lead in turn to the other major deviation from Plato, namely the considerably less important role of mathematics in Aristotle’s thought. Many of these ideas are illustrated by considering how Aristotle would envision the growth of a plant from its seed. Within the seed lies the inherent purpose of becoming the eventual plant, and the growth of the plant is caused by the need for the seed to fulfill this purpose. The natural motions of the stars in circles or of falling rocks toward the ground or of flames leaping upward illustrate again the same way of thinking. Assigning a causal purpose to the qualitatively observed changes in the world constituted an explanation in the philosophy of Aristotle, and this shaped the concept of nature that he developed. Mathematics is not an effective language for explaining qualitative changes, whereas teleological reasoning was well suited for the verbal and logical methods preferred by Aristotle and for the complicated organic phenomena that he empirically observed in such detail.
Although I have focused attention on the approaches to nature developed by Plato and Aristotle as if these were isolated, in both cases we should bear in mind that the nature philosophies were parts of a broader system of thought that included epistemological, ethical, political, ontological, and religious components. These parts are interconnected, and in particular it’s somewhat artificial to separate the religious aspect from the concept of nature, since the divine Nous provides the animating purpose and the source of harmony and form in nature. The world is in some sense an organic creature with a mind and soul, and this element of their concept of nature is found in a great deal of the Greek thinking both before and after these two philosophers. We’ll return to this point again later. Lastly, in the case of Aristotle, the total collection of work aimed to systematize all knowledge and thought into an overarching synthesis that included nature, humanity, logic, and spirit. Much subsequent work was an elaboration of or a reaction to this corpus.
One strand of development in the Greek view of nature was largely independent of Aristotle’s work, however, and this concerned the role of mathematics. Mathematics itself developed considerably, becoming more creative, rigorous, and systematic in the work of Apollonius, Archimedes, and Euclid. The major application of mathematics to the natural world was in astronomy, owing to the high degree of regularity in the celestial motions and large amount of observational information accumulated. Although the Babylonians had employed sophisticated mathematical algorithms to this problem, the great innovation of the Greeks was to devise what we would call mathematical models, i.e. to devise a theoretical concept of how the sun, moon, and planets must move, work out its mathematical implications, and compare these to the actual motions. From the early work of Eudoxus to the culminating system of Ptolemy, this project dominated astronomy, but the attempts of Aristotle’s followers to give a physical explanation for these basically mathematical pictures gave rise to issues that would survive the end of antiquity. An aspect of the Greek concept of nature was forming that did not quite cohere effectively.
The work of Archimedes in statics and hydraulics was a rigorous application of mathematics to natural phenomena. Such work was a more modern-looking and less mystical version of the old Pythagorean concept. Although the investigations of Archimedes were brilliant successes, they were too isolated to greatly affect the general Greek concepts of nature (though they did sow the seeds of much later science). Archimedes also performed some practical engineering work, and the practice of engineering and applied science (metal working, agriculture, etc.) in general formed another aspect of the Greek approach to the world in late antiquity. The most famous practitioners in this tradition were Vitruvius and Hero of Alexandria (the latter best known for his small steam-driven device). Yet another practical tradition that continued to make progress in improving knowledge of the world was found in medicine, including the knowledge of human anatomy discovered by dissection. But the knowledge resulting from these kinds of practical pursuits, though important, was not incorporated into any larger vision or theoretical structure. Such knowledge must have influenced the Greek view of nature indirectly, but it remained fragmentary and isolated, not really contributing to a new coherent concept of nature.
This latter project remained the province of philosophy, either that of Plato and Aristotle (and their commentators) or that of three new rival schools that arose: Epicureanism, Stoicism, and Neoplatonism. None of these philosophies, however, regarded understanding the world as their highest priority. Epicureanism and Stoicism were both primarily ethical philosophies, concerned with the right way to live; both devised concepts of nature as a means toward the end of promoting virtue and equanimity in their followers. Neoplatonism was primarily a mystical philosophy with the aim of transcending the material world altogether, and thus did not put much effort into nature philosophy, although some Neoplatonists explored further the idea of mathematics as a more fundamental reality underlying physical nature itself. The Epicureans and the Stoics did put forth substantial views of nature, and these views were almost completely different from each other. Epicurus was a materialist and an atomist in the tradition of Democritus. The major innovation of his system was the introduction of chance (“swerve” in the paths of the atoms) in contrast to the totally deterministic (reason and necessity) system of Democritus. The motivation of Epicurus in adding an element of chance to atomism was to allow free will and therefore moral responsibility to the system. The Stoics, whose views varied somewhat with different teachers and times, adopted the old idea that a void could not exist; all space was filled by their two continuous and intermixing substances, an inert material substrate and an animating vital spirit (pneuma) that gives form in accordance with reason. In the Stoic conception, the universe with its pneuma is a living being, of which the human with its soul is a microcosm. The pneuma is corporeal, and in that sense Stoicism is also materialistic even though forms arise through the action of an Intellect, unlike the Epicurean idea of only blind forces acting.
Nature in Chinese Thought
Although Chinese thinking about nature was not entirely static, it was remarkably stable over a period of two thousand years. In traditional Chinese culture, the elements of philosophy, religion, science, social structure, and political order were highly integrated, so looking at their concept of nature in an isolated way is not sensible. Another complication is the somewhat varying influences of Confucianism, Taoism, and Buddhism on their attitudes toward nature. Yet another complication is the presence of occasional voices and movements that lie outside the main current of cultural thought in China, such as the naturalistic tendency found in the Mohist movement or the skeptical writings of Wang Ch’ung. We can present here only a brief and simplified description of the major trends in Chinese thought concerning nature.
One of the primary cornerstones of Chinese thinking is that it is correlative rather than causal when considering the relationships between events, things, ideas, etc. There are connections between things (north and feminine, for example) that are not either causal or logical relations but rather these connections are said to exist inherently in the make-up of the universe; such correlations are simply a part of the way things are, not the result of anything acting on the things or mutual actions of the things on each other. One major consequence of this correlative thinking is the importance of microcosm/macrocosm interpretations of nature. “A basic feature of systematic thought about the external world as it arose in China is that the body and the state were miniature versions (not just models) of the cosmos.”19 In this view, the human is a microcosm of the entire universe, the macrocosm, and there are a host of correlations between the two. Human society, identified with the state, is also a microcosm of the macrocosmic world. These three realms (human, society, cosmos) are linked together by many particular correspondences and also linked together by the person of the Emperor, who must perform the correct rituals to maintain order in the cosmos and in the society. Beyond its political implications, the microcosm/macrocosm view influenced the understanding of natural phenomena. Various organs and parts of the body are associated with parts of the greater world and their processes and functions operate in the same manner. Just as stagnant water gives rise to stench and decay in a pool, so stagnation of the body’s vital fluids leads to illness in a person. The emphasis is much more on process than on structure (anatomy in the body, physical characteristics in the world). “…organs and tissues figured in medical doctrines as mere correlates of the body’s systems of functions, mainly useful in diagnosis and in schemata that aligned parts of the body with
