Late Middle Ages (AD 1300–1500)
The first half of the 14th century saw the scientific work of great thinkers. The logic studies by William of Occam led him to postulate a specific formulation of the principle of parsimony, known today as Occam's Razor. This principle is one of the main heuristics used by modern science to select between two or more underdetermined theories.
As Western scholars became more aware (and more accepting) of controversial scientific treatises of the Byzantine and Islamic Empires these readings sparked new insights and speculation. The works of the early Byzantine scholar John Philoponus inspired Western scholars such as Jean Buridan to question the received wisdom of Aristotle's mechanics. Buridan developed the theory of impetus which was a step towards the modern concept of inertia. Buridan anticipated Isaac Newton when he wrote:
. . . after leaving the arm of the thrower, the projectile would be moved by an impetus given to it by the thrower and would continue to be moved as long as the impetus remained stronger than the resistance, and would be of infinite duration were it not diminished and corrupted by a contrary force resisting it or by something inclining it to a contrary motion.
Thomas Bradwardine and his partners, the Oxford Calculators of Merton College, Oxford, distinguished kinematics from dynamics, emphasizing kinematics, and investigating instantaneous velocity. They formulated the mean speed theorem: a body moving with constant velocity travels distance and time equal to an accelerated body whose velocity is half the final speed of the accelerated body. They also demonstrated this theorem—the essence of "The Law of Falling Bodies"—long before Galileo, who has gotten the credit for this.
In his turn, Nicole Oresme showed that the reasons proposed by the physics of Aristotle against the movement of the earth were not valid and adduced the argument of simplicity for the theory that the earth moves, and not the heavens. Despite this argument in favor of the Earth's motion Oresme, fell back on the commonly held opinion that "everyone maintains, and I think myself, that the heavens do move and not the earth."
The historian of science Ronald Numbers notes that the modern scientific assumption of methodological naturalism can be also traced back to the work of these medieval thinkers:
- By the late Middle Ages the search for natural causes had come to typify the work of Christian natural philosophers. Although characteristically leaving the door open for the possibility of direct divine intervention, they frequently expressed contempt for soft-minded contemporaries who invoked miracles rather than searching for natural explanations. The University of Paris cleric Jean Buridan (a. 1295-ca. 1358), described as "perhaps the most brilliant arts master of the Middle Ages," contrasted the philosopher’s search for "appropriate natural causes" with the common folk’s erroneous habit of attributing unusual astronomical phenomena to the supernatural. In the fourteenth century the natural philosopher Nicole Oresme (ca. 1320–82), who went on to become a Roman Catholic bishop, admonished that, in discussing various marvels of nature, "there is no reason to take recourse to the heavens, the last refuge of the weak, or demons, or to our glorious God as if He would produce these effects directly, more so than those effects whose causes we believe are well known to us."
However, a series of events that would be known as the Crisis of the Late Middle Ages was under its way. When came the Black Death of 1348, it sealed a sudden end to the previous period of massive scientific change. The plague killed a third of the people in Europe, especially in the crowded conditions of the towns, where the heart of innovations lay. Recurrences of the plague and other disasters caused a continuing decline of population for a century.
Famous quotes containing the words ages, middle and/or late:
“Riches are valuable at all times, and to all men; because they always purchase pleasures, such as men are accustomed to, and desire: Nor can any thing restrain or regulate the love of money, but a sense of honour and virtue; which, if it be not nearly equal at all times, will naturally abound most in ages of knowledge and refinement.”
—David Hume (17111776)
“In middle age, I practiced feeling old, but the real thing has been a rude surprise.”
—Mason Cooley (b. 1927)
“If a liberal policy towards the late Rebels is adopted, the ultra Republicans are opposed to it; if the colored people are honored, the extremists of the other wing cry out against it. I suspect I am right in both cases.”
—Rutherford Birchard Hayes (18221893)