SOURCE: Warren, Edward W. Introduction to Porphyry the Phoenician: Isagoge, translated by Edward W. Warren, pp. 9-23. Toronto, Can.: The Pontifical Institute of Mediaeval Studies, 1975.

[In the following excerpt, Warren presents some biographical background on Porphyry before discussing his Isagoge in the context of the logical tradition and metaphysics, moving on to discuss Boethius's commentaries on the work.]

PORPHYRY

Porphyry was born at Tyre in Syria about 232 A.D. and died in Rome sometime between 301 and 306 A.D. He was educated in Syria and in Athens where he came under the influence of Longinus, who like Plotinus and the pagan Origen had been hearers of Ammonius Saccas in Alexandria. Longinus was a man of great learning, and Porphyry undoubtedly absorbed much of his knowledge of Greek philosophy at this time. Even after his departure he continued to be in touch and corresponded with Longinus. He went to Rome in 263 and became an ardent adherent of the neoplatonism of Plotinus, later editing the Plotinian Enneads and writing his Life of Plotinus. He stayed in Rome for six years. Later, when he became acutely depressed, Plotinus urged him to travel. He went to Sicily where he busied himself with Aristotle's writings as well as with other work, notably his polemic Against the Christians. Here, too, he wrote the Isagoge (a transliteration of the Greek Εἰσαγωγή, or Introduction) for Chrysaorius, a Roman Senator, who had come upon Aristotle's Categories and could not make any progress. Chrysaorius wrote for help; but, since Porphyry could not return, he wrote his Introduction. This little work, written so much by chance, was destined for great popularity throughout the middle ages and even recently was praised by A. C. Lloyd: “In fact Porphyry's Isagoge and his elementary commentary on the Categories are admirable introductions to the concepts of Aristotelian logic.”¹

His reputation during late antiquity was substantial and his influence considerable in the philosophical community. Porphyry's commentaries on Aristotle's logic established a tradition whereby young philosophers began philosophy with Aristotle's Organon. In the neoplatonic schools in Athens and Alexandria Aristotle became the logician and the philosopher of the natural world, while Plato became the theologian. The notion that Plato and Aristotle were in harmony was partially purchased at this time by assigning to each different spheres of interest.

While Porphyry was in Sicily, Plotinus died (270 A.D.), and it fell to Porphyry to return to Rome to take his mentor's place. He became famous as an interpreter of the difficult and frequently obscure doctrines of Plotinus. Late in life he married the widow Marcella, for whom he wrote a consolation while he was absent from home, an absence apparently caused by political pressures. Sometime after 298, Porphyry published the Enneads of Plotinus. Within a few years he died, and the center of neoplatonism shifted to the Near East and to Iamblichus who was perhaps a student of Porphyry.²

THE LOGICAL TRADITION

The significance of Porphyry's modest Isagoge is determined largely by the controversy over universals that arose during the middle ages and by the metaphysics developed with the aid of Aristotelian logic. The Isagoge is not an original contribution to metaphysics or logic nor is it intended to be. Rather it is an introduction to, an attempted explanation of, the Aristotelian terms later called predicables. His purpose was to help the student understand the Aristotelian text by making clear the meanings of genus (γὲνοs), species (ει̑δοs), difference (διαφορά), property (ἴδιον), and accident (συμβεβηχόs). Aristotle discusses the predicables in detail in the Topics, a largely early work according to current scholarship, and it is on this Aristotelian treatise that Porphyry builds his Isagoge. Aristotle's predicables are definition (ὅροs, ὁρισμόs), property, genus, and accident. Porphyry altered the list by adding species and difference but eliminating definition. An Aristotelian definition, of course, is obtained by adding a difference to the genus to obtain the species.³

The historical influence of the work is traceable (1) to its opening page where Porphyry lists a few deeper issues concerning the kind of existence enjoyed by generic and specific terms, (2) to its translation by Marius Victorinus and by Boethius,⁴ and (3) to its publication as the initial treatise in subsequent Latin editions of Aristotelian logical works. The Isagoge became a standard preface to work in Aristotle's logic. As long, then, as Aristotle's logic was taken as a foundation for human speculation, the utility of Porphyry's work was clear, and his brief explanation of genus, species, and the rest was useful. Since logic was modus sciendi, students began philosophy with logic, a practice that, although continued into the 20th century, has broken down as logic has become increasingly formalized and removed from ordinary language. In contemporary textbooks of logic, one is apt to find no mention of Porphyry or of the predicables. The formal mathematical logic of the mid-twentieth century largely absorbed Aristotelian formal principles into a class logic and generated in its course profound controversies over the relation of formal languages to natural languages and of language to thought; and once again, in somewhat different guise, the kind of existence or, as we are apt to say in modern terminology, meaning to be attributed to general terms came under close examination.

The startling developments in formal logic at the end of the 19th century led to more serious attempts by scholars to trace the development of logic, especially formal logic, and a few excellent histories of the subject have appeared. At the same time more detailed work was begun and reappraisals made of the contributions of Stoic and mediaeval logicians. Such a renewal of interest allows us to reconstruct gradually and ever more accurately the history of logical theory.

Though the germs of logical theory arose in the 5th century B.C. in Zeno of Elea, the Sophists, the mathematicians, and Plato, it is in Aristotle's Organon that the first attempt was made to systematically examine the formal structure of reasoning. The editors of Aristotle's work grouped the treatises as follows: Categories, On Interpretation, Prior Analytics, Posterior Analytics, Topics, and On Sophistical Refutations. For many moderns much of the subject-matter is not germane to formal logic but includes practical advice about argument, discussions of epistemology and the theory of science, metaphysical claims, and so on. The dominant impression is that Aristotle, while acutely attuned to the problems of formalization, which were likely most critical for the mathematicians of his day, was mainly concerned with providing a set of argument forms and rules that would support an adequate theory of science as a basis for his research into φύσιs and τὰ ὄντα. The introductory work, the Categories, is a difficult, if compact work, whose purpose has frequently been debated. J. L. Ackrill represents the contemporary consensus:

… it is important to recognize from the start that the Categories is not primarily or explicitly about names, but about the things that names signify … Aristotle relies greatly on linguistic facts and tests, but his aim is to discover truths about non-linguistic items.⁵

Modern formal logicians have tended to regard the inclusion of the Categories in the Organon as unfortunate since the focus is metaphysical and not formal. Whether logic can or ought to be limited to formal structure or can be successfully separated from metaphysics is an open question and has been the subject of intense debate much of the past 50 years. Whatever the truth in this matter, the Categories profoundly influenced logic, for good or ill, until recent times, so that the Isagoge enjoyed a similar prominence and importance.

A second strain of logic in antiquity stems from Zeno of Elea, the Megarians, and Stoics who developed the theory of complex propositions, especially conditionals, into a central position in logical theory. Stoic logic, called dialectic by them, attained great prominence and was viewed by some as an alternative to the Aristotelian, although in truth their theories of formal logic were complementary. The energy devoted to logic by the early Stoics was remarkable and was due to the major importance it had for their philosophy. Their speculations in dialectic touched upon epistemology and grammar as well as formal logic, and several of their theories, especially those of the λεχτόν and ἀξίωμα, show great subtlety. In contemporary logical theory the calculus of propositions developed by the Stoics, particularly Chrysippus, is fundamental to the presentation of Aristotle's logic of general terms.

Within this scheme Aristotle's syllogistic takes its place as a fragment of general logic in which theorems of primary logic are assumed without explicit formulation, while the dialectic of Chrysippus appears as the first version of primary logic.⁶

No adequate combination of the contributions of the Peripatetics and the Stoics was accomplished in late antiquity or in the middle ages, and the fate of progress in logical theory was tied to other philosophical and theological issues.

The major figure in the transmission of logical theory to the later middle ages was Boethius, whose translations and commentaries on Aristotle's works were the chief source of knowledge. Boethius translated the Isagoge and wrote two commentaries, the first based on the Latin translation of Victorinus and the second based on his own version. The appearance of the Isagoge at the head of these writings insured its importance. Boethius chose to comment on the deeper questions mentioned in Porphyry's opening section and so stimulated interest in the signification of terms and problems of meaning. The ensuing controversy was a major debate during the middle ages, and the issue remains fundamental in philosophy. Then, as now, one philosopher's solution is another's absurdity.

Logical studies largely stagnated due to the political disruptions of the times until Abelard. In each of his four logical works he commented on the Isagoge and refers to Porphyry frequently. Unfortunately in a most important work, the Dialectica, the first volumen and part of the second are lacking, where Porphyry was discussed and which contained very likely Abelard's most advanced views on universals. Out of Abelard's views on the copula grew the doctrine of suppositio terminorum or the doctrine of the different ways terms may stand for things. The theory of suppositio was much discussed in succeeding centuries. John of Salisbury's Metalogicon briefly discusses the predicables at the beginning of the third book, and he provides an interesting view of contemporary lecturers on Porphyry:

That which is written should be studied with sympathetic mildness, and not tortured on the rack, like a helpless prisoner, until it renders what it never received. One who withdraws what he never deposited, and harvests what he never sows, is far too severe and harsh a master, as also is one who forces (poor) Porphyry to cough up the opinions of all philosophers, and will not rest content until the latter's short treatise teaches everything that has ever been written.⁷

During the high middle ages a great deal of work was done in logic, but much of it is still unedited and unpublished so that conclusive judgments of its significance will continue to be reached as work goes on. From 1150 the Organon in its entirety was available to the West in Latin translation, and the courses in logic at mediaeval universities included the Organon, Isagoge, Boethius' De Divisionibus and De Differentiis Topicis, and Gilbert de la Porrée's Liber de Sex Principiis. The logic of the new works was called the ars nova and that of the old ars vetus. There were numerous contributors, among them William of Shyreswood, Peter of Spain, Robert Kilwardby, Raymond Lull, Walter Burleigh, William of Ockham, and Albert of Saxony. The Isagoge retained its stature throughout this period since the Organon and its imitators remained the basis of logical inquiry. William of Shyreswood's Introduction to Logic, for example, presents the predicables in a separate chapter and in Porphyry's order, a practice which was repeated in most authors.

From 1500 to 1850 there is little change in logical theory, though many textbooks were produced. Logic retained a place in the curriculum, but it no longer attracted as much attention as in the past. Formal logic received a sharp attack from Renaissance humanists who belittled Aristotle, scholasticism, and the “presumptions” of philosophers to special knowledge. Throughout all this, however, while some mediaeval logical doctrines pretty much disappeared, such as suppositio and consequentiae, the predicables and formal logic were taught. The major thrust of the period was discovery, and formal logic was seen as an ordering device, so that nothing new could come of it. For new approaches to logic we need only mention Francis Bacon, Ramus, Jungius, and Arnauld and Nicole of Port Royal. All of these attempts orient logic in a way that does not advance its formalization. Despite the work of Leibnitz in the 17th and 18th centuries, mathematics and logic were disjoined and not to meet again seriously until the 19th century.

The many complex developments of logic until the present cannot be detailed here. The great figures of recent times, men like Boole, Frege, Whitehead, Russell, Carnap, and others produced profound changes in our approach to logic, but logic, like philosophy itself, is seen differently at different times. Perhaps most germane to Porphyry and the controversies which emerged over universals is the recognition that the attempts to incorporate mathematics into logic or the reverse, which stand at the foundation of modern mathematical logic, gave rise to serious questions about the nature and reference of number and about the nature of meaning in general. The style and symbols of the discussion may have changed, but many of the familiar, ancient distinctions were employed again. Frege's Sinn and Bedeutung are an obvious example. The Isagoge presents a limited view of the possibilities of formalization, but many of its problems are also those of contemporary logic.

ISAGOGE AND METAPHYSICS

Although the attention paid to the Isagoge has been due to its connection with the history and development of logic, there is another side to its significance. Logic, even viewed as an organon, was closely connected to metaphysical reasoning, and one should not look upon the Isagoge as a simple piece of logical theory since its implications and applications go beyond formal principles of reasoning. The debates over universals were metaphysical, and the Aristotelian distinctions involved in the predicables were applied in the theory of knowledge and first philosophy and theology. To understand this little work, then, one must pay some attention to the relation of the Isagoge to metaphysics.

The problem of the reference of general terms undoubtedly arose during the mid-fifth century B.C. together with types of phenomenalism, rhetoric, grammar, theoretical mathematics, and scepticism. Historians of Greek philosophy do not speak of a “problem of universals,” and our age succumbs too easily, I think, to viewing the controversy as a mediaeval one. Western philosophy may be fruitfully viewed as a continuing debate over the scope of human understanding, and each major philosopher makes crucial commitments to a theory of human ideation and meaning. The 20th century might be called the Century of Meaning, in which a new term “meaning” replaces an old one, “idea,” in order to catch nuances and subtleties that seem obscured by the traditional language.

The problem of universals, or to what do general terms refer, has received varied answers in the past 2500 years, but the responses are usually classified under three terms: realism, conceptualism, and nominalism. The realist asserts the existence of the universal qua universal independent of the human mind; the conceptualist asserts that universals qua universal exist only in the human mind; and the nominalist that universals do not exist at all, not even in the human mind. As philosophers well known, classifying theorists according to these terms can be difficult and frequently frustrating, but the terminology persists and has its utility.

Up until the 16th century major Western thinkers were realists or conceptualists who wanted to claim knowledge of suprasensible existence in addition to natural knowledge. Nominalists were about but largely rejected and suppressed until the worldly humanism of the great Renaissance led to growing successes in the knowledge of the natural world. The generally nominalist response of modern philosophers after Francis Bacon was based on the conviction that natural knowledge did not imply realism, and probably not conceptualism, both of which were buttresses of a repressive theological-political system that attempted to control inquiry. Since the object of natural knowledge was a nature open to the immediate scrutiny of the senses and reasoning powers, there was no recognized need to posit an analogue to the Greek νοῦs and Latin intellectus that mysteriously grasped immaterial natures. With astronomy and physics leading the way, somewhat parallel to the 6th and 5th centuries B.C., philosophers attempted to found a sound epistemology and metaphysics of natural knowledge and either reject suprasensible reality or set it aside in its own realm where it could not contaminate the natural philosopher. An empirical sensationalism, a denial of a strong sense of intellectus or νοῦs, a substitution of hypothesis and probability for certitude, the emergence of time rather than eternity as the criterion of the real, and the adoption of a linear model of the world for a spherical one, led to a gradual transformation of Western thinking whose consequences are still being worked out. The development of these notions is not uniform, of course, but their course is clearly marked.

The change in metaphor is crucial for the history of metaphysics and logic, and so for the understanding of Porphyry's Isagoge. Metaphysics from Plato on had shown two opposite tendencies, to see reality (1) as temporal and so in a linear series, as Protagoras and the radical phenomenalism of τὸ πaν χίνηsιs eν in the Theaetetus (156a5), and (2) as eternal or non-temporal, in some ultimate way, and so complete and summed up like a sphere or circle. One might state the issue in this way: if existence is linear, the only point of reference for knowledge is the past by an accumulation of discrete data. A human mind may accumulate during its lifetime bits of information about preceding events in the series and by observing similarities and differences hypothesize that coming events will accord with developed rules. Reference, then, is limited to the past. If existence is spherical, it is at all times summed up or totaled. Any segment of the temporal line can be referred to the Whole and understood. Instead of a linear series one has a set of whole-part relations. Implicit in the time-series is a pattern or λόγοs that expresses the eternal in time at a given moment. Some doctrine of participation or analogy must account for the relation between the partiality of time and the wholeness of eternity. The whole must be immanent in the parts or else there are no parts, only independent segments. The eternal metaphysical scheme dominated Western thinking until the 16th century when serious changes came about, coming to full flower in the 19th century, a process which George Boas has called the “Acceptance of Time.”⁸ Aristotle's logic, treated as a class logic, rests on the spherical metaphor of whole and part. The Tree of Porphyry provides a striking example. In the Isagoge the three terms “individual,” “singular,” and “particular,” reflect different approaches to space-time objects, and an adequate grasp of these nuances of metaphor is necessary for a firm grasp of the issues as seen by the ancients. There are several notes to the translation which attempt to clarify these distinctions.

Porphyry's introduction, then, is important to us as a document in the history of metaphysics and the theory of knowledge, and perhaps more so than as a logical one. Its influence is due to the logical tradition of Aristotle's Organon, but its significance lies in the connection of that tradition to metaphysical and epistemological issues.

COMMENTARIES OF BOETHIUS

These two commentaries merit special, though brief, mention because of their influence. Evidence indicates that besides the Greek commentary of Ammonius (d. 480) other commentaries on the Isagoge had preceded. It is thought that Boethius in his own work used Ammonius or Ammonius' source. The first commentary is less well known, shorter (2 books), written in the form of a colloquy between Boethius as teacher and Fabius as student. The structure is patterned after Porphyry's own extant commentary on the Categories, Expositio Per Interrogationem et Responsionem, CAG IV. Although Boethius uses the translation of Victorinus as the basis of his work, he paraphrases and sometimes corrects his predecessor's version. The second commentary is a straightforward analysis of Porphyry in five books based on Boethius' own translation.

Of some importance in the second work is Boethius' attempt at a solution to the problems posed as the deeper questions in the opening section of the Isagoge. Boethius professes to follow Alexander of Aphrodisias; and, as is generally agreed, the solution is more a statement of an Aristotelian position than anything else, since grave questions remain untouched. Boethius asserts that the mind collects a similitudo or likeness (“A likeness is nothing else but a kind of unity of quality.” E.S. p. 228, 20) from singular things and thinks a universal. Thus, generic and specific contents “subsist in connection with sensible things but are understood without bodies.” E.S. p. 166, 22-23. What is involved epistemologically and metaphysically in collection is untreated. There is no reason to regard this solution as that of Boethius since he consciously follows a Peripatetic line of argument and the commentary treats of an introduction to Aristotle: “therefore, we have followed Aristotle's opinion quite carefully, not because we approved of it especially, but because our book is written with Aristotle's book in mind, his Praedicamenta (Categories).” E.S. p. 167, 17-20. In the first commentary Boethius had asserted the existence of the predicables and predicaments “which are put into things and in some way are united with them” otherwise there would be no point in discussing them. He did not, however, introduce the notions of similitudo and collection. Also, in the second commentary a Platonic view of the predicables occasionally emerges, i.e., “therefore, species also subsist before individuals.” P. 316, 22-23. Both commentaries can be consulted with profit, especially the introductory portions, although the later sections can be helpful in lesser problems of interpretation.

Notes

1. Cambridge History of Later Greek and Early Medieval Philosophy, ed. A. H. Armstrong, Cambridge U. Press, 1967, p. 281.

2. For the historical importance of the Isagoge consult A History of Formal Logic, I. M. Bochenski, tr. and ed. by Ivo Thomas, U. of Notre Dame Press, 1961; W. and M. Kneale, The Development of Logic, Clarendon Press, Oxford, 1962; the Cambridge History of Later Greek and Early Medieval Philosophy, ed. A. H. Armstrong; Vie de Porphyre, J. Bidez, Ghent, 1913, Georg Olms, Hildesheim, 1964; The Logic of William of Ockham, E. A. Moody, N.Y., Russell and Russell, 1935, repr. 1965. See also the brief mention of R. Walzer, “Porphyry in the Arabic Tradition,” Porphyre, Entretiens sur L'Antiquité Classique, Tome XII, Vandœuvres-Genève, 1965.

3. Aristotle's Topics 101b 17-24, 139a 29-30, E. S. Forster, Loeb Classical Library. E. A. Moody finds a “porphyrean interpretation of Aristotle” in the addition of species to the predicables and in the profound questions raised at the beginning of the Isagoge. Logic becomes muddled with metaphysics; Aristotelianism encumbered with a Platonic interpretation. The influence of the Isagoge on medieval speculation, then, was invidious. Sir David Ross also regards the addition of species as a serious error: “… Aristotle's classification of … predicables … Porphyry later muddled hopelessly by reckoning species as a fifth predicable. The place of species in Aristotle's account is not as one of the predicables but as the subject: …” Aristotle, p. 57. Moody seems to err in supposing that Porphyry “insisted that Aristotle's analysis of modes of significance could only be understood in the light of his analysis of the ways in which one term can be related to another in predication.” The Logic of William of Ockham, p. 67. Moody's book is suggestive and subtle, well worth serious reading, but here he seems excessively critical. The composition of the Isagoge appears quite accidental, and the treatise does not contain any polemic. If such a charge is to be made, it should be lodged against Boethius who conveys this impression. For example, “Aristotle can not be understood unless an introduction is written as a kind of bridge to him, …” E.P. I, 2, p. 5, 12-13. Moody seems to infer a claim of philosophical priority from a pedagogical technique. Porphyry's inclusion of species is no doubt an error, but for my part, Aristotle's metaphysics of the individual nature only makes sense against the background of whole-part relations implicit in final causality, and the metaphysical grounding of the individual is weak regardless of Aristotle's intent. If anything, Porphyry was well aware of this weakness and exposed it en passant in the Isagoge. One might well argue that Porphyry's error served to call attention to ambiguities in Aristotle's metaphysics and to force consideration of Platonic participation within Aristotelian philosophy. See A. C. Lloyd's “Neoplatonic Logic and Aristotelian Logic,” Phronesis 1, 2, p. 155 ff., Van Gorcum, Assen, Netherlands.

4. For the importance of Victorinus: “En matière de logique, Boèce n'a fait que traduire ou paraphraser un recueil de textes et de commentaires détachés avant lui de l'œuvre de Porphyre et déjà devenus classiques, grâce à l'enseignement de Marius Victorinus. C'est celui-ci peut-être, autant sinon plus que Boèce, qui donna aux manuels de Porphyre la forme latine sous laquelle ils devaient se vulgariser et qui eut le mérite de créer la terminologie dont la logique formelle … l'art de penser de Port-Royal … continue à se servir pour discipliner nos esprits.” J. Bidez, “Boèce et Porphyre,” Revue Belge de Philologie et d'Histoire, t. l, 1923, p. 200.

5. Aristotle's Categories and De Interpretatione, tr. by J. L. Ackrill, Clarendon Press, Oxford, 1963, n. la l, p. 71.

6. The Development of Logic, W. and M. Kneale, p. 176.

7. The Metalogicon of John of Salisbury, tr. by D. D. McGary, U.C. Press, 1955, p. 148. See also pp. 110-111. In general one ought to consult this work for the flavor of debates and intellectual life of the 12th century. For a summary of then current views of universals, see pp. 111-116.

8. Dominant Themes of Modern Philosophy, George Boas, The Ronald Press Co., New York, 1957, p. 612.