This work describes the main basic concepts of the astrological work of Ptolemy, through an analysis of his Tetrabiblos. Comparing his ideas to those of other authors of his time, it is shown that Ptolemy does not present stoic influences, as claimed by some historians. The conclusion of the article is that the basis of Ptolemy's astrology was Aristotle's physics.

In this article, I demonstrate that, of the two horoscopes transmitted by the Anonymous Commentary on Ptolemy’s ‘Tetrabiblos’, edited by Hieronymous Wolf, Basel, 1559, pp. 98 and 112, the first (H1) corresponds to an actual birth that took place in Lower Egypt on 25 June 448 AD, while the second (H2) is the same horoscope, slightly modified to fit the specific example for which it provides the illustration. The new date proposed here for H1 is important for establishing a (...) more precise chronology of the Anonymous Commentary, since it not only provides a terminus post quem for its composition (from the middle of the fifth century onwards) but also a particular geographical environment in the proximity of Alexandria. Given the large amount of formal and structural similarities which can be readily observed between the Anonymous Commentary and commentaries on Plato and Aristotle composed by Ammonius and his disciples in Alexandria, it becomes impossible not to link the work of the anonymous commentator to the Neoplatonic school of Alexandria of the fifth and sixth centuries, led by the philosopher Ammonius and his brother Heliodorus. (shrink)

This analysis of Ptolemy's Teatriblos deals with how the social and cultural role of astrology changed between lì and III century a D.: from a practice hard fought, although successful, to a generally accepted branch of knowledge. In Ptolemy's treatise astrology is shown to be not a science but an art: a techne" fallible but not controvertible. As the basis for such a project of reforming common opinion about astrol¬ogy, we find a quiet yielding attitude toward sceptical antidogmatism, and a (...) non-deterministic way of conceiving man 's naturai relationship with heavenly bodies. (shrink)

The author examines the question of Galen's affinity with astrology, in view of Galen's extended astrological discussion in the De diebus decretoriis . The critical passages from Galen are examined, and shown to be superficial in understanding. The author performs a lexical sounding of Galen's corpus, using key terms with astrological valences drawn from the Critical Days, and assesses their absence in Galen's other works. He compares Galen's astrology with the astrology of Ptolemy's Tetrabiblos, and evaluates their respective strategies (...) of scientific reasoning. Three types of inference are introduced and applied to Galen's astrology. Finally, he concludes that the empirical side of Galen's science does not depend upon astrological methods or concepts, but that these were introduced for their rhetorical effect in presenting his new medical methodology. It is suggested that continued attention to Galen's astrology has obscured the truly important empirical scientific method that Galen developed. (shrink)

The paper presents three strong arguments advocating for the exclusion of the table of Ptolemy’s own planetary terms from the original text of the Tetrabiblos. This table was vastly used by Renaissance astrologers, and much work on its rationale and its manuscript variant readings has been published recently. The author argues that the table was the product of the systematic analysis of Ptolemy’s instructions for the terms in the late antique commentary on the Tetrabiblos edited by Wolf in (...) 1559, and that it entered the direct transmission of Ptolemy’s text in the Byzantine period, probably in the 11th century through cod. Laur. 28,34. The absence of the table in the original Tetrabiblos would explain Ptolemy’s recourse to a probably invented manuscript find and his limited account of the system’s workings. (shrink)

Analisi critica d'opera, incentrata sulla recezione dell'opera di Tolomeo durante il Medioevo e sul pensiero scientifico-filosofico dell' Età Medievale e Rinascimentale.

By the end of the seventeenth century, high culture had banished astrology as a mixture of superstition and imposture. The great astrological treatises of the past - in particular the Ptolemaic Tetrabiblos (whose very authenticity was cast into doubt) - stopped being published; a hodgepodge of minor writings, mostly preserved in manuscript form, lay mouldering in oblivion in the far recesses of libraries. It was only in the latter decades of the eighteenth century that the learned world began once (...) again to pay attention to the ancient art, when historians of ancient religions and science began to realize the impossibility of exploring their subjects without taking into account a presence that could be neither denied nor underestimated. The history of astrology then began to take shape as a specific field of study, and historicophilological research was able to employ it as a tool for penetrating the tie between mythos and logos, at the origin of western civilization. Along with the image of the Greek miracle, an overly simplistic and schematic definition of reason and science began to decline. It was necessary to isolate, as Hermann Usener sought to do, the “wild germ of science” and to acknowledge the fact that logic and magic bloom on the same stem, as Aby Warburg has often reminded us, with reference to Jean Paul. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Before Science: The Invention of the Friars’ Natural Philosophy by Roger French, Andrew CunninghamIrven M. ResnickRoger French and Andrew Cunningham. Before Science: The Invention of the Friars’ Natural Philosophy. Hants, UK: Scolar Press, 1996. Pp. x + 298. Cloth, $68.95.This is a peculiar book that depicts thirteenth-century natural philosophy as wholly dependent on the theological interests of the mendicant orders. For the Friars, “Natural philosophy was a study (...) in which the central concerns were the detection, admiration and appreciation of God’s existence, goodness, providence, munificence, forethought and provision for His creation” (4). Although conceived as “a positive contribution to the discipline of the history of science” (3), the work begins and ends with the claim that medieval natural philosophers were not engaged in science.One difficulty is that the authors never make clear what they mean by science, although they evidently understand that it entails a repudiation of metaphysics and a doctrine of nature’s radical autonomy. Consequently, for French and Cunningham medieval “science” is a mythic construct of modern historians, since “[t]here was no scientific tradition (in the modern sense of the term ‘scientific’) of looking at nature in the thirteenth century, only a religio-political way of doing so” (273).Thus, when summarizing the accomplishments of Roger Bacon, they note that “[Bacon] has been credited, along with Grosseteste, with creating early ‘experimental science’. Bacon could not of course have been a ‘scientist’ because he lived in the wrong [End Page 623] age for this” (238). This seemingly casual conclusion is rather stunning not only in its own right, but also as a revelation of the authors’ own effort to disenfranchise medieval ‘scientists’ for having had the misfortune of living too soon.French and Cunningham propose that polemical or apologetical interests urged the Friars to study nature as a response to various heretics and especially the Cathars who, seemingly like moderns, sought to disengage the natural world from the Christian God, while using the vocabulary of Aristotle’s libri naturales. However this central argument demands better support. Since the authors can cite only one surviving Cathar text—De duobus principiis (ca. 1230)—almost everything known of this group is derived from anti-Cathar polemics. Based on this single text the authors can say no more than that it used “what looks very much like a commentary on Aristotle’s Physics or Metaphysics,” (134) but fail to identify more precisely its sources. It is clear that thirteenth-century orthodox polemics increasingly relied on Aristotelian materials, but the conclusion that natural philosophers did so only in response to heretics who beat them to the Aristotelian punch seems tendentious. The historian will likely remain unconvinced that the unparalleled translating activity of the late eleventh and twelfth centuries—the rendering into Latin of Arabic scientific knowledge (as in Constantine the African’s Pantegni or Adelard of Bath’s Quaestiones naturales), Greek medical literature (e.g. Galen’s Methodus medendi translated by Gerard of Cremona and Burgundio of Pisa) and mathematics (e.g. Euclid’s Optics, Theodosius’s Spherics, Archimedes’ On the Quadrature of the Circle, and Ptolemy’s Tetrabiblos and Almagest) culminating with thirteenth-century translations of Aristotle’s biological works—should all have stemmed from a preoccupation with heresy.A further shortcoming of this book is the limited attention given to works on natural philosophy by the Friars themselves. The book’s first seven of eleven chapters explore the educational establishments in which natural philosophy arose: first monastic and cathedral schools, and then the universities. The works of individual Friars receive only the briefest summary. Among the Dominican natural philosophers Albertus Magnus—the patron saint of scientists and one of a very few scholastics to have commented on all of Aristotle’s biological works—is awarded only five pages. For his mastery of Aristotle’s libri naturales Albertus has been called “the dominant figure in Latin learning and natural science of the thirteenth century.” (Cf. Lynn Thorndike, History of Magic and Experimental Science [New York: Macmillan, 1929], 2:521) Albertus described not only the natural world but also explored the philosophical foundations for scientific knowledge. Yet curiously French and Cunningham give much more attention... (shrink)

SUMMARY. The works of Alexander of Aphrodisias were written a few decades after the publication of the most successful -astrology hand- book in antiquity, Ptolemy's Tetrabiblos Syntaxis, which attempts to naturalize astrology, i.e. to make it agree with Aristotelian theory of science. A comparison of the doctrines between the Tetrabiblos and some passages of Alexander'p works on fate demostrates a noteworthy con¬vergere of the two scholars, and probably a dependence of the lasi great greek Aristotle's exegete on the (...) theories of Ptolemaic astrology, at least in reference to three points: theory of fate; justification of de- vining as a technical and naturai conjecture about man's fate; ana¬lysis of the stars' influence on the sublunary world in physical and phi¬losophical terms. (shrink)