Griechische Wissenschaft Zeitlinie

About 450 or later
Proclus (Πρόκλος ο Λύκιος) the final head of Plato's Academy, said that astronomers "do not arrive at conclusions by starting from hypotheses, as is done in the the other sciences; rather, taking conclusions [the appearance of the heavens] as their point of departure, they strive to construct hypotheses from which effects conformable to the original conclusions follow with necessity" (Proclus, quoted by Duhem 1908:20). The astronomer is only interested in saving the appearance of the phenomena, and whether this conforms to reality is left to the other sciences to decide.

About 500
Metrodorus (Μητρόδωρος ο Χίος) assembles the Greek Anthology consisting of 46 mathematical problems.

517
John Philoponus determined that falling objects do so with the same acceleration, or 'impetus,' specifically opposing Aristotle's notion that the air through which a projectile moved was its motive force.

After 520
Ancius Manlius Severinus Boethius wrote De consolatione philosophiae in Latin, probably the most widely read book in Europe in the Middle Ages, and translated Aristotle's logical books. "Until the rediscovery of Aristotle in the twelfth century his translations were the basic texts for all students of logic" (Park 1990:79). He also wrote a commentary on Porphyry's logic. Aside from Boethius and Augustine, students in the monasteries read Pliny's first century Historia Naturalis, Cassiodorus's sixth century encyclopedia, Isadore of Seville's sixth century Etymolagiarum, and Discorides' De Materia Medica.

About 530
Simplicius of Cilicia, in a commentary in Greek on Aristotle's writings on 'gravity', interpreted him to mean that the intensity of the tendency of bodies toward their natural place varied with their distance from that place.

About 800
Jabir ibn Hayyan, later known as Geber, was educated reading translations from Greek and based his chemical system "on two substances: sulphur, which...is hot and dry, and mercury, which is cold and wet. Since each contains all four elements, any other material can be formed by the proper combination of these two, and since we cannot know substance but only form, our search must aim at the most desired product, gold" (Park 1990:115). This is the most perfect, most virtuous product since, as Aristotle said, all things, even base metals, struggle upward.

About 850

Abu Yusek Yacob ibn Ishak al-Kindi commented on Aristotle and wrote numerous treatises on optics, perspective, and medicine.

About 900
Abu Bakr al-Razi, better known as Rhazes, distinguished smallpox from measles in the course of writing several medical books in Arabic. Holding against any sort of orthodoxy, particularly Aristotle's physics, he maintained "the conception of an 'absolute' time, regarded by him as a never-ending flow" (Pines 1975:125).

About 1000

Ibn Sina, or Avicenna, hypothesized two causes of mountains: "Either they are the effects of upheavals of the crust of the earth, such as might occur during a violent earthquake, or they are the effect of water, which, cutting itself a new route, has denuded the valleys, the strata being of different kinds, some soft, some hard.... It would require a long period of time for all such changes to be accomplished, during which the mountains themselves might be somewhat diminished in size" (Toulmin and Goodfield 1965:64). In Kitah al-Shifa, he denied the Aristotelian notion that an object thrown through the air is pushed by that air and held that "every motion occurs through a power in the moving object by which it is impelled" (Avicenna, quoted in Pines 1975:141). He also published Al-Quanun, or Canon of Medicine, where he held that medicines were to be known either by experiment or by reasoning.

About 1000

Ibn al-Haitham, or al-Hazen, in Opticae Thesaurus, introduced the idea that light rays emanate in straight lines in all directions from every point on a luminous surface. He also discussed spherical and parabolic mirrors and was aware of spherical aberration. In Epitome of Astronomy, he took a position against Ptolemy, insisting that the hypothetical spheres corresponded "to the true movements of really existing hard or yielding bodies [and] so...were accountable to the laws of physics" (Duhem 1908:28). This led to disagreements that persisted through the twelfth century.

About 1126

Adelard of Bath translated Euclid's Elements and al-Kwarizmi's arithmetic and astronomical tables from Arabic into Latin.

After about 1150
Ibn Rushd, better known in Latin Europe as Averroës, and also sometimes as the Commentator, wrote commentaries on several of Aristotle's books where he explained that prime matter, matter at its most fundamental level, has no form of its own. Its essence is its potential. He also criticized the artificiality of Ptolemy's orbits: "Astronomers propose the existence of these orbits as if they were principles and then deduce conclusions from them" (Averroës, quoted by Duhem 1908:30).

1175
Gerard of Cremona had translated from Arabic into Latin most of Aristotle's work as well as Ptolemy's Almagest, Autolycus of Pitane's De spera mota, Avicenna's Canon, al-Kindi's treatise on optics, and some of Rhazes' medical books.

About 1185
Burgundio of Pisa translated from Greek into Latin various treatises by Galen and Aphorisms by Hippocrates of Cos.

About 1190
Moses ben Maimon, better known as Maimonides, wrote The Guide for the Perplexed in Arabic for Arabic-speaking Jews and included his ideas about astrological systems. For sublunar physics, he accepted the word of Aristotle as wholly true: This is man's sphere. But the heavens are the 'deity's,' and therefore man cannot know them, but can only try to describe them "rely[ing] on the arrangement postulating the lesser number of motions" (Maimonides 1963:274), reiterating Ptolemy and Proclus.

1206
al-Jazari published a book in which he demonstrated some understanding of the use of a crank for producing reciprocal rotary motion. "No secure evidence evidence for it is found in Europe earlier than c. 1405" (White 1962:111). The crank had been understood at least as early as Archimedes, but presumably forgotten in the Dark Ages.

About 1215
Robert Grosseteste "made the first thorough logical analysis of the inductive and experimental procedures of practical science" (Crombie 1953:35). He called for investigation of effects leading to discovery of causes followed by demonstration of how causes produce effects, i.e., resolutio and compositio, Aristotle's double movement. But since this only provided a possible cause, at the end of compositio, a process of experimental verification and logical falsification is required. Grosseteste considered light to be the basis of all natural causes so he considered optics the basis of all explanation: He not only attempted mathematical explanations of the properties of mirrors and lenses, rainbows and refraction, but also to explain the rectilinear propagation of light as a succession of waves. "He was the first medieval writer to discuss these subjects systematically" (Crombie 1953:116). He also translated from Greek into Latin part of Simplicius' commentary on Aristotle's De Caelo et Mundo.

1217
Michael Scot translated into Latin Averroës' commentaries on Aristotle as well as some texts of Aristotle's. Probably later, he gave the University of Salerno recipe for anesthesia as equal parts opium, mandragora, and henbane. He also wrote a treatise ascribing to each of the practical sciences a corresponding theoretical science of which it is the manifestation.

About 1230
Vincent of Beauvais compiled about six thousand folio pages in an encyclopedia, Speculum majus, of knowledge gleaned from translations of Greek and Arabic books on philosophy, science, and mathematics.

[Throughout the Middle Ages there were various schools of thought about the Aristotelian system of the universe. Among the Franciscans at Oxford, there were two schools. Most accepted only some explanations of natural phenomena such as the movement of heavenly bodies. Others, such as Roger Bacon, were less offended by pagan metaphysics and had great interest in Aristotelian medicine, physics, and mathematics. At the University of Paris, there were also two schools. Dominicans, such as Albertus Magnus and Thomas Aquinas, accepted most Aristotelian principles, except for determinism. The other school of thought, represented by Siger de Brabant, accepted an entirely deterministic interpretation of the universe. At Montpellier in the south of France and at the Italian universities, Salerno, Padua, and Bologna, theological matters counted for less and Aristotle and the Arabs were studied mainly for medical learning (Crombie 1952:41).]

About 1250
Albert of Bollstadt, called Albertus Magnus, in De Vegeabilibus et Plantis, a commentary on a pseudo-Aristotelian plant book, shows "a sense of morphology and ecology unsurpassed from Aristotle and Theophrastus to [Andrea] Cesalpino" (Crombie 1952:204). Probably following this, Albertus wrote De Animalibus, a commentary on three treatises of Aristotle as well as commentaries on Avicenna's Canon and some of Galen's works.

About 1260
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