Exploring Aristotle's philosophical method and the merits of his conclusions, Irwin here shows how Aristotle defends dialectic against the objection that it cannot justify a metaphysical realist's claims. He focuses particularly on Aristotle's metaphysics, epistemology, philosophy of mind, and ethics, stressing the connections between doctrines that are often discussed separately.

Ptolemy presents only one argument for the eccentricity in his models of the superior planets, while each one of them has two eccentricities: one for center of the uniform motion, the other for the center of the constant distance. To take into account the first eccentricity, he introduces the equant point, but he provides no argument for the eccentricity of the center of the deferent. Why is the second eccentricity different from the first one? The 13 th century astronomer Quṭb (...) al-Dīn al-Shīrāzī, a member of the famous school of Marāgha, who was interested in this problem, suggests the “retrograde arcs” as the empirical origin of the second eccentricity and develops an argument to justify this conjecture. Although his argument is not without difficulty, his suggestion is in line with the suggestions made by some historians of astronomy in recent decades. Résumé Ptolémée ne donne qu'un seul argument pour expliquer dans son système l'excentricité des planètes supérieures, alors que chacune d'elles a deux excentricités: l'une par rapport au centre du mouvement uniforme, l'autre par rapport au centre de la distance constante. Pour rendre compte de la première excentricité, il introduit le point équant, mais il ne donne en revanche aucun argument pour l'excentricité par rapport au centre du cercle déférent. Or, pourquoi la seconde excentricité est-elle différente de la première? Quṭb al-Dīn al-Shīrāzī, astronome du xiii e siècle membre de l'école de Marāgha, qui s'est intéressé à cette question, a fait l'hypothèse que les “arcs de rétrogradation” constituent l'origine empirique de cette seconde excentricité. Bien que l'argument sur lequel il appuie cette hypothèse ne soit pas exempt de difficultés, sa suggestion rejoint celles faites par des historiens de l'astronomie durant les dernières décennies. (shrink)

The book contends that the digression ending Simplicius’ In de caelo 2.12 is not a proper history of early Greek planetary theory, but a creative atempt to show that to accept Ptolemy’s planetary hypotheses one need not repudiate Aristotle’s argument that the cosmos is eternal.

: In earlier work, Bernard R. Goldstein and the present author have introduced a procedural rule for historical inquiry, which requires that one take pains to establish the credibility of any citation of ancient thought by later writers in antiquity through a process of verification. In this paper, I shall apply what I call the Rule of Ancient Citations to Simplicius' interpretation of Aristotle's remarks in Meta L. 8, which is the primary point of departure for the modern understanding of (...) Greek planetary theory. I first sketch several lines of argument that lead me to conclude that Simplicius' interpretation should not be accepted because it assumes a concern with planetary phenomena unknown to the Greeks before the late 2nd and early 1st centuries BC. Then, after showing that there is a fairly well defined range of readings of Aristotle's remarks more in keeping with what we actually know of astronomy in the 5th and 4th centuries BC, I conclude that neither Aristotle's report about the Eudoxan and Callippan accounts of the celestial motions nor Simplicius' interpretation of this report is a good starting point for our understanding of early Greek planetary theory. (shrink)

The undoubted truth is that there exist for the planetary motions true and constant configurations from which no impossibilities or contradictions follow; they are not the same as the configurations asserted by Ptolemy; and Ptolemy neither grasped them nor did his understanding get to imagine what they truly are.

‘Saving the appearances’, , is a slogan that, in its time, stood or was made to stand for many different methodological positions in many different branches of ancient natural science. It is not my aim, in this paper, to attempt to tackle the subject as a whole. I shall concentrate on just one inquiry, astronomy. Nor, with astronomy, can I do justice to all the complexities of what was certainly one of the central methodological issues, if not the central issue, (...) in the history of ancient theoretical astronomy. I have a quite limited aim, to examine the foundations, and test the applicability, of a widespread and influential line of interpretation of ancient Greek astronomy according to which it was essentially, or at least predominantly, what we may call ‘instrumentalist’ in character—that is, broadly speaking, that Greek astronomical theories were devices or fictions put forward purely for the sake of calculations with no claims to correspond with physical reality. (shrink)

Bringing the meta-mathematics of Hero of Alexandria and Claudius Ptolemy into conversation for the first time, I argue that they employ identical rhetorical strategies in the introductions to Hero’s Belopoeica, Pneumatica, Metrica and Ptolemy’s Almagest. They each adopt a paradigmatic argument, in which they criticize the discourses of philosophers and declare epistemological supremacy for mathematics by asserting that geometrical demonstration is indisputable. The rarity of this claim—in conjunction with the paradigmatic argument—indicates that Hero and Ptolemy participated in a single meta-mathematical (...) tradition, which made available to them rhetoric designed to introduce, justify, and bolster the value of mathematics. (shrink)

‘Saving the appearances’,, is a slogan that, in its time, stood or was made to stand for many different methodological positions in many different branches of ancient natural science. It is not my aim, in this paper, to attempt to tackle the subject as a whole. I shall concentrate on just one inquiry, astronomy. Nor, with astronomy, can I do justice to all the complexities of what was certainly one of the central methodological issues, if not the central issue, in (...) the history of ancient theoretical astronomy. I have a quite limited aim, to examine the foundations, and test the applicability, of a widespread and influential line of interpretation of ancient Greek astronomy according to which it was essentially, or at least predominantly, what we may call ‘instrumentalist’ in character—that is, broadly speaking, that Greek astronomical theories were devices or fictions put forward purely for the sake of calculations with no claims to correspond with physical reality. (shrink)

The novel understanding of the physical world that characterized the Scientific Revolution depended on a fundamental shift in the way its protagonists understood and described space. At the beginning of the seventeenth century, spatial phenomena were described in relation to a presupposed central point; by its end, space had become a centerless void in which phenomena could only be described by reference to arbitrary orientations. David Marshall Miller examines both the historical and philosophical aspects of this far-reaching development, including the (...) rejection of the idea of heavenly spheres, the advent of rectilinear inertia, and the theoretical contributions of Copernicus, Gilbert, Kepler, Galileo, Descartes, and Newton. His rich study shows clearly how the centered Aristotelian cosmos became the oriented Newtonian universe, and will be of great interest to students and scholars of the history and philosophy of science. (shrink)