Denis Walter

John Italos follows his teacher Psellos in describing ousia as authypostaton or authyparkton. While in Psellos on ousia, noes and psychai are paradigmatic examples, bodies also fall into this category to a lesser degree. Italos is not so detailed in the manner of fine subtlety, but adopts the same scheme. Both authors are in the tradition of John of Damascus, who is their first authority for dealing with this problem. Psellos offers different criteria, while Italos follows more clearly the traditional explanations and chooses between them the one he considers most plausible.

Although Psellos does not formulate a clear theory of 'female' or gender, he makes reference to women in many instances throughout his works. The tradition that he stands in gives him the opportunity to reformulate affirmations of the equality of the sexes, particularly regarding the possibility to become virtuous. Nevertheless, a closer look at the relevant passages reveals the fact that he never discusses women that are theoretically active— meaning investigating created nature. Yet one striking similarity among the many presentations of women in his works is that they are philanthropically active. Even though friendship and philanthropy are not described solely as an activity 'appropriate' to women, the frequency of this combination—together with the absence of any comparable combination of women and theoretic activity—points to an underlying concept of intellectual inferiority of women. Psellos would have had enough examples to use (Macrina, Diotima, etc.) had he wanted to underscore the few passages that speak about equality. Neverthe-less, aside from a few remarks, he seems to ascribe to women neither passivity (cf. the philanthropic activity), nor aesthetic materiality (cf. the role of a good soul for beauty), nor any imperfection of 'female souls' regarding emotionality (cf. the asceticism of his mother). The only critique he formulates seems to be that of not being theoretically active.

Alongside the apoion sôma, which Proclus is well known to designate as the first three-dimensional entity, we find a further 'first' three-dimensional entity: namely the sphere, which appears in the projection of geometrical objects in the phantasia. Finally, Proclus also speaks of a third level at which three-dimensionality occurs, one situated, as it were, between the two just mentioned: in nature. It will emerge that each of these three modes in which body appears is subject to its own organizing principle: in the geometrical domain of the phantasia it is the circle, in nature the elementary triangle, and below that — so far as this is possible — body itself. Proclus thus treats corporeality under several different aspects. We will find that he proceeds in the domain of corporeality just as he does in the intellectual domain, by distinguishing three "triads," each headed by one of its own elements as its organizing principle. This allows more precise bodies to be distinguished from less precise ones, depending on which of these three organizing principles they fall under. The least precise form of corporeality — as may be surmised from its systematic position and its determinations — corresponds to the apoion sôma.

This chapter investigates the origin of incommensurability within Proclus’ ontology through an analysis of his Commentary on the First Book of Euclid’s Elements and his Commentary on the Parmenides. The central question concerns how incommensurability arises at a specific ontological level and how it corresponds to a distinct mode of cognition. The chapter first situates geometrical entities in an intermediate position between the intelligible and the sensible realms. It then demonstrates that sensible matter cannot serve as the unqualified cause of incommensurability, since it accounts only for imprecision rather than for incommensurability. Likewise, intelligible matter (the soul) alone cannot explain it, as not all objects within the soul exhibit incommensurability. Instead, the chapter argues that incommensurability is an intrinsic property of certain geometrical entities, comparable to their other identifiable features. Ultimately, the essay supports the interpretation that incommensurability is a definable and necessary feature of some geometrical objects.

This book presents a constructive interpretation of Plato’s Parmenides. It offers a close reading of the dialogue’s first part and shows how the second part takes up its problems while unfolding a philosophical project that reaches beyond them. The reader is guided through the exercise as Denis Walter shows how it articulates a complex ontology, addressing the hierarchy of forms, definitions, participation, mathematical structure, and teleology. By organizing the argument around philosophical topics rather than deductions, the study brings into view a coherent ontological framework extending from the One to unlimited multitude. The book offers a clear and philosophically grounded reading of one of Plato’s most demanding texts.

Michael Psellos ist ein Philosoph, der wie kein anderer für die byzantinische Epoche steht. Das Denken dieses Großintellektuellen – der in subtilen Auseinandersetzungen mit antiken und spätantiken Positionen in Theologie, Ontologie und Ethik eine selbständige christliche Philosophie formuliert – findet in diesem Band erstmalig eine monographische Gesamtdarstellung. Die Arbeit liefert durch ihren systematischen Charakter, durch die Einbeziehung bisher nicht interpretierter Texte, durch die Darlegung der bisherigen Forschungsergebnisse und durch die Aufdeckung von Traditioinslinien eine wichtige Grundlage für die weitere Erforschung der byzantinischen Philosophie.

The Byzantine philosopher Michael Psellos describes in his ethics two kinds of virtue: practical and intellectual virtues. Practical virtues are defined as a middle term between two extremes as is known from the Aristotelian tradition. His innovation is to define also a middle regarding the intellectual virtues. He says that the highest object of knowledge is not graspable for the human intellect because it exceeds his powers. Whoever strives to understand the highest object of knowledge, the essence of god, is determined to fail. Thus, the best objects that the human intellect can contemplate are situated below god, in the “middle”. The concept of the middle is thus present twice in Psellos’ ethics: once in the practical virtues and once in the intellectual virtues.

Among the Neoplatonists read by Byzantine thinkers, Plotinus does not rank first. He is surpassed by Proclus, who enjoys a livelier reception. Nevertheless, many Byzantines refer to Plotinus’ Enneads. In this chapter we present the impact he had on the Byzantines from the 5th to the 15th century, namely on John of Scythopolis, John of Damascus, Michael Psellus, Symeon Seth, John Italus, Michael VII. Doukas, Michael of Ephesus, Nicolas of Methone, Nicephorus Blemmydes, Theodorus II. Doukas Laskaris, Georgius, Pachymeres, Maximus Planoudes, Nicephorus Chumnus, Constantinus Akropolites, Theodorus Metochites, Nicephorus Gregoras, Palamas, Georgius Gemistus Plethon, Bessarion, Georgius Gennadius Scholarius, Michael Apostoles. What unites these very different thinkers is that they measure Plotinus, and ancient philosophy in general, by the standard of Christian teaching.

In the following article, I compare ancient cosmopolitanism with Kant’s cosmopolitanism. I argue that we have to distinguish between different approach- es in antiquity, not all of which are suitable for a comparison with Kant. In antiq- uity, we can distinguish at least three different theories of cosmopolitanism, one that rejects territorially limited states as unnatural conventions, a second that de- scribes only the wise as cosmopolitans, and finally a third for which belonging to the human species is already sufficient to be part of the comprehensive commu- nity, and which, at the same time, allows for territorially limited states. For a close examination of the possible parallels, I will compare these with four concepts of Kant’s theory that have been claimed in research to have similarities to ancient positions, namely the ius cosmopoliticum and hospitality, the formula of humanity as an end in itself, the kingdom of ends, and the ethical community.