**2. Ancient Greco-Roman views of religion, science, ecology, and extinction: Plato, Aristotle, and Theophrastus**

In many ancient Greek and Roman traditions, it was believed that the natural world was created to provide for humankind. Humanity, as a higher-order lifeform, had natural dominion over all other organisms (e.g. plants and animals) and was thus fully warranted to utilize its authority for personal gain. As early as Homer's *Odyssey* (8th century BCE), Odysseus' encounter with the Cyclops Polyphemus sets up a clear contrast between civilized Greeks who cultivate and sow the Earth and the barbaric or inhuman Cyclopes who live in a state of wild, uncultivated nature [1–3]. Odysseus, in this view, was justified in his exploitation of the Cyclops and the violence done to him. Nature was not something peaceful to be respected but rather something to be conquered and used.

Ancient philosophical and scientific views reflected this same attitude regarding the hierarchical relationship of humanity to nature, starting with Plato (5th century BCE). Plato's tripartite view of the self – reason, spirit, and appetite – held that while humanity shared its appetitive characteristics with other organisms such as animals, humanity was distinguished by its unique possession of reason which allowed the soul

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

to ascend to a higher contemplative state [4]. Aristotle (4th century BCE) followed his teacher in emplacing humanity at the top of the creaturely hierarchy, and progressed even further by discussing in greater detail the relationship between humanity and nature. Underpinned by Plato's ontological foundations, Aristotle's view of the hierarchical relationship of humanity and/over nature became dominant and largely persisted in the western world – with exceptions, discussed below – until the European Renaissance.

Aristotle follows Plato by asserting that humanity is superior to nature on the basis of our rational character, which is not shared by other animals, much less plants or natural objects [5–7]. Aristotle understands this hierarchy teleologically, where everything in nature exists for a function – a notion that underpins many of his other scientific views too. This results in the conclusion that nature, and all of its many constituent parts lacking rationality, are subservient to rational humanity [8]. Aristotle famously and explicitly articulated this view in the *Politics*:

*"In like manner we may infer that, after the birth of animals, plants exist for their sake, and that the other animals exist for the sake of man, the tame for use and food, the wild, if not all at least the greater part of them, for food, and for the provision of clothing and various instruments. Now if nature makes nothing incomplete, and nothing in vain, the inference must be that she has made all animals for the sake of man." [9]*

This view, of what is ultimately a divine and providential understanding of nature undergirded by an anthropocentric metaphysics, is widely present in both Peripatetic and Middle/Late Stoic thought (3rd century BCE – 3rd century CE). We will see many parallels in our treatment of Stoicism below.

Aristotle was aware of the fact that ecological exploitation could result in the decline of a wild species' population, but also held the belief that the creation of life happens spontaneously and continuously, in a manner irrespective of human conduct [10]. In *On the Generation of Animals* (*De Generatione Animalium*, henceforth *GA*), Aristotle posited that the creation of an organism could occur by means of sexual reproduction but also due to spontaneous generation (*GA* 759a-b, 762a), a climactic process of admixture between rain and matter which we also see in Lucretius and Pausanias [11, 12]. This chthonic, spontaneous generation is present in a variety of species, for example, the fish that he discusses in *History of Animals* (*HA*) (*HA* 569a, 548a; cf. *HA* 539b). Such views were extended by later thinkers to a whole host of organisms, ranging from amphibians to mammals [13, 14].

Aristotle extends his naturalistic theories to metaphysics, as "the explanation of animal generation also has metaphysical importance for him … the generation of an entity must be explicable within that system" [15]. For Aristotle, all generation – spontaneous and not – depended not only on localized conditions (which might conceivably be influenced by humans) but more fundamentally on the metaphysical conditions of the cosmos more broadly, namely "the activity of the heavenly bodies upon the *pneuma* and the material" [15]. Humans, of course, affect the natural world, but the productive capacity of the natural world is an inevitable product of larger forces beyond the sphere of human influence. Aristotle's view explains why the notion of extinction was largely foreign to him, for it violated the notion that humanity could have a permanently destructive effect on the environment or any single given species.

Theophrastus (4th-3rd century BCE), successor to Aristotle, articulated this view well: he claimed that the silphium plant came into existence as a result of

"spontaneous generation" after a black rain of a "heavy, pitchy" nature blanketed the region of Cyrenaica (present-day northeastern Libya) in the 7th century BCE [16]. Here, Theophrastus mirrors the broadly providential view of nature that Aristotle held: the loss of any one plant or animal species was only temporary and humanity's influence on the environment marginal. After all, any species whose population had been diminished by human activity could spontaneously reappear at any moment. Extinction in the modern, permanent sense of the word was simply impossible according to Aristotle's (dominant and highly influential) scientific and metaphysical views.

### **3. Pliny the elder: a new voice in ecology**

One figure stands apart from this Aristotelian strand of thought: Pliny the Elder. Pliny (23–74 CE) was a highly distinguished member of ancient Roman society. Over his life he held important military positions and was closely connected with the political elite, for example a direct friendship with Vespasian [17]. He was also prolific in his literary output, which included not only historical works but also extensive work in the natural sciences [18]. Most notable in the latter was his *Natural History* (*Naturalis Historia*), a sprawling and encyclopedic work with huge swaths of material in the natural sciences including geography and botany.

Pliny's work contains many prior influences from Aristotle and subsequent philosophical traditions [19]. In fact, his *Natural History* is full of references to both the idea of spontaneous generation by nature and the notion of nature being hierarchical and therefore of use to humanity. On the latter, in a typical example, he writes that "[Nature] pours forth a profusion of medicinal plants, and is always producing something for the use of man." (1.2.63) [14].

Pliny also follows Aristotle in the importance granted to the spontaneously generative power of wind and rain. He variously describes reports of matter falling from the sky, ranging from the mundane (stones; tiles) to the alarming (milk; blood). While the former might be explained away by the wind taking up material objects, the latter is not explained but merely highlighted as a given (1.2.38, 57) [14]. Pliny even notes the generation of plants in this manner, reiterating Theophrastus' account of silphium's appearance as an example (3.16.61) [14]. He concludes broadly that "All these productions owe their origin to rain, and by rain is silphium produced", right in line with Aristotle (4.22.48) [14]. However, in nearly every such instance, Pliny provides details such as the location and date, perhaps to suggest that he himself is skeptical and that the reader should go confirm the occurrence of these events for themselves.

Importantly, Pliny expands this conclusion with a claim that notably departs from the prevailing ecological theory of his predecessors: "As already observed, the silphium of Cyrenae no longer exists" (4.22.48) [14]. Indeed, it is in *Natural History* that we find, for the first time in ancient western history, an explicit engagement with the notion of extinction as a permanent ecological phenomenon, with regard to the ancient herb silphium [20]. Noting a variety of the distinct geographic, botanical, and cultural factors at work, Pliny comes to the novel conclusion that the actions of humanity directly resulted in the extinction of a species and that this result is irreversible; recent research has argued that human-caused climate change was the principal factor in silphium's extinction [21].

This conclusion begs a series of questions around ancient ecology and religion. If Pliny believed that the natural world providentially furnished things for humanity,

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

what would it mean that one could no longer exist? How could the extinction of a species be permanent if that same species were the product of natural forces such as wind and rain? If humanity has little power over these divine and natural forces, how could we even force something to go extinct if we tried?

We argue that the key to answering these questions can be found in Pliny's metaphysics, in particular at the intersection of religion and ecology. This intersection reflects a particular brand of Stoic thinking that highlights a fundamental tension in Stoic thought around the role of humanity and its relationship to a divinely understood nature.

Pliny's metaphysics take influence from both Aristotelian and prior Stoic views (among others) that there is a power beyond humanity over which we have little control. Pliny clearly conceives of nature in the classic Stoic sense as divine, not in a deistic sense of an agential and person-like god, but rather in a broader and more abstract sense of the divine. He asserts that the "world, and whatever that be which we otherwise call the heavens … we must conceive to be a deity, to be eternal, without bounds, neither created, nor subject, at any time, to destruction." (1.2.1) [14] As such, he asserts that "it is ridiculous to suppose that the great head of all things, whatever it be, pays any regard to human affairs" (1.2.5) [14]. It is clear that nature, in the sense of ecology, is understood as itself a divine force: "the power of nature is clearly proved and is shown to be what we call god" (1.2.5) [14]. In this paradigm, nature cares little for humans because we are merely small creatures living within the grand operations of the cosmos; therefore nothing we do can truly influence nature. Such a line of thought largely underpins Aristotelian and some Stoic views, leading to the notion that it is not possible for human actions to cause the extinction of a species.

Pliny, however, comes to a different conclusion. Although he clearly understands nature as a divinity, he does not view nature as an agential and a person-like god. Nature, therefore, cannot operate according to whims, desires, and intentions; in other words, not like the gods classically understood in Greek mythology. Rather, the divinity of nature operates according to universal principles, such as those of science:

*"[God cannot] make mortals immortal, or recall to life those who are dead; nor can he effect, that he who has once lived shall not have lived, or that he who has enjoyed honours shall not have enjoyed them; nor has he any influence over past events but to cause them to be forgotten. And, if we illustrate the nature of our connection with god by a less serious argument, he cannot make twice ten not to be twenty, and many other things of this kind." (1.2.5) [14]*

Nature, as with god, cannot bring somebody back to life or change the past or any number of other things. Nature is limited by nature's own inherent operations.

This point helps explain Pliny's earlier comments around humanity's inability to create, destroy or otherwise alter the natural world. When Pliny states that humanity cannot affect nature (which is framed as a god), he is asserting that humanity cannot change the fundamental workings (e.g. natural operations; universal laws) of the universe. These not only include the known processes of the natural world (e.g. gravity, geology, reproduction, chemical and biological change, etc.) but also the unfounded natural processes which Pliny believed to have existed (e.g. spontaneous generation of organisms and material objects). In stating this, Pliny is *not* asserting that humanity cannot influence the manifestation of nature on Earth. So while humans cannot change the inherent ability of two animals to reproduce, for example, they might capture, injure, or kill the animals and thereby thwart the manifestation of this biological process. While humans cannot change the properties of water such that it turns to steam at high temperatures and freezes at low temperatures, humans can surely remove or add heat to water to prevent or facilitate these changes in a given situation. The causes and operations of nature/god remain beyond the bounds of humanity, but not the effects and manifestations. To briefly look ahead, Charles Darwin himself settles on such a view too.

Pliny's differentiation (causes/operations vs. effects/manifestations) is crucial, as it allows him to take a wider view on the deleterious effects of human actions on the natural world. In poetic language strikingly similar to modern ecological writing, Pliny takes a dark view of humanity's ecological behaviors:

*"[Nature] is continually tortured for her iron, her timber, stone, fire, corn and is even much more subservient to our luxuries than to our mere support. What indeed she endures on her surface might be tolerated, but we penetrate also into her bowels, digging out the veins of gold and silver, and the ores of copper and lead; we also search for gems and certain small pebbles, driving our trenches to a great depth. We tear out her entrails in order to extract gems with which we may load our fingers ... And truly we wonder that this same Earth should have produced anything noxious!" (1.2.63) [14]*

Nature is readily anthropomorphized, in a prototypical blend of religion and ecology, as Pliny notes that the natural ecological balance theorized by prior thinkers was about meeting natural needs. By contrast, humanity's avarice for "luxuries" beyond "mere support" leads to nature being "continually tortured", being penetrated for mineral extraction, and having her entrails torn out sheerly for the sake of human decoration.

Along similar lines, Pliny affords nature some broad agency, using the extractive relationship of humanity and nature to explain why the "Earth should have produced anything noxious". Humanity, it seems, has upset the divine and natural order, with resulting consequences. In another strong echo of modern ecological writing, Pliny then continues to say that all of this exploitation of the natural world would result in disastrous consequences for humanity, "inasmuch as all this wealth ends in crimes, slaughter, and war" (1.2.63) [14]. By upsetting the divine and natural order, in the end we are only hurting ourselves. And nature – well, she will exist long after we are gone: "while we drench her with our blood, we cover her with our unburied bones; and being covered with these … her anger being thus appeased" (1.2.63) [14]. Nature is both divinely anthropomorphized and understood as unified with the human condition; in doing the Earth wrong we do ourselves wrong as we are part of nature; and ultimately this is all understood not only in a clear scientific context of cause and effect between the natural and human worlds but also in the urgent terms of a sincerely held religious view of our place in the cosmos.
