  But, still, moral life does not require any religious beliefs:
"A man who has no assured and ever present belief in the existence of a personal God or of a future existence with retribution and reward, can have for his rule of life, as far as I can see, only to follow those impulses and instincts which are the strongest or which seem to him the best ones.  A dog acts in this manner, but he does so blindly.  A man, on the other hand, looks forward and backwards, and compares his various feelings, desires and recollections.  He then finds, in accordance with the verdict of the wisest men that the highest satisfaction is derived from following certain impulses, namely the social instincts.  If he acts for the good of others, he will receive the approbation of his fellow men and gain the love of those with whom he lives; and this latter gain undoubtedly is the highest pleasure on this earth.  By degrees it will become intolerable to him to obey his sensuous passions rather than his higher impulses, which when rendered habitual may be almost called instincts.  His reason may occasionally tell him to act in opposition to the opinion of others, whose approbation he will then not receive; but he will still have the solid satisfaction of knowing that he has followed his innermost guide or conscience.--As for myself I believe that I have acted rightly in steadily following and devoting my life to science." (94-95)
That moral order can arise as a largely unintended social order based on natural human experience without divine design is important for Darwin's liberalism, because it means that there is no need to coercively enforce religious beliefs as necessary for social order, which makes possible a liberal pluralist society, in which people having conflicting religious beliefs or even no religious beliefs can live together in peace.