One of the hardest questions to answer for a (Neo)platonist is to what extent and how the changing and unreliable world of sense perception can itself be an object of scientific knowledge. My dissertation is a study of the answer given to that question by the Neoplatonist Proclus (Athens, 411-485) in his Commentary on Plato’s Timaeus. I present a new explanation of Proclus’ concept of nature and show that philosophy of nature consists of several related subdisciplines matching the ontological stratification (...) of nature. Moreover, I demonstrate that for Proclus philosophy of nature is a science, albeit a hypothetical one, which takes geometry as its methodological paradigm. I also offer an explanation of Proclus’ view of what is later called the mathematization of physics, i.e. the role of the substance of mathematics, as opposed to its method, in explaining the natural world. Finally, I discuss Proclus’ views of the discourse of philosophy of nature and its iconic character. (shrink)

Proclus was one of the last great philosophers of Antiquity. His legacy in the cultural history of the west can hardly be overestimated. This book is the most comprehensive guide to Proclus' life, thought and legacy that is currently available.

This volume collects Late Ancient, Byzantine and Medieval appropriations of Aristotle's Posterior Analytics, addressing the logic of inquiry, concept formation, the question whether metaphysics is a science, and the theory of demonstration.

In this paper I show that Proclus is an adherent of the Classical Model of Science as set out elsewhere in this issue (de Jong and Betti 2008), and that he adjusts certain conditions of the Model to his Neoplatonic epistemology and metaphysics. In order to show this, I develop a case study concerning philosophy of nature, which, despite its unstable subject matter, Proclus considers to be a science. To give this science a firm foundation Proclus distills from Plato’s Timaeus (...) the basic concepts Being and Becoming and a number of basic propositions, among others the quasi-definitions of the basic concepts. He subsequently explains the use of these quasi-definitions, that are actually epistemic guides, in such a way that he obtains a connection between a rational and an empirical approach to the natural world. A crucial task in establishing the connection is performed by the faculty of doxa and by geometrical conversion. The result is that Proclus secures a universal, necessary and known foundation for all of philosophy of nature. (shrink)

This chapter provides an analysis of the often mentioned but rarely explained ‘systematicity’ of Proclus’ version of Neoplatonism, and an introduction into the basics of his metaphysics. Starting from the assumption that any philosophical system stems from the desire for explanations, and that for Platonists this involved bridging the opposition between explanandum and explanans, it formulates a number of ensuing requirements, which lead to the construction of what is generally called a philosophical system. The authors then show how this pans (...) out in Proclus’ metaphysics, specifically the One, causality, and triads. Finally, they address the relevance of all this for human life, and briefly evaluate the downsides of Proclus’ systematicity and what sets him apart from predecessors. (shrink)

Aristotle described the scientific explanation of universal or general facts as deducing them through scientific demonstrations, that is, through syllogisms that met requirements he first formulated of logical validity and explanatoriness. In Chapters 19-23, he adds arguments for the further logical restrictions that scientific demonstrations can neither be indefinitely long nor infinitely extendible through the interposition of new middle terms. Chapters 24-26 argue for the superiority of universal over particular demonstration, of affirmative over negative demonstration, and of direct negative demonstration (...) over demonstration to the impossible. Chapters 27 34 discuss different aspects of sciences and scientific understanding, allowing us to distinguish between sciences, and between scientific understanding and other kinds of cognition, especially opinion. Philoponus' comments on these chapters are interesting especially because of his metaphysical analysis of universal predication and his understanding of the notion of subordinate sciences. We learn from his commentary that Philoponus believed in Platonic Forms as inherent in, and posterior to, the Divine Intellect, but ascribed to Aristotle an interpretation of Plato's Forms as independent substances, prior to the Demiurgic Intellect. A very important notion from Aristotle's Posterior Analytics is that of the 'subordination' of sciences, i.e. the idea that some sciences depend on 'higher' ones for some of their principles. Philoponus goes beyond Aristotle in suggesting a taxonomy of sciences, in which the subordinate science is the same in genus as the superordinate, but different in species. (shrink)

In late antiquity, logic developed into what Ebbesen calls the LAS, the Late Ancient Standard. This paper discusses the Neoplatonic use of LAS, as informed by epistemological and metaphysical concerns. It demonstrates this through an analysis of the late ancient debate about hypothetical and categorical logic as manifest in the practice of syllogizing Platonic dialogues. After an introduction of the Middle Platonist view on Platonic syllogistic as present in Alcinous, this paper presents an overview of its application in the syllogizing (...) practice of Proclus and others. That overview shows that the two types were considered two sides of the same coin, to be used for the appropriate occasions, and both relying on the methods of dialectic as revealing the structure of knowledge and reality. Pragmatics, dialectic, and didactic choices determine which type or combination is selected in syllogizing Plato. So even though there is no specific Neoplatonic logic, there is a specific Neoplatonic use of LAS. (shrink)