Environment

Within Western culture, materialist conceptions of the environment do not seem to take shape until the sixth century B.C.E. by the philosophers of the school of Miletus (in Asia Minor). From Thales (625?–?547 B.C.E.) to Anaximander (610–c. 547 B.C.E.) to Anaximenes (fl. c. 545 B.C.E.), these thinkers proposed to reduce the multiplicity of the world to its primary substance or archê (principle): water (in the case of Thales), air (Anaximenes), and an undetermined, eternal substance (apeiron) containing all contraries (Anaximander). It was Aristotle (384–322 B.C.E.) who fully transformed the environment into an object of study by introducing the concept of matter (ulê), which made it possible to conceptualize physical processes (from generation to transformation and movement). Significantly, the period from the sixth to the fourth centuries B.C.E. saw the first systematic inventories of all components of the world: physical geography with Anaximander and Hecataeus (sixth–fifth century B.C.E.) also from Miletus; human geography with Herodotus (c. 484–c. 420 B.C.E.); astronomy with Thales and Eudoxus of Cnidus (c. 400–c. 350 B.C.E.); zoology with Aristotle and his Historia animalium (Research on animals); botany and geology with Theophrastus (c. 372–c. 287 B.C.E.) in the Historia plantarum (Research on plants) and De lapidibus (On stones), respectively.

A fundamental question was the interaction between environment and humans, particularly health issues. The Hippocratic treatise Airs, Waters, Places, probably by the same author as On Sacred Disease (second half of the fifth century B.C.E.), is a study of the implications of environment on human health. The wealth of data provided in the work suggests that the idea was not new at the time, and indeed probably had a long history. The discussion centers on diseases and medicines (especially those made from plants). Diseases were attributed to two different, but possibly complementary, causes: internal disturbances (imbalance of the bodily components) and external effects of the environment. The latter was especially implicated in cases of contagious disease—epidemics, in the current meaning of the word—provoked by some corruption of the air, specifically material particles (the miasmata). As for medicines, their action was explained according to two systems, which perhaps developed chronologically: first, a physical immaterial property (heat or cold, for instance) was understood to be transmitted from the medicinal matter to the body. This system implicitly underpins the most important treatise on medicines of antiquity, De materia medica by the Greek Dioscorides (first century C.E.). Whatever its nature, such a property was conceived as a material element transmitted from the medicinal plant—for example, to the body—in a way that recalls an archaic conceptualization wherein an immaterial element is transmitted from environment to humans. The nature of the property to be introduced into the body was determined by the nature of the disease, and was intended to compensate for a deficiency according to the principle of allotherapy (contraria contrariis). In this way, the environment allowed a return to the natural state of the body.

In a more abstract and probably successive phase, the action of medicines (including plants) was conceived as an exchange of atoms (considered as small indivisible particles, not the atoms of contemporary science). Such a system, which was rooted in atomistic thinking and its medical application, so-called methodism (first century B.C.E.), was best represented by the Greek physician Galen (129–after 216 C.E.). Although more elaborated (since it could account for a wider range of properties), such explanation relied at the end on the same idea as the previous—that is, an exchange between environment and human physiology—with the idea of reestablishing the natural equilibrium of the body. Dioscorides's system, which was most probably not devised by him but utilized anterior knowledge, included a classification of environmental materials ranked so as to form a hierarchy from positively connoted elements to their opposite, with a gradual loss of qualities according to the principle of entropy. Such a classification reflected the history of the world as narrated in the account of the four ages of humankind. According to ancient tales, humankind passed through four ages (from gold to silver, bronze, and eventually iron), each of which corresponded to a degradation of humans' environment and living conditions. Iron era, the present one, is characterized by work, sufferance, and death. Evolution was seen as regressive, not dynamic as in nineteenth-century Darwinian theory, where evolution proceeds by adaptation to changing circumstances and, consecutively, by selection.