Philoponus, John (490–570)

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John Philoponus of Alexandria, a sixth-century philosopher and theologian, is best known for his radical attempts to refute fundamental tenets of contemporary AristotelianNeoplatonic school philosophy. His main historical significance lies in the fact that he anticipated by centuries the early modern emancipation of natural philosophy from Aristotelian dogmatism. Philoponus (literally Lover of Work ), or John the Grammarian, as he called himself, is commonly labeled a Christian Neoplatonist, but this epithet is misleading. Philoponus was a Christian, most likely by birth, and he received the standard philosophical training available at Alexandria in his day. Thus, his philosophical orientation was not a matter of choice, and his fierce rationalism, which he employed also as a tool to resolve controversial questions that divided Christianity, bears no resemblance to the genuine Christian Neoplatonism of Pseudo-Dionysius, the Areopagite (c. 500). Roughly 100 years after his death, the Third Council of Constantinople (680681) condemned his theological doctrines as heresy and thereby curtailed the overall philosophical influence he could have had in later centuries.

Almost everything about Philoponus's life remains a matter of hypothesis. He was born presumably around 490 CE, but it is not known where (Kaster 1988); in the early sixth century, he studied in Alexandria, reading philosophy under Ammonius, Son of Hermias (c. 440520), who had been a pupil of Proclus at Athens. In the early 520s, Philoponus taught both grammar and philosophy at Alexandria; some of his early commentaries on Aristotle are based on Ammonius's lectures, but in the process of multiple revisions, Philoponus added explanations, observations, and criticisms of his own. In the late 520s, early 530s, around the time of Justinian's eviction of the pagan philosophers in Athens (c. 529), Philoponus turns to writing polemical commentaries (on Proclus and Aristotle), which no longer aim at elucidation but at refutation, especially of the pagan doctrine of eternalism. These works provoked immediate condemnation of by Simplicius of Cilicia, a contemporary member of the Athenian School, the last great pagan mind of antiquity and expert commentator on Aristotle.

Although Philoponus was one of the most powerful and independent thinkers of his time, he never succeeded Ammonius as professor of philosophy. The reasons for this are unclear; although unknown external, personal or political circumstances may have played a role, a likely explanation is that Philoponus had reached a point where his fundamental disagreement with the philosophical establishment compromised his ability to continue the pedagogical tradition of the school. Leadership of the philosophical school remained in pagan hands well into the second half of the sixth century. Philoponus's later writings, from the 540s onward, deal with contemporary issues of theological controversy. He expounded his theological views with philosophical rigor, whether rejecting the orthodox belief in the divinehuman duality of the nature of Christ (miaphysitism) or defending the substantial distinctness of the hypostases of the Trinity (tritheism). Philoponus must have died around 570.

Philoponus' œuvre, which bears witness to his interests in grammar, philosophy, psychology, medicine, mathematics, astronomy, and theology, may be divided into three related yet distinct parts (Scholten 1996): (1) The commentaries on Aristotle (Categories, Prior and Posterior Analytics, Physics, On Generation and Corruption, Meteorology, and On the Soul ); (2) the treatises of the critical period, notably, the two monumental polemical treatises On the Eternity of World against Proclus (shortly after 529) and the influential On the Eternity of World Against Aristotle (early 530s, extant only in fragments); and (3) a number of works on theological doctrine, some of which are only extant in Syriac translation; most important of the last group is a still-extant commentary on the biblical creation myth (On the Making of the World, written between 546 and 560) which also targets the naïve Christian cosmography of Cosmas Indicopleustes.

In his philosophical works, one can roughly distinguish between two kinds of criticism: on the one hand, the grappling with implausible Aristotelian theories, mostly physical, and on the other hand, outright repudiation of fundamental cosmological doctrines. Aristotle's definition of light as an incorporeal and instantaneous transition from the potentiality (dunamis ) of a medium to be transparent to the actuality (energeia ) of transparency fails to account for the laws of optics and for the calefactory property of the sun. Philoponus proposes to interpret light as an incorporeal activity rather than a state, capable of warming bodies and comparable to the soul in animals. Later, in the Meteorology commentary, which may be the transcript of his last lecture series on Aristotle, he argues materialistically that light and heat are consequences of the fiery nature of the sun, and that heat is generated when the rays emanating from the sun are refracted and warm the air through friction.

The Physics commentary contains one of his most celebrated achievements, the theory of the impetus, which is commonly regarded as a decisive step from an Aristotelian dynamics toward a modern theory based on the notion of inertia. To what extent Philoponus was influenced by previous philosophical or theological authors is a matter of controversy (Fladerer 2003). His own discussion, at any rate, commences with the expression of dissatisfaction with Aristotle's explanation that a projectile continues to move on account of the air's turbulence generated by the projectile itself. Philoponus proposes instead that a projectile moves on account of a kinetic force that is impressed on it by the mover and that exhausts itself in the course of the movement. In short, the medium contributes nothing to a projectile's motion; rather, it impedes it. Moreover, Philoponus holds that there is nothing to prevent motion from taking place in the void.

Occasionally, Philoponus resorts not only to thought experiments but also to pertinent observations that resemble physical experimentation. Aristotle's verdict that the speed of a falling body is proportional to its weight and indirectly proportional to the density of the medium is challenged by the same kind of empirical evidence that Galileo mustered centuries later.

Philoponus is critical of Aristotle's conception of space. He substitutes Aristotle's definition of the place of a body (the inner surface of that which contains it) with a conception of three-dimensional extension, its volume. Likewise, the most fundamental level of physical reality is not some mysterious prime matter but three-dimensional, indeterminate, and unqualified corporeal extension, a concept reminiscent of Descartes's res extensa.

The issue at stake in the two polemics against Proclus and Aristotle is the question of the contingency of the world. The earlier work obliterates a pamphlet of eighteen arguments for the eternity of the world written in the previous century by the powerful Neoplatonist Proclus. The lost Against Aristotle tackled influential arguments for eternity in On the Heavens I and Physics VIII. In both cases, Philoponus succeeds in pointing out numerous contradictions, inconsistencies, fallacies, and improbable assumptions. One clear casualty is Aristotle's peculiar postulate of an incorruptible celestial element (ether). The observable irregularities in the heavens, their complexity and changes in color, undermine the thesis of the radical ontological difference between the celestial and sublunary regions. Dissecting the text in unprecedented ways, Philoponus even paves the way for influential demonstrative arguments for noneternity. Although Philoponus concedes that in nature nothing comes to be from nothing, he offers the first philosophical defense of the Christian belief that God created the world ex nihilo. In the late theological treatise On the Making of the World, Philoponus suggests in passing that the celestial bodies were set to spin by a powerful impetus at the time of their creation and that they now continue to move not on account of their own nature but by the will of God.

It is impossible to gauge how Philoponus's ideas resonated with Christians during his lifetime. He was read and admired by Syrian and, to some extent, Islamic philosophers, but the anathema of 681 severely hampered the further propagation of his theological and philosophical work. As Simplicius before them, later thinkers like Thomas Aquinas (12241274) and Zabarella (15331589) roundly rejected Philoponus. Eventually, the arguments against eternity persuaded Bonaventure (12171274) and Gersonides (12881344), and the theory of the impetus was reaffirmed by Buridan (12951356) and Oresme (13251382). In the sixteenth century, the first editions as well as numerous translations (into Latin) of the commentaries and the treatise against Proclus began to appear in print. In particular, Philoponus's criticism of Aristotle in the Physics commentary was widely discussed and persuaded such diverse thinkers as Gianfrancesco Pico della Mirandola (14691533) and Galileo Galilei (15641642).

See also Aristotelianism; Bonaventure, St.; Buridan, Jean; Galileo Galilei; Gersonides; Impetus; Neoplatonism; Oresme, Nicholas; Pico della Mirandola, Gianfrancesco; Proclus; Pseudo-Dionysius; Simplicius; Thomas Aquinas, St.; Zabarella, Jacopo.


major works

On the Use and Construction of the Astrolabe, edited by H. Hase. Bonn: Weber, 1839 (ibid., Rheinisches Museum für Philologie 6, 1839, 127171). Reprinted and translated into French by Alain P. Segonds, Jean Philopon, traité de l'astrolabe. Paris: Librairie Alain Brieux, 1981. Translated into English by H. W. Green in The Astrolabes of the World. Vols. 1 & 2. Robert T. Gunther. Oxford: University Press, 1932; Reprinted, London: Holland Press, 1976, pp. 6181.

Commentary on Aristotle's Physics. In Commentaria in Aristotelem Graeca, XVIXVII, edited by H. Vitelli. Berlin: Reimer, 18871888. Philoponus's most important commentary in which he challenges Aristotle's tenets on time, space, void, matter, and dynamics; there are signs of revision. Partial translations: Philoponus, On Aristotle's Physics 2, by A. R. Lacey. London: Duckworth, 1993; Philoponus, On Aristotle's Physics 3, by M. Edwards. London: Duckworth, 1994; Philoponus, On Aristotle's Physics 58, by Paul Lettinck. London: Duckworth 19931994; Philoponus, Corollaries on Place and Void, by David Furley. London: Duckworth, 1991.

On the Making of the World (De opificio mundi ), edited by Wilhelm Reichardt. Leipzig: Teubner, 1897. Greek text and German translation by Clemens Scholten. De opificio mundi = Über die Erschaffung der Welt. Freiburg, New York: Herder, 1997. A theologicalphilosophical commentary on the Creation story in the book of Genesis, written probably 557560.

On the Eternity of the World against Proclus (De aeternitate mundi contra Proclum ), edited by Hugo Rabe. Leipzig: Teubner, 1899. Reprinted, Hildesheim: Olms, 1984. Translated by Helen S. Lang and Anthony D. Macro. De aeternitate mundi. English and Greek. Berkeley: University of California Press, 2001. A detailed criticism of Proclus's eighteen arguments in favor of the eternity of the world.

On the Eternity of the World against Aristotle (De aeternitate mundi contra Aristotelem ). Not extant; fragments reconstructed and translated by Christian Wildberg. Philoponus, Against Aristotle on the Eternity of the World. London: Duckworth, 1987. A refutation of Aristotle's doctrines of the fifth element and the eternity of motion and time consisting of at least eight books.

further reading

Fladerer, Ludwig. "Johannes Philoponos, Gregor von Nyssa und die Genese der Impetustheorie." In Hommages à Carl Deroux V, edited by Pol Defosse. Collection Latomus 279 (2003): 138151.

Haas, Frans A. J. de. John Philoponus' New Definition of Prime Matter: Aspects of its Background in Neoplatonism and the Ancient Commentary Tradition. Leiden, New York: E. J. Brill, 1997.

Kaster, Robert A. Guardians of Language. The Grammarian and Society in Late Antiquity, 334338. Berkeley: University of California Press, 1988.

Sambursky, Samuel. The Physical World of Late Antiquity, 154175. London: Routledge and Kegan Paul, 1962.

Scholten, Clemens. Antike Naturphilosophie und christliche Kosmologie in der Schrift "De opificio mundi" des Johannes Philoponos. Berlin: De Gruyter, 1996.

Sorabji, Richard R. K. Matter, Space, and Motion, 227248. London: Duckworth, 1988.

Sorabji, Richard R. K., ed. Philoponus and the Rejection of Aristotelian Science. London: Duckworth, 1987.

Sorabji, Richard R. K. Time, Creation and the Continuum, 193231. London: Duckworth, 1983.

Verrycken, Koenraad. "The Development of Philoponus' Thought and Its Chronology." In Aristotle Transformed, edited by Richard R. K. Sorabji, 233274. London: Duckworth, 1990.

Wildberg, Christian. "Impetus Theory and the Hermeneutics of Science in Simplicius and Philoponus." Hyperboreus 5 (1999): 107124.

Wildberg, Christian. John Philoponus' Criticism of Aristotle's Theory of Aether. Berlin: De Gruyter, 1988.

Christian Wildberg (2005)