The Division of the World
Miller, James B., The World and I
The dualistic modern worldview undergirding Western culture's intellectual mainstream and undermining its Judeo-Christian heritage traces its roots to the science of Copernicus, Galileo, and Newton and the philosophy of Descartes and Kant.
The birth of modern culture is often understood to coincide with that of modern science, as commonly identified with the publication in 1543 of On the Revolutions of Celestial Bodies by Nicolaus Copernicus (1473- -1543). The book was not a scientific work in the modern sense, however. It was instead a philosophically motivated mathematical argument against the prevailing Aristotelian/Ptolemaic cosmology. It was grounded in Copernicus' commitment to a Platonic and Pythagorean philosophical perspective.
Beginning with a set of cosmological and metaphysical presuppositions drawn from Aristotle (e.g., the perfection of the heavens and circular motion as the perfect form of motion), Ptolemy (c. 87--150 c.e.) had developed an Earth-centered system of cosmic geometry that described the observed motions of the heavenly bodies. To make his geometric system match observations, he found it necessary to include an element of irregular motion that compromised the heavenly movements' perfection.
Copernicus found this philosophical flaw especially troublesome and showed that it could be overcome by assuming that the Sun, not Earth, was at the center of the cosmic motions. Copernicus inherited his heliocentricism from the Pythagoreans, who, as early as the fourth century c.e., had proposed a twofold motion of Earth: rotation about an axis and revolution about the Sun. Thus Copernicus proposed no radically new position but rather recovered an ancient view that had been lost amid the dominance of Aristotelian thought.
Copernicus' moves against the presuppositions of his day involved both the geometry of heavenly movements and the presumed truth of mathematical astronomy. For most of his contemporaries, mathematics as applied to the motions of the heavens served strictly practical purposes. It was valuable as an aid to astrological calculations or for establishing the dates of civil and religious events, but it was not seen as a reflection of the "true" cosmic order.
Faith in mathematics
In his preface to On the Revolutions of Celestial Bodies, addressed to Pope Paul III, Copernicus described his position as "almost against common sense." Ordinary experience seemed to show that the Earth was stationary and that the Sun revolved around it. Yet, Copernicus argued that the demands of mathematics in service to metaphysical assumptions about the perfection of heavenly motion required that what was empirically obvious was not true. He thus elevated mathematics as a source of knowledge above metaphysics, the traditional interpretation of Scripture, and even ordinary sense experience.
This commitment to a mathematically "ideal" description of the world was shared by Galileo Galilei (1564--1642). In the mythos of modern culture, Galileo is the champion of Copernicanism who fell victim to dogmatic religious repression. But this is too simple a characterization.
Galileo's trial was the outcome of a complex set of factors, which included his own aggressive personality and the charged atmosphere over religious and cultural authority that marked the Reformation. In this context, Galileo's challenge to Aristotle's intellectual authority in the area of astronomical cosmology and terrestrial physics threatened papal authority because Aristotle was the implicit philosophical authority within late medieval Christian theology.
Galileo's terrestrial physics depended on the acceptance of what Stephen Toulmin has called "ideals of natural order." For example, Galileo asserted the principle of "frictionless" motion as a presupposition for his mathematical description of the pendulum or falling bodies. He never observed such ideal motion. Yet, this theoretical ideal was a foundation for Galileo's physics and shows his Pythagorean/Platonic commitment to identify reality with the purity of ideal mathematical form. …