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)

An aporia posed by Theophrastus prompts Priscian to describe the process by which perception formally assimilates to its object as a progressive perfection. I present an interpretation of Priscian’s account of perception’s progressive perfection. And I consider a dilemma for the general class of accounts to which Priscian’s belongs based on related problems raised by Plotinus and Aquinas.

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)

In hisCommentary on the AlcibiadesiProclus often discusses and links the peculiar epistemological category of “double ignorance” with evil and grievous error. To understand this more fully, the following analyzes Proclus’ concept of double ignorance, its characteristics and its causes. Markedly, due to his understanding of double ignorance, Proclus offers a response to the “Socratic” idea that no one willingly errs as this particular category of not-knowing enables him to explain how individuals, despite desiring and in some sense knowing the good, (...) fail or ‘miss the mark’ in articulating and doing the good. (shrink)

Aristotle’s notion of experience occupies an important place in his account of scientific understanding and its methodology. It is linked, not only to sense-perception and the principles of skill and scientific understanding, but also, methodologically, to ἐπαγωγή. Due to its various involvements it has a complex job to perform. Such a complexity – or Janus-face – gives rise to many questions concerning its status and content. Many of these questions were raised in later antiquity. In the introductory part of the (...) paper I shall give a very brief summary of Aristotle’s notion of experience, concentrating on issues that will be relevant next, and then discuss the explanation we find in a commentary which has come down to us under the name of Philoponus. I do it in the hope that the discussion sheds light on novelties in the commentator’s approach which deserve attention. (shrink)

_ Source: _Volume 9, Issue 2, pp 177 - 204 This article presents a synoptic account of the faculties of rational soul in the philosophy of Proclus and an interpretation of the unity which this soul constitutes despite the plurality of its faculties and objects of its attentions. It seeks to demonstrate that Proclus, through his conceptual construction of a rational soul grounded in an objective and cosmic framework, accounts for at least some of the subjective aspects of selfhood which (...) many contemporary philosophical theories take to be necessary for a concept of self, but that he does so on his own terms. This means, among other things, that Proclus posits each rational soul as a subjective entity with its own perspective on the world, but a perspective which is always grounded, more or less, in an objective knowledge of the world which belongs to it essentially and eternally. Despite grounding the subjective in the objective, Proclus is able to account for the individuality and uniqueness of souls within the limits of his objective framework. (shrink)

In his commentary on Plato’sCratylus, Proclus interprets the dialogue not as a mere work on logic or linguistics, but as having a full psychological and theological import.Late ancient Platonists had already proposed a similar reading for another Platonic dialogue,i.e.theParmenides. In that case too they rejected the logical interpretation, and aimed to find in the text the description of the hierarchy of reality, particularly of the highest beings. As a result, theParmenideswas seen as the accomplished expression of Plato’s theology.Proclus too draws (...) a comparison between theCratylusand theParmenidesin order to stress their theological significance. He also contrasts Plato’s dialectic with Aristotle’s dialectic. Proclus’ interpretation of dialectic is best understood if it is compared to the doctrines of his master Syrianus and of one of his co-disciples,i.e.Hermeias, at the Platonic school of Athens in the 5th centuryad.Contrary to what is sometimes assumed, in this milieu Platonists were not always committed to the task of reconciling the philosophies of Plato and Aristotle. As it happens, they could strongly disagree with and even attack Aristotle, and side with Plato. In particular, they greatly valued Plato’s dialectic, which they viewed as the correct form of reasoning and at the same time as a theory of the utmost theological significance. On the other hand, Aristotle’s dialectic was considered as “bare” logic,i.e.as a mere set of logical rules and arguments with no specific contents.On the basis of a problematicCratylus’passage Proclus defends a theory of truth according to which not only propositions, but also names can be true or false. This allows him to view names as substitutes of propositions. This is particularly the case in the application of the four dialectical methods of definition, division, demonstration and analysis. Proclus’ approach arguably provides a basis—to pagan as well as Christian tradition—for the study of divine names as a part of theology, for the name of a god is held to reveal its attributes. (shrink)

While the metaphysical aspects of Proclus' theory of evil have recently been studied by a number of scholars, its ethical implications have largely been neglected. In my paper I am analysing the moral consequences that Proclus' concept of evil has, at the same time using the ethical perspective to throw more light on Proclus' ontology. Most importantly, I argue that the difference between bodily and psychic evil is much more substantial that it might seem from On the Existence of Evils (...) alone. Though both kinds of evil are characterized by their 'parasitical existence' , evil in bodies is unavoidable, resulting from a wide network of cosmic corporeal interactions that no partial being can ever have control of. Psychic evil, on the other hand, is a product of human choice and is independent of external circumstances, depending wholly on the soul's ability to keep its proper vertical hierarchy. In this regard it is evil in a much more serious sense of the word, being actively caused rather than just passively suffered. In the last section of my paper I throw further light on this more dangerous kind of evil, showing it as resulting from an essential bi-dimensionality of human beings. (shrink)

I examine the relation between sensation and discursive thought in Plato, Plotinus, and Proclus. In Theaetetus, a soul whose highest faculty was sensation would have no unified experience of the sensible world, lacking universal ideas to give order to the sensible flux. It is implied that such universals are grasped by the soul’s thinking. In Plotinus the soul is not passive when it senses the world, but as the logos of all things it thinks the world through its own forms.Proclus (...) argues against the derivation of universal logoi from the senses, which alone can’t make the sensible world comprehensible. At most they give a record of the original sense-impression in its particularity. The soul’s own projected logoi give the sensible world stability. For Proclus, bare sensation does not depend on thought, but a unified experience of the sense-world depends on its paradigmatic logoi in our souls. (shrink)

In his commentary on Euclid, Proclus says both that the first principle of geometry are self-evident and that they are hypotheses received from the single, highest, unhypothetical science, which is probably dialectic. The implication of this seems to be that a geometer both does and does not know geometrical truths. This dilemma only exists if we assume that Proclus follows Aristotle in his understanding of these terms. This paper shows that this is not the case, and explains what Proclus himself (...) means by definition, hypothesis, axiom, postulate, and the self-evident, and how geometry is a science that receives its principles from dialectic. (shrink)