This chapter identifies three key features of theological discourse in the Roman empire during the first six centuries CE. First, theological language remained shared across the ‘pagan’–Christian divide. Secondly, truthfulness of religious practice was a central theological concern. Thirdly, theology progressively became the remit of professionals, philosophers and bishops. Offering an alternative understanding of the Christianisation of the Roman empire, the chapter argues that, from a Certeaunian perspective, the loss of plausibility that Late Antique ‘paganism’ suffered is reflected in the way in which Neoplatonist discourse distorted the balance between theology and ritual by fully subsuming the latter to the former.

This chapter investigates whether Proclus employs a distinction akin to the Fregean subsumption/subordination distinction to cast light on puzzling claims in the Sophist, such as ‘Motion is at rest’. It argues that Proclus distinguishes predicates true of a Form’s nature from those true by participation to avoid contradiction. The chapter concludes that Proclus’ account, while ingenious, suffers from logical and ontological flaws, cautioning against its adoption for interpreting Plato.

‘Economics’, i.e., household ethics, was included in the Late Antique ladder of sciences as a branch of practical philosophy. In Chapter 13, a preliminary sketch is proposed of this science, its topics and the authoritative texts to be used in its study. Comparing some chapters of Porphyry’s Life of Plotinus and of Marinus’ Life of Proclus, I show how in these texts Plotinus and Proclus exhibit exemplary practice in household ethics and how Marinus’ portrait of Proclus attempts to show his superiority in comparison with Porphyry’s portrait of Plotinus. I also indicate further texts where more material can be found concerning Late Antique Platonist household ethics.

Four levels of music are distinguished by Proclus, going from audible music, through harmonics (theoretical music) up to the highest, divine music, that of philosophy as assimilated to the divine. Bringing these four levels of music into relation with the scale of virtues, I describe how audible music can have a role in the education of irrational affects on the level of ‘ethical’ virtue. On the level of ‘political’ virtue, harmonics provide knowledge inspiring political virtue and which is of use in producing morally beneficial audible music. I note how Proclus, in dealing with these themes in relation of Plato’s association of virtues with musical concords, made use of Ptolemy’s Harmonics and how Damascius both provides more information about Proclus’ views and criticizes them. Finally, I refer to the highest levels of music and their relation to the highest levels of virtue, where plurality and differentiation (in music and virtue) are finally absorbed in unity.

Chapter 4 discusses the protreptic structure of Iamblichus’ De communi mathematica scientia and of Proclus’ revision of this text in the First Prologue to his commentary on Euclid’s Elements. I note rhetorical patterns and styles of argumentation used by Iamblichus, which mean, for example, that the same arguments can be made both in support of the study of philosophy (in the Protrepticus) and in support of the study of mathematics (in the De communi mathematica scientia). I note Proclus’ use of Syrianus’ commentary on Aristotle’s Metaphysics in his revision of Iamblichus’ book and suggest that Iamblichus may have been influenced by the prolegomena of Ptolemy’s Syntaxis.

Chapter 25 introduces Alexander of Aphrodisias’ systematic reading of Aristotle’s Metaphysics. I show how Syrianus took over Alexander’s reading of Aristotle, combining it with Plato’s references to a supreme knowledge, ‘dialectic’, and explaining the possibility of scientific knowledge of the objects of metaphysics – transcendent divine first principles – in terms of concepts innate in the soul which both image these first principles and are available to discursive reasoning as sources of knowledge of these principles. The primary text for metaphysics, according to the Platonists, was Plato’s Parmenides. I show how Proclus’ interpretation of the Parmenides, inspired by Syrianus, underlies the composition of Proclus’ metaphysical masterpiece, the Elements of Theology. Finally, Damascius is shown to have brought out to the fullest extent the limits of human reasonings about transcendent divine principles, reasonings which incessantly lead to contradictions and impasses, the aporetical ‘birth-pangs’ of the reasoning soul where it meets what transcend it.

Only two complete works on the philosophy of mathematics survive from Antiquity, Iamblichus’ De communi mathematica scientia and Proclus’ commentary on Euclid’s Elements Book I. Chapter 21 lists works by Proclus concerning mathematics and the sources he used in these works. Concentrating on Proclus’ commentary on Euclid, I describe his conception of the ontological status of the objects with which mathematics is concerned: these objects are originally concepts innate in human soul, forming part of its very nature, concepts which the mathematician then seeks to articulate, project, construct through various methods so as to constitute an elaborated science. I present also the distinctions made between the mathematical sciences and their methods, the importance of mathematics for other sciences (both superior and inferior to it), and Proclus’ relations with other mathematicians of his time.

The way in which Proclus’ Elements of Theology exemplifies metaphysical science as understood by Late Antique Platonists and as expressed in Proclus’ commentary on Plato’s Parmenides is examined in Chapter 27, which proposes an analysis of the propositions and demonstrations which open the book. I stress the idea that these metaphysical reasonings were regarded as ‘exercises’ of the rational soul, a training leading to a greater proximity to divine first principles.

Plotinus provided an explanation of evil which was original and philosophically challenging. While deriving everything from one source, the absolute transcendent Good, Plotinus does not trivialize the phenomenon of evil or reduce it to human moral deviation, as do other philosophical and religious approaches, but traces evil back to a metaphysical principle, matter, the source of evil in the world and in human souls. In Chapter 11 I present Plotinus’ account of evil and discuss to what extent it can be defended against a series of criticisms formulated by Plotinus’ successors, in particular by Proclus.

Why are states evil? In Chapter 17 I approach this question in relation to Plato’s analogy between soul and city, as this analogy was interpreted by Platonists in Late Antiquity. I indicate first that individual souls belong originally, according to the Platonists, to a transcendent, intelligible community, a city of souls where they enjoy an ‘intelligible love’, a ‘divine friendship’. However, souls, in their presence in the material world, can become alienated by this world, alienated from their original community and from each other. I show that a relation is made between Plato’s account of successive stages of degradation in political constitutions in the Republic Books VIII and IX and stages of moral alienation in souls. Corrupt souls produce corrupt states and corrupt states can corrupt souls.

Chapter 18 introduces the theory of natural law to be found in Plotinus and in Proclus in connection with the interpretation of Plato’s Timaeus. Natural law derives from the ‘law of being’ which is divine Intellect and from souls which, in their nature, are laws unto themselves (autonomous). Divine and natural law are considered as paradigmatic for human law. I explore this relationship as it is presented in Proclus and as exemplified in the idea of rulership for women. Appropriate knowledge in metaphysics and physics is required of the legislator in formulating corresponding human law.

Chapter 20 presents the way in which Proclus interpreted the figure of the tyrant in Plato’s dialogues. Tyranny is based on force, violates law, both cosmic and human, and is motivated by a misled desire for power, power divorced from goodness and knowledge. I argue that Proclus and other Platonists, Damascius and Simplicius, could use this interpretation of Plato to describe the political regimes of their period, in particular the rule of Emperor Justinian, as tyrannies. These tyrannies, in their metaphysical ignorance and moral turpitude, violated divine order and law in destroying pagan temples and statues. I consider finally the cases of two authors, John Lydus and Procopius of Caesarea, who describe Justinian’s rule in terms of kingship or tyranny.

The second chapter concerns the origin of motion in the universe. While Plato assumes a self-moving soul as origin, Aristotle posits an unmoved intellect. Proclus brings these two views together by regarding the unmoved intellect as ultimate source of motion and the self-moving soul as an intermediary entity. I demonstrate that his harmonisation effort goes beyond previous Platonist attempts due to the philosophical reasoning he provides. I also defend Proclus’ assumption of both unmoved intellect and self-moving soul as sources of motion against concerns brought up in scholarship.

The fourth chapter examines the problem of the causality of the unmoved mover. This issue is central in scholarship on Aristotle and goes back to late antiquity. I argue that here Proclus’ non-harmonist stance towards Aristotle emerges most strongly: not only did Aristotle fail to make the intellect an efficient cause of the cosmos’ being but his metaphysics generally is deficient, since he did not recognise the Platonic One as the highest principle. I contrast Proclus’ view with the position of Ammonius and Simplicius who see a complete agreement between Plato and Aristotle.

In this introduction, I outline Proclus’ relationship with Aristotle and provide an overview of the state of the art. I discuss Proclus’ views on the so-called harmony of Plato and Aristotle and contrast it with the views of other, contemporary Neoplatonists, showing that Proclus stands out as more critical of Aristotle. I show that the concept of motion provides a perfect avenue for understanding how Proclus sees the tension between Plato and Aristotle. Lastly, I explain how Proclus differentiates distinct levels of motion which also structure my discussion in the monograph.

While it is common to compare Boethius’ philosophy with that of his intellectual predecessors and heirs, as far as I know there are no studies comparing Boethius and his most well-known Greek contemporary, Dionysius the Areopagite. Yet both were Christians who were inspired by Plato and deeply influenced by Proclean Neoplatonism. This chapter begins to fill this lacuna in the literature by comparing the way that Boethius in the Consolation of Philosophy and Dionysius in On Divine Names employ key Neoplatonic ideas and metaphors in speaking and thinking about God’s nature and providence. The chapter compares how Boethius and Dionysius employ Neoplatonic sphere and circle metaphors (1) to illustrate how God is both completely simple and yet also has, or rather is, a multiplicity of “attributes” or activities, and (2) to articulate the relationship between God and creatures in terms of remaining, proceeding, and reverting.

Chapter 3 takes up the Elenctic section of the dialogue, in which Socrates begins to chisel away at Alcibiades’ hubris in an effort to expose his double ignorance, that is, his ignorance of his ignorance. The young man hastens to the Athenian bema, eager to give a speech about justice, but estranged from justice beyond the level of ethical virtue. Without self-knowledge, he desires nothing other than the accolades of the many and asks not even the simplest question about justice, to say nothing of ascending to contemplate it as intelligible reality. Socrates refutes him in order to remove his arrogant pretension, not only that he knows justice, but that he knows himself. Generally, the Elenctic section removes the obstacles that stand in the way of Alcibiades’ conversion, and the Neoplatonic student learns that he must undergo a similar cleansing to that of Socrates’ interlocutor – Alcibiades’ purification is that of any philosophical initiate.

The first chapter begins the project of weaving together the commentaries of Proclus and Olympiodorus, and argues that both commentators attempt nothing less than a transfiguration of the human soul and its reorientation toward the desiderative longing characteristic of the contemplative life, the consequence of which is their student’s ascent through the hierarchy of virtues that Neoplatonic pedagogy coordinates with the reading of particular Platonic dialogues. The Alcibiades I, with the commentator’s direction, is the doorway through which an initiate must pass, enduring a cleansing that shepherds him toward the sanctum of the real. The Neoplatonic analysis of the dialogue’s thematic structure is also adumbrated: Socrates proposes that Alcibiades change how he lives only to undermine what he wants and finally concludes that Alcibiades is misguided about both because he assumes a mistaken conception of who he is. This progression is itself framed on both sides by eros.