**5. The legacy of ancient ecology and religion in modern thought: Parallels between ancient stoicism and Humboldt, Darwin, Cuvier, and modern conservationism**

The ancient extinction of silphium seems to reflect the second pole of Stoic thought that we have detailed here. The harvesting and use of silphium was natural and normal, and in that sense good, as part of our biological existence on this Earth. But over-harvesting beyond what was necessary for nourishment showed improper judgment, both about ourselves and the natural world. Because we *can* affect the manifestations of natural processes, humanity has the ability to disturb the balance of nature itself. By disturbing this balance, we act not only non-virtuously from the Stoic perspective but also actively damage nature/god which will, in turn, have damaging consequences for us.

From an ecological point of view, certainly the first consequence – that we sacrifice our own virtue when we take more than is necessary – has continued to bear out time and again over the course of human history. A philosophical orientation toward nature of unfettered use and extraction beyond the survivalist minimum has resulted in cultural attitudes of extraction, imperialism, and a host of hierarchical and bigoted views ranging from neo-colonialism to outright racism. A capitalist ideology of profit maximization for personal gain will doubtless incentivize productivity and capital production, but at the cost of disincentivizing a virtuous relationship, not only with nature but with each other too.

The second ecological consequence is even more obvious: an attitude of not living in ecological balance and self-sufficiency has resulted in an unprecedented rate of species extinction, both plant and animal [29–30]. The so-called 'Anthropocene Epoch' has been so devastating to other biological life on Earth that this era of human dominance has been rightly faulted for "the sixth mass extinction" [31]. Pliny's Stoicism, which recognized that humans can destructively influence nature to the point of making a plant go extinct, was simply the beginning. To this we can add the many

#### *Ancient Greco-Roman Views of Ecology, Sustainability, and Extinction: Aristotle, Stoicism… DOI: http://dx.doi.org/10.5772/intechopen.104989*

ways that, as Stoics predicted, the Earth has responded with violence to both itself ("the world being shaken") and humanity ("destruction"): anthropogenic climate change and hazardous pollution are the two most ready examples that come to mind, to say nothing of the warlike destruction our species visits upon itself with historical regularity.

Modern ecological thinking has attempted to redress our relationship with the natural world in a manner strikingly similar to ancient Stoicism, by re-thinking nature and our place in it in metaphysical and religious terms. In ancient Stoicism, Seneca described a view of nature that emplaces humanity within the framework of religious humility, as he is baffled by humanity's narrow-mindedness around our place within nature while being simultaneously in awe of nature and its grand operations. These two operate side by side:

*"I myself give thanks to nature whenever I see her, not in her public aspect, but when I have entered her more remote regions, when I am learning what the material of the universe is, who is its creator or guardian, what God is, whether he is totally focused on himself or sometimes takes notice of us too, whether he creates something every day or has created once and for all, whether he is part of the world or the world itself, whether even today he may make decisions and amend part of the law of fate, or whether it would be an impairment of his greatness and an admission of error to have made something that needed alteration." (1.3) [28]*

Seneca continues, framing the issue truly as a matter of good and evil, extending the religious view of ecology in the previous quote:

*"[The mind] has consummated and fulfilled the blessings of human destiny only when it had trampled over every evil and has sought the heights and entered the inner recesses of nature. Then, as it wanders among the stars themselves, it takes delight in laughing at the paved floors of the wealthy and at the whole Earth with its gold – I refer not just to what it has disgorged and given to the mint for stamping into coinage, but also to what it keeps hidden for the greed of posterity." (1.7.8) [28]*

Humans have moved far beyond nourishment and, in Stoic terms, have acted nonvirtuously, extracting not out of necessity but out of greed. This is all fundamentally baffling, for our desires and wants and wars are miniscule in a metaphysical view that blends nature with god:

*"The mind cannot despise colonnades, and ceilings gleaming with ivory, and topiary forests and rivers channeled into houses until it has toured the entire world and until, looking down from on high at the Earth – tiny, predominantly covered by sea, and, even when it rises above it, mainly uncultivated, and either burnt or frozen – it has said to itself, 'this is that pinprick that is carved up among so many nations by sword and fire?'" (1.7.8) [28]*

Such views are striking, not only in their poetry but in their similarity to modern ecological writings, especially those with a more religious, spiritual, or new-age bent. The origins of modern environmentalism and ecology can be rightly traced to the work of Alexander von Humboldt (1769–1859), the famous naturalist, explorer, and polymath whose influence in the world of nature science was so colossal and unparalleled it is difficult to overstate [32].

Among Humboldt's many scientific contributions, one of his most lasting was the view of nature as a unified whole governed by inter-relationships, personified in his magnum opus *Kosmos* where he argued for the interrelationship of not only all of biological nature but all of science and humanity too [32]. As far as historical influence, Humboldt's views and writing importantly gave rise to Charles Darwin's (1809–1882) own views on evolution and speciation, who in turn has become much better remembered than Humboldt himself. But Humboldt's work was one of only two that Darwin brought on his famous voyage on the *Beagle* to the Galapagos Islands and beyond, and Darwin's writings engage extensively with Humboldt, whom he admired greatly [32].

In a fascinating parallel to the two poles of ecological thinking we found in ancient Stoicism, we see a similar dynamic playing out in the work of Humboldt and Darwin around their views of nature. Scientifically, Humboldt and Darwin are rightly understood as part of a single intellectual lineage, for they both understood nature as acting upon and within itself, and as both highlighting the importance of understanding nature holistically in terms of the inter-relationship of all its parts, ranging from climate to population dynamics to the dynamism of natural change.

But there is a core difference between the two in terms of how they understood nature's holism [33]. Humboldt took the much broader view, that nature can and should be understood holistically, that ecology in the large was to be understood as a single organism functioning in harmonious equilibrium. By contrast, Darwin focused on the notion of competition (so-called 'survival of the fittest'), that nature was teeming with violence and the struggle for resources. In the words of Stephen Jay Gould, there are (at least) three fundamental "aspects of the new Darwinian world. All confute central aspects of Humboldt's vision" [33]. First, Darwin believed that "Nature is a scene of competition and struggle, not higher harmony" as Humboldt believed [33]. Second, also contra Humboldt, Darwin argued that "Evolutionary lineages have no intrinsic direction toward higher states or greater unification. Natural selection is only a process of local adaptation" [33]. And third, Darwin concluded that "Evolutionary changes are not propelled by an internal and harmonious force", which departed strikingly from Humboldt's own conclusions [33].

Darwin understood nature locally and brutally, with a series of random, weighted events propelling survival and speciation outcomes. Humboldt saw nature broadly and beautifully, with a sort of divine order and harmonious outcome of balance. Of course, both are true biologically, as it is simply a matter of scale: at the micro level of individual organisms and species you see savage and unrelenting violence and competition; at the macro level of an entire ecosystem, however, one sees harmony, balance, and beauty. It merely depends on one's own metaphysical view of where to locate the truth of nature.

Humboldt was himself not religious. Indeed, he does not mention God once in his magnum opus *Kosmos*, which described the entirety of the universe at both macroscopic and microscopic scale [34]. But his more spiritual perspective on nature is strikingly similar to the non-deistic view of 'nature as god' propounded by the Stoics, who frequently used the term 'god' in their writings but not in the sense of the personlike, agential deities found in Greco-Roman mythology. In both Humboldt and Stoic thinking, nature operates broadly and harmoniously and provides propitiously for all biological organisms. To pick up our argument from our analysis of the ancient sources, Humboldt's view is closer to the second pole of Stoic ecological thought, which focused on balance and harmony and humanity's ability to destroy and disrupt nature. Indeed, Humboldt's works were innovative and influential in speaking to the

*Ancient Greco-Roman Views of Ecology, Sustainability, and Extinction: Aristotle, Stoicism… DOI: http://dx.doi.org/10.5772/intechopen.104989*

deleterious human effects on nature, in some of our first theorization around species loss and climate change [32].

Humboldt's more spiritual perspective on nature therefore lent itself to later ecological thinking along these lines. He was particularly influential, for instance, on the scientific (and sometimes even religious) views of later ecologists in the West. This includes both more historically proximate writers such as Henry David Thoreau (1817–1862, a founder of modern naturalism) and Ralph Waldo Emerson (1803–1882, leader of transcendentalism), but also later preservationists such as John Muir (1838–1914, the key driver for the founding of the National Parks System in the United States, which in turn became a model for the global West) and Rachel Carson, whose 1962 book *Silent Spring* in many ways birthed the modern ecological conservation movement [32].

Humboldt's view also gave rise to analogical thinking in the humanistic and political sphere. He thought, for example, that because all of nature was unified and beautiful in its diversity, that such principles extended to human culture as well. He was therefore a strong proponent of cultural and racial equality, arguing loudly and across his entire life against slavery and in favor of equal rights to those oppressed by the European colonial empires [32]. For Humboldt, colonialism and theories of racial hierarchy were environmentally destructive too [32], showing the fundamental linkages between all of nature, not just plants and animals but humanity and human systems of politics too.

By contrast, Darwin's view – of competition, violence, and hierarchy – well parallels the first pole of Stoic ecological thinking, that such principles are natural and normal in nature. The founders of modern naturalism and ecology, in other words, continued to struggle with the same tension we see in Stoicism. And while Humboldt made no mention of God in *Kosmos*, Darwin's ecology more explicitly engaged with the notion:

*"To my mind, it [nature's perfection] accords better with what we know of the laws impressed on matter by the Creator, that the production and extinction of the past and present inhabitants of the world should have been due to* secondary causes*, like those determining the birth and death of the individual." (383) [35]*

In the words of a modern interpreter of Darwin, "Darwin invokes the "Creator," but leaves him out of the work of life and death … The Creator may impress his laws on matter, but the laws of matter are all that are revealed by the phenomena Darwin investigates" (xxv) [35]. Like Humboldt, Darwin's thought includes the "absence of divine intention" (xxv) [35], but while Humboldt is comfortable excluding deism entirely, Darwin is still willing to engage with the notion of a Creator. Humboldt's religious views seemed to abstract away entirely from a creator god in terms of his ecological metaphysics; Darwin seemed to allow for a creator god but, in a manner strikingly similar to our second pole of Stoic thought, Darwin believed that divinity could be found in the metaphysical and scientific principles of nature while things like extinction were due to "secondary causes" such as human influence.

Darwin's thought, meanwhile, gave rise to a very different kind of humanistic and political thinking from Humboldt's. While Darwin himself was no racist or bigot and indeed was explicitly anti-slavery [36–37], the notion of 'Social Darwinism' was later derived from his thought [38]. This idea – that hierarchy is natural and normal and thus such principles should also apply to human society – was used for decades in an attempt to justify slavery, racial hierarchy, and colonialism. Just as with Humboldt, we see that one's metaphysical views of nature are extended into the world of politics and culture too. One might well favor Darwin's biological perspective, and indeed there is a reason that we remember his name more than Humboldt's when it comes to his theories of nature and its operations, but Humboldt's more spiritualist view of metaphysical unity certainly leads to a more sustainable, holistic, and equitable view of human diversity.

We can now return to the idea that began our paper, extinction, and the role of scientific and religious thinking in its understanding. Our modern understanding of extinction stems from the work of Georges Cuvier (1769–1832), a contemporary of Humboldt whose scientific ideas cohere in some ways with the shared Humboldtian and Darwinian ecological frameworks. In Cuvier's *Essay on the Theory of the Earth* (1813), he set out with the simple objective to determine the identities of organisms found in the fossil record [39]. Cuvier came to a bold conclusion: some of the fossilized animal remains found below the surface of the Earth were so unlike existing species that they must have gone *extinct*. Such a conclusion was controversial in his time. Other naturalists, such as Jean-Baptiste Lamarck (1744–1829), believed that species could not go extinct, but rather adapted to their environments throughout their lifetimes, ultimately passing on those newly acquired traits to their offspring [40–41]. In this view, such fossils merely represented earlier versions of still-existing species, making extinction an impossibility.

Cuvier took the opposite view, arguing in favor of extinction and firmly opposing the idea of species adaptation:

*"Why may not the presently existing races of land quadrupeds, it has been asked, be modifications of those ancient races which we find in a fossil state; which modifications may have been produced by local circumstances and change of climate; and carried to the extreme difference which they now present, during a long succession of ages? This objection must appear strong to those especially who believe in the possibility of indefinite alteration of forms in organized bodies; and who think that, during a succession of ages, and by repeated changes of habitudes, all the species might be changed into one another, or might result from a single species. Yet to these persons an answer may be given from their own system. If the species have changed by degrees, we ought to find traces of these gradual modifications. Thus, between the palaeotheria and our present species, we should be able to discover some intermediate forms; and yet no such discovery has ever been made." [42]*

Here, Cuvier proposed a revolutionary idea for his time: animal remains found in the fossil record offered clear evidence for species extinction. Yet in the same stubborn breath, he perhaps made the biggest blunder of his academic career by dismissing Lamarck's idea that species could adapt to changing environments. In hindsight, we know that neither Lamarck nor Cuvier were entirely correct, but each of them had made an important contribution to the broader understanding of life on Earth.

Cuvier believed that all species were perfectly adapted to their environments and as a result, any significant change of those environments could threaten their very existence. This idea aligns closely with the Humboldtian view of nature's harmonious balance of interrelated species, each of which occupies a unique ecological niche to the benefit of the larger whole. However, Cuvier did not always see nature as beautiful, but rather as a brutal system plagued by shocking changes, intense competition, and occasional catastrophes. This view – which parallels Seneca's previous assertion that disturbing the balance of nature would result in its destruction – influenced Darwin's

*Ancient Greco-Roman Views of Ecology, Sustainability, and Extinction: Aristotle, Stoicism… DOI: http://dx.doi.org/10.5772/intechopen.104989*

own ideas about competition, ecological change, and extinction. Extinction, according to Darwin, only occurs when a species is unable to adapt to their changing environment.

Cuvier's outright dismissal of species adaptation was in effect an intellectual roadblock, preventing him from capturing the whole picture of natural selection. In doing so, he also left open the major question of how species are created, lending credence to the ancient ideas of spontaneous generation and godly creation. Indeed, Cuvier's own stance was widely used by creationists and those seeing divine design in nature [43], a position that has persisted in small and non-scientific areas of thinking today.

### **6. Conclusion: the metaphysics of ecology**

In this chapter, we have surveyed key strands of thought in the western tradition, both ancient and modern, around the relationship between religion, science, ecology, and sustainability. In the ancient Mediterranean, the most influential explorations of this relationship include Aristotle and the later Stoic tradition. Our earliest views in ancient Greece saw nature as providential, divine, and therefore not allowing for human-caused extinction such as those of plants or animals. Later Stoic views, in particularly Pliny the Elder, noted the extinction of the famous and valuable plant silphium.

This extinction event illuminates a key difference between ancient Stoic thinkers. While Stoicism generally holds to a metaphysical view of nature as divine, Stoics themselves differentiated on the extent to which humans can and should exploit nature and its resources. We identified two poles of thinking in ancient thought: one pole that followed Aristotle in arguing that nature's divine providence results in hierarchical exploitation being natural and therefore to some extent good; and another pole that departed from Aristotle, especially as articulated by Pliny, in arguing that nature's divine providence results in hierarchical exploitation being unnatural and therefore to some extent bad. This difference results, we think, from the core metaphysical orientations of these two poles, regarding the nature of religion and ecology. The former pole sees sustainability outside the province of humanity, while the latter pole sees sustainability as a crucial element of one's proper religious and philosophical orientation to the universe.

In the later west, we see this same metaphysical intersection, encompassing all of science and philosophy and religion around the subject of ecology, in the pioneering work of Alexander von Humboldt and Charles Darwin. Although aligned in a great many ways, Humboldt and Darwin departed in crucial ways around the nature of ecology. Humboldt's metaphysical views of the cosmos see unity and harmony as fundamental principles, and therefore that human's extractive behaviors are abnormal and morally wrong, going against the very principles of the universe. It is for this reason that Humboldt's thought had an outsize effect on later syntheses of ecology, philosophy, religion, and sustainability, ranging from transcendentalism to modern eco-spiritualists. Such lines of thought in Humboldt and subsequent thinkers in his lineage well parallel the second pole of Stoic thinking, as found in Pliny but also in others such as Seneca and Epictetus, that views humanity as potentially destructive of nature's natural and divine harmony. In this view, extinction is unnatural and fundamentally bad; humanity's influence has resulted in a host of deleterious extinctions.

Darwin, by contrast, viewed competition and struggle as fundamental principles of nature. While Darwin did not pursue the humanistic social and political implications of his thought as Humboldt did, this metaphysical stance was appropriated by later

thinkers who believed that the hierarchy and violence found in natural were natural and therefore good, using this stance to justify deplorable political, economic, and social systems. In this way, *mutatis mutandis*, such lines of Darwinian thought parallel the other pole of Stoic thinking, as found in the notorious imperialist Marcus Aurelius as well as the earlier Aristotle and his view of 'natural slavery' (*Politics* 1254b16–23) [44], that views humanity as deserving of nature's bounty and that lower order beings of all kinds are naturally suited to be used by others. In this view, extinction is natural and not necessarily bad; indeed, extinctions and major extinction events have occurred long before the influence of humans.

An attention to both ancient and modern thought helps us today to illuminate the relationship between science, philosophy, and religion around the subjects of sustainability and ecology. Influential voices in history have essentially argued in favor of the hierarchical exploitation of nature and non-sustainable ecological practices. However, other important voices have identified sustainability as a crucial dimension of our ideal religious and metaphysical stance. The issue of species extinction in particular highlights how thinkers, both ancient and modern, explore the relationship between sustainability, ecology, religion, and philosophy. A goal of ecological sustainability is not only metaphysically possible within the history of western scientific and religious thinking, but also justified by thinkers ranging from Pliny the Elder to Alexander von Humboldt and beyond.
