John Philoponus and the Controversies over Chalcedon in the Sixth Century: A Study and Translation of the Arbiter by Uwe Michael Lang (Spicilegium Sacrum Lovaniense. Peeters) The Alexandrian polymath John Philoponus (c. 490‑575 AD) is best known to scholars as the outstanding philosopher from the Neoplatonic school of Ammonius Hermeiou (435/445‑517/526 CE) and prolific commentator on Aristotle who launched an overall attack on the dominant Aristotelian scientific world‑view of his day. Among historians of ancient thought his reputation as one of the most original thinkers of late antiquity has been established for some time. Philoponus the Christian theologian, however, has not attracted such scholarly enthusiasm. Patristic research often concentrated on the intricacies of the Trinitarian and Christological debates of the fourth and fifth centuries, and was inclined to underestimate the gravity of the controversies in the aftermath of the Council of Chalcedon in 451. This has changed in recent years, and considerable attention is now given to post‑Chalcedonian Christology. It is one of the major achievements of the monumental work by the late A. Grillmeier to have gathered together the highly specialized research undertaken in various departments of academia. Still, only a few, far from comprehensive studies have been devoted to the specifically Christian doctrines of the Alexandrian philosopher and lay‑theologian Philoponus.

The main purpose of Philoponus' literary endeavour in the Arbiter and the subsequent treatises was a defense of miaphysitism and a critique of Chalcedonian Christology. It is appropriate, then, to inquire into his relationship to the dogmatic definition of the Council. There can be no doubt that he understood it Aristotelice et non piscatorie, after the manner of Aristotle, not of a fisherman ‑ indeed, there are not too many others to which this applied so accurately. When the Codex Encyclicus was compiled between 457 and 459 at the initiative of the Emperor Leo I, the group of Greek bishops led by Euippus characterised their approach to Chalcedon with the following words: haec ergo breviter piscatorie et non Aristotelice suggessimus". From the early decades of the sixth century, however, the prevalent attitude towards Chalcedon had shifted from this "pastoral" breadth to a focus on the speculative implications of the Council's dogmatic formula, which seemed so contrary to common intuitions. This debate "after the manner of Aristotle" was all too often marked by sharp polemics about the technical subtleties of the formula, with a tendency to ignore the kerygmatic aspect of the definition of faith. Whether or not the work of Timothy Aelurus proved to be the decisive moment in this shift, as Grillmeier has suggested, may be left unanswered here. The results of this acrimonious controversy were often deplorable. However, this fact does not discredit the attempt to work out the speculative content of the formula. It certainly seems to be a task required for the articulation of the intellectus fidei.

I should like to argue that the speculative content of Chalcedonian Christology is not too far from that of Philoponus. This is even more true for the Cyrilline reading of the Council's definition given by such sixth‑century theologians as John of Caesarea and Leontius of Jerusalem. Philoponus' antagonism towards the Council was thus mainly owing to the conceptual strictures which he imposed on Christology. Be cause of his identification of particular nature and hypostasis the Chalcedonian distinction between the level of hypostasis, where unity is effected, and the level of nature, where duality is preserved, appeared to him wholly incomprehensible. But is it really more legitimate to speak of one nature or substance with incompatible properties, rather than two natures with their own? Does Philoponus' conception avoid the logical difficulties of Chalcedon, or does he just transfer them onto another level? It was the merit of Chalcedonian orthodoxy, when it affirmed that the two natures of Christ are united xaA' bnocriacytv, not xaia (pucytv (as in canon VIII of the Second Council of Constantinople), that it secured the full reality of the God‑man Christ who is consubstantial with the Father with regard to his divinity and consubstantial with us with regard to his humanity. Evidently, Philoponus' emphasis on the undiminished divinity and the undiminished humanity of Christ prevented him from the extremist position of Eutyches and from any "realmonophysitism". At the point, however, where the divine and the human, the eternal and the temporal, the immaterial and the material meet, the answers Philoponus gave were deficient.

Philoponus explicitly aims at bringing order into the mess of the post-Chalcedonian controversies by subduing Christology to a rigorous logical clarification. The categories according to which he judges the validity of different positions are strictly philosophical. However, Philoponus does not succeed in providing a logically coherent alternative to the definition of the Council. Indeed the principal question is whether his project is not inherently flawed. While the divine realities enjoy an innate intelligibility and thus allow for theological investigation, they remain in the half‑light of the mystery, which can never be elucidated entirely by rational enquiry. In this respect the Arbiter leaves a far too confident impression of what can be achieved at all. Notwithstanding this methodological caveat, the kerygmatic scope of the Chalcedonian definition, the affirmation of the reality of divinity and humanity in the one person of Jesus Christ, calls for an ontological clarification. Hence Aristotelice versus piscatorie is a false alternative in the understanding of the Council. Chalcedon itself does not provide a developed Christology, but the valid criteria for theological reflection about the person and work of Jesus Christ. It is by these criteria that Philoponus' forceful defense of a miaphysitic Christology should be measured.