Gerard of Cremona is a good example: an Italian who traveled to Spain to copy a single text, he stayed on to translate some seventy works. His biography describes how he came to Toledo: "He was trained from childhood at centers of philosophical study and had come to a knowledge of all that was known to the Latins; but for love of the Almagest, which he could not find at all among the Latins, he went to Toledo; there, seeing the abundance of books in Arabic on every subject and regretting the poverty of the Latins in these things, he learned the Arabic language, in order to be able to translate."
The rediscovery of the works of Aristotle allowed the full development of the new Christian philosophy and the method of scholasticism. By 1200 there were reasonably accurate Latin translations of the main works of Aristotle, Euclid, Ptolemy, Archimedes, and Galen—that is, of all the intellectually crucial ancient authors except Plato. Also, many of the medieval Arabic and Jewish key texts, such as the main works of Avicenna, Averroes and Maimonides now became available in Latin. During the 13th century, scholastics expanded the natural philosophy of these texts by commentaries (associated with teaching in the universities) and independent treatises. Notable among these were the works of Robert Grosseteste, Roger Bacon, John of Sacrobosco, Albertus Magnus, and Duns Scotus.
Scholastics believed in empiricism and supporting Roman Catholic doctrines through secular study, reason, and logic. The most famous was Thomas Aquinas (later declared a "Doctor of the Church"), who led the move away from the Platonic and Augustinian and towards Aristotelianism (although natural philosophy was not his main concern). Meanwhile, precursors of the modern scientific method can be seen already in Grosseteste's emphasis on mathematics as a way to understand nature and in the empirical approach admired by Roger Bacon.
Under the tuition of Grosseteste and inspired by the writings of Arab alchemists who had preserved and built upon Aristotle's portrait of induction, Bacon described a repeating cycle of observation, hypothesis, experimentation, and the need for independent verification. He recorded the manner in which he conducted his experiments in precise detail so that others could reproduce and independently test his results - a cornerstone of the scientific method, and a continuation of the work of researchers like Al Battani.
Bacon and Grosseteste conducted investigations into optics, although much of it was similar to what was being done at the time by Arab scholars. Bacon did make a major contribution to the development of science in medieval Europe by writing to the Pope to encourage the study of natural science in university courses and compiling several volumes recording the state of scientific knowledge in many fields at the time. He described the possible construction of a telescope, but there is no strong evidence of his having made one.
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—essence of "The Law of Falling Bodies" -- long before Galileo is credited with 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."
Renaissance of the 15th century
Main article: History of science in the Renaissance
The 15th century saw the beginning of the cultural movement of the Renaissance. The rediscovery of Greek scientific texts, both ancient and medieval, was accelerated as the Byzantine Empire fell to the Ottoman Turks and many Byzantine scholars sought refuge in the West, particularly Italy. Also, the invention of printing was to have great effect on European society: the facilitated dissemination of the printed word democratized learning and allowed a faster propagation of new ideas.
When the Renaissance moved to Northern Europe that science would be revived, by figures as Copernicus, Francis Bacon, and Descartes (though Descartes is often described as an early Enlightenment thinker, rather than a late Renaissance one).
Byzantine and Islamic influences
Main articles: Byzantine science and Science in medieval Islam
Byzantine science played an important role in the transmission of classical knowledge to the Islamic world and to Renaissance Italy, and also in the transmission of medieval Arabic knowledge to Renaissance Italy. Its rich historiographical tradition preserved ancient knowledge upon which splendid art, architecture, literature and technological achievements were built.