But to pursue this remarkable line of thinking from Plato to Kepler, we must first briefly attempt to reconstruct the ancient view of the heavens prior to Plato, specifically that associated with the earliest astronomer-astrologers from the ancient Mesopotamian kingdom of Babylonia. For it was from these distant origins nearly two millennia before Christ that the cosmology of the West would first emerge.
It would appear that from very early times ancient observers noticed a fundamental distinction between the celestial and terrestrial realms. While earthly life was everywhere marked by change, unpredictability, generation and decay, the heavens seemed to possess an eternal regularity and luminous beauty that established them as a realm of an entirely different and superior order. While observations of the heavens continued to disclose this unchanging regularity and incorruptibility night after night, century after century, observations of mundane existence by contrast revealed incessant change—with plants and animals, the seas and the weather undergoing ceaseless alteration, with human beings dying and being born, with entire civilizations rising and passing away. The heavens appeared to possess an order of time that transcended human time, an order of time suggestive of eternity itself. It was also evident that the movements of the heavenly bodies influenced earthly existence in various ways—bringing dawn after every night, for example, or spring after every winter, with unfailing constancy. Certain major seasonal fluctuations in climatic conditions, droughts, floods, and tides seemed to coincide with specific phenomena in the heavens. And while the heavens appeared as a vast distant space beyond human reach, populated by insubstantial, jewel-like points of bright light, the earthly environment was immediate, tangible, and composed of patently grosser materials like rock and dirt. The celestial realm seemed to express—indeed it seemed to be—the very image of transcendence. Perhaps because the heavens were distinguished by these extraordinary qualities—luminous appearance, timeless order, transcendent location, terrestrial effects, and an all-encompassing majesty—the ancients viewed the celestial realm as the residence of the gods. The starry sky reigned above as an eternal revolving illustration of the mythic deities, their visible incarnation. From this perspective, the heavens were not so much-a metaphor for the divine, but rather the divine’s very embodiment.
The divine character of the heavens compelled human attention to the patterns and movements of the stars, with significant events in the celestial realm considered indicative of parallel events in terrestrial life. In the imperial cities of ancient Babylonia, centuries of continuous and increasingly precise observations, for omens as well as for calendrical calculations, gave rise to a large body of systematic astronomical records. But when these observations, as well as their mythological correspondences, reached the cultural environment of the early Greek philosophers, and there met the Hellenic demand for coherent rational and natural explanation, a fundamentally new dimension in cosmological speculation was created. While for other contemporary cultures the heavens remained, like the overall world view, principally a mythological phenomenon, for the Greeks the heavens became linked as well to geometrical constructions and physical explanations, which in turn became basic components of their evolving cosmology. The Greeks thereby bestowed to the West a tradition which demanded that a cosmology not only must satisfy the human need to exist in a meaningful universe—a need already served by the archaic mythological systems—but must also delineate a coherent physical and mathematical structure of the universe accounting for detailed systematic observations of the heavens.8
In accord with their newly naturalistic outlook, early Greek philosophers such as the Ionians and the atomists began regarding the heavens as composed of various material substances whose movements were mechanically determined. But the evidence that the celestial motions maintained a consistent order in perfect conformity to mathematical patterns was for many Greeks a fact pregnant with significance. For Plato in particular, that mathematical order revealed the heavens as the visible expression of the divine Reason and the embodiment of the anima mundi, the living soul of the universe. In his cosmological dialogue, the Timaeus, Plato described the stars and planets as visible images of immortal deities whose perfectly regulated movements were paradigms of the transcendent order. God, the primordial artist and craftsman (Demiurge) who had formed the world from a chaos of primordial matter, had created the heavens as a moving image of eternity, revolving precisely according to perfect mathematical Ideas, which in turn created and established the patterns of time. Plato believed it was man’s encounter with the celestial movements that had first given rise to human reasoning about the nature of things, to the divisions of the day and the year, to numbers and mathematics, and even to philosophy itself, that most liberating of the gods’ gifts to mankind. The universe was the living manifestation of divine Reason, and nowhere was that Reason more fully manifest than in the heavens. If earlier philosophers had thought the latter comprised nothing more than material objects in space, for Plato their evident mathematical order proved otherwise. Far from being merely a soulless domain of moving stones and dirt, the heavens contained the very sources of the world order.
Plato therefore stressed the value of studying the movements of the heavens, for the harmonious symmetry of the celestial revolutions constituted a spiritual perfection directly accessible to human understanding. By devoting himself to things divine, the philosopher could awaken divinity within himself and bring his own life into intelligent harmony with the celestial order. In the spirit of his Pythagorean forebears, Plato elevated astronomy to high status among those studies demanded in his ideal education for the philosopher-ruler, for astronomy revealed the eternal Forms and divinities governing the cosmos. Only the person who had fully applied himself to such studies, and through his long labor of education comprehended the divine ordering of things both in the heavens and on Earth, could be capable of being the just guardian of a political state. An unthinking traditional belief in the existence of the gods was acceptable for the masses, but a prospective ruler should be expected to have mastered all possible proofs of the universe’s divinity. He must be able to regard the many and perceive the one, the divine intelligent unity of design behind all apparent diversity. The paradigmatic field for this philosophical imperative was astronomy, for above all the passing phenomena of the world stood the timeless perfection of the heavens, whose manifest intelligence could inform the philosopher’s life and awaken wisdom in his soul.
Beginning with Thales (renowned for having predicted an eclipse) and Pythagoras (credited with being the first to conclude that the Earth was a sphere, rather than a flat circular disc as in Homer and Hesiod), each of the major Greek philosophers had brought new insights concerning the apparent structure and character of the cosmos. By Plato’s time, the continuing observations of the heavens had revealed a cosmos that seemed to most thoughtful observers to be structured in two concentric spheres, with the vast outer sphere of stars revolving diurnally westward around the much smaller sphere of the Earth, and with the Earth stationary in the exact center of the universe. The Sun, Moon, and planets revolved in approximate synchrony with the outer starry sphere, moving in a space somewhere between the Earth and the stars. The conceptual clarity of this two-sphere scheme, which readily explained the overall diurnal motion of the heavens, gradually allowed Greek astronomers to discern what Babylonians had earlier observed but what was to the Greeks, with their passion for lucid geometrical understanding, a disturbing phenomenon. Indeed, the phenomenon now fully revealed was so problematic as to challenge the entire science of astronomy and to place the divine scheme of the heavens in jeopardy. For it had become evident that several celestial bodies did not move with the same eternal regularity as did the rest, but instead they “wandered” (the Greek root for the word “planet,” planētēs, meant “wanderer,” and signified the Sun and Moon as well as the other five visible planets—Mercury, Venus, Mars, Jupiter, and Saturn). Not only did the Sun (in the course of a year) and th
e Moon (in a month) move gradually eastward across the starry sphere in an opposite direction from the westward diurnal movement of the entire heavens. More puzzling, the other five planets had glaringly inconsistent cycles in which they completed those eastward orbits, periodically appearing to speed up or slow down relative to the fixed stars, and sometimes to stop altogether and reverse direction while emitting varying degrees of brightness. The planets were inexplicably defying the perfect symmetry and circular uniformity of the heavenly motions.
Because of his equation of divinity with order, of intelligence and soul with perfect mathematical regularity, the paradox of the planetary movements seems to have been felt most acutely by Plato, who first articulated the problem and gave directions for its solution. To Plato, the proof of divinity in the universe was of the utmost importance, for only with such certainty could human ethical and political activity have a firm foundation. In the Laws, he cited two reasons for belief in divinity—his theory of the soul (that all being and motion is caused by soul, which is immortal and superior to the physical things it animates), and his conception of the heavens as divine bodies governed by a supreme intelligence and world soul. The planetary irregularities and multiple wanderings seemingly contradicted that perfect divine order, thereby endangering human faith in the divinity of the universe. Therein lay the significance of the problem. Part of the religious bulwark of Platonic philosophy was at stake. Indeed, Plato considered it blasphemous to call any celestial bodies “wanderers.”
But Plato not only isolated the problem and defined its significance. He also advanced, with remarkable confidence, a specific—and in the long run extremely fruitful—hypothesis: namely, that the planets, in apparent contradiction to the empirical evidence, actually move in single uniform orbits of perfect regularity. Although there would seem to have been little but Plato’s faith in mathematics and the heavens’ divinity that could have supported such a belief, he enjoined future philosophers to grapple with the planetary data and find “what are the uniform and ordered movements by the assumption of which the apparent movements of the planets can be accounted for”—i.e., to discover the ideal mathematical forms that would resolve the empirical discrepancies and reveal the true motions.9 Astronomy and mathematics were to be mastered in order to penetrate the riddle of the heavens and comprehend their divine intelligence. Naive empiricism, which took the appearance of erratic and multiple planetary movements at face value, was to be overcome by critical mathematical reasoning, thereby revealing the simple, uniform, and transcendent essence of the celestial motions. The philosopher’s task was to “save the phenomena”—to redeem the apparent disorder of the empirical heavens through theoretical insight and the power of mathematics.
Of course, “saving the phenomena” was in some sense the main goal of all Platonic philosophy: to discover the eternal behind the temporal, to know the truth hidden within the apparent, to glimpse the absolute Ideas that reign supreme behind and within the flux of the empirical world. But here Plato’s philosophy was put on the line, so to speak, in open confrontation with a specific empirical problem under the full gaze of future generations. The problem itself was significant only because of the Greeks’, and particularly Plato’s, assumptions about geometry and divinity—that the two were intrinsically associated with each other and with the heavens. But the long-term consequences of those assumptions—consequences that would develop directly from the centuries-long struggle with the planetary movements—were to be singularly antithetical to their Platonic foundation.
Here, then, we find many of the most characteristic elements of Platonic philosophy: the search for and belief in the absolute and unitary over the relative and diverse, the divinization of order and the rejection of disorder, the tension between empirical observation and ideal Forms, the consequently ambivalent attitude toward empiricism as something to be employed only to be overcome, the juxtaposition of the primordial mythic deities with the mathematical and rational Forms, the further juxtaposition of the many gods (the celestial deities) with the single God (the Creator and supreme Intelligence), the religious significance of scientific research, and finally the complex and even antithetical consequences which Plato’s thought would hold for later developments in Western culture.
Before moving onward past Plato, let us briefly review the various methods for acquiring knowledge suggested in the course of the Platonic dialogues. Knowledge of the transcendent Ideas that were the governing principles of the divine intelligence was the foundation of Platonic philosophy, and access to this archetypal knowledge was said to be mediated by several different (and usually overlapping) cognitive modes, involving different degrees of experiential directness. The Ideas could be known most directly through an intuitive leap of immediate apprehension, which was also considered to be a recollection of the immortal soul’s prior knowledge. The logical necessity of the Ideas could also be discovered by meticulous intellectual analysis of the world of empirical experience, both through dialectic and through mathematics. In addition, the transcendent reality could be encountered through the astronomical contemplation and understanding of the heavens, which displayed the moving geometry of the visible gods. The transcendent could also be approached through myth and the poetic imagination, as well as by attending to a kind of aesthetic resonance within the psyche touched off by the presence of the archetypal in veiled form within the phenomenal world. Thus intuition, memory, aesthetics, imagination, logic, mathematics, and empirical observation each played a specific role in Plato’s epistemology, as did spiritual desire and moral virtue. But of all these, the empirical was typically depreciated and, at least in its uncritical employment, considered more hindrance than help in the philosophical enterprise. This was the legacy that Plato passed on to his most brilliant pupil, Aristotle, who studied for twenty years in Plato’s Academy before setting forth his own distinctive philosophy.
Aristotle and the Greek Balance
With Aristotle, Plato was, as it were, brought down to earth. And if, from a Platonic view, the luminosity of Plato’s universe based on the transcendent Ideas was diminished in the process, others would point to a decisive gain in the articulate intelligibility of the world as described by Aristotle, and would indeed consider his outlook to be a necessary modification of Plato’s idealism. To understand the basic tenor of Aristotle’s philosophy and cosmology is prerequisite for comprehending the further movement of Western thought and its succession of world views. For Aristotle provided a language and logic, a foundation and structure, and, not least, a formidably authoritative opponent—first against Platonism and later against the early modern mind—without which the philosophy, theology, and science of the West could not have developed as they did.
The problem of discovering the exact character and development of Aristotle’s thought presents a different set of difficulties from that facing the interpreter of Plato. Virtually none of Aristotle’s extant works were apparently intended for publication. Works that were published by Aristotle are now lost, these being highly Platonic in doctrine and written in popular literary form, while those that survive are concentrated treatises composed for school use in the form of lecture-course notes and texts for students. These surviving manuscripts were compiled, edited, and titled by Aristotelians several centuries after the philosopher’s death. The modern attempt to trace Aristotle’s development from this much-transformed body of material has not brought forth unequivocal results, and his judgments on certain issues remain obscure. Yet the overall character of his philosophy is clear, and a general theory of its evolution can be surmised.
It would seem to be that after an initial period when his thought still reflected a more unreservedly Platonic influence, Aristotle began to construct a philosophical position sharply distinguished from his master’s. The crux of their difference involved the precise nature of the Forms and their relation to the empirical world. Aristotle’s intellectual temperament was one that took the empirical world on its own te
rms as fully real. He could not accept Plato’s conclusion that the basis of reality existed in an entirely transcendent and immaterial realm of ideal entities. True reality, he believed, was the perceptible world of concrete objects, not an imperceptible world of eternal Ideas. The theory of Ideas seemed to him both empirically unverifiable and fraught with logical difficulties.
To counter that theory, Aristotle put forth his doctrine of categories. Things can be said “to be” in many ways. A tall white horse is in one sense “tall,” in another sense “white,” and in another sense a “horse.” Yet these different ways of being are not equivalent in ontological status, for the tallness and whiteness of the horse depend for their existence entirely on the primary reality of the particular horse. The horse is substantial in its reality in a way that the adjectives describing it are not. To distinguish between these different ways of being, Aristotle introduced the notion of categories: the particular horse is a substance, which constitutes one category; its whiteness is a quality, which constitutes another category altogether. The substance is the primary reality, upon which the quality depends for its existence. Among the ten categories established by Aristotle, only substance (“this horse”) signifies concrete independent existence, while the others—quality (“white”), quantity (“tall”), relation (“faster”), and the rest—are derivative ways of being in that they exist solely relative to an individual substance. A substance is ontologically primary, while the various other types of being that may be predicated of it are derivative. Substances underlie and are the subjects of everything else. If substances did not exist, nothing would exist.
For Aristotle, the real world is one of individual substances which are distinct and separate from each other, yet which are characterized by qualities or other types of being held in common with other individual substances. This commonality, however, does not signify the existence of a transcendent Idea from which the common quality is derived. The common quality is a universal recognizable by the intellect in sensible things, but it is not a self-subsistent entity. The universal is conceptually distinguishable from the concrete individual, but is not ontologically independent. It is not itself a substance. Plato had taught that things like “whiteness” and “tallness” possessed an existence independent of any concrete things in which they might appear, but for Aristotle that doctrine was untenable. The error, he held, lay in Plato’s confusion of categories, whereby he treated a quality, for example, as a substance. Many things can be beautiful, but that does not mean there is a transcendent Idea of the Beautiful. Beauty exists only if at some point a concrete substance is beautiful. The individual man Socrates is primary, while his “humanness” or “goodness” exists only to the extent that it is found in the concrete particular Socrates. In contrast to the primary reality of a substance, a quality is only an abstraction—though it is not merely a mental abstraction, for it is based on a real aspect of the substance in which it resides.
Passion of the Western Mind Page 8