Medieval Science, Technology and Medicine

Dioscorides

Dioscorides Pedanius is known as the author of De mate-ria medica (MM), the most influential treatise of classical antiquity in Greek on the natural substances used for the preparation of medicines. Identified as Pedanios Dioskorides Anazarbeus in Byzantine manuscripts, Dioscorides probably lived during the first century C.E., and was born in Anazarba (Cilicia, Asia Minor). Thought by modern scholars to have received his medical education in Pergamon and Alexandria (or, according to some research, in Tarsus), Dioscorides is thought to have then become a physician to the Roman army under the emperors Claudius (41–54 C.E.) or Nero (54–68 C.E.). During his extensive travels throughout the Empire, especially in the Middle East, Dioscorides would have been able to gain firsthand experence of many of the products he analyzed in MM.

MM, often considered a herbal, deals with all three natural kingdoms: plant, mineral, and animal. It describes all the natural substances known to Dioscorides that were used as primary ingredients for medicines (i.e., drugs), and constitutes an encyclopedia on the topic. A chapter is devoted to each drug. MM contains just over one thousand chapters and features 794 plants, 104 animals, and 105 minerals. Most of the chapters contain the following information: (a) The most common name of the drug and its possible synonyms; (b) A description of the natural element producing the drug (for a vegetal drug, the whole plant); (c) The part used as a drug, possibly with its preparation; (d) The therapeutic properties of the drug; (e) The disease(s) for which the drug was used, including the preparation and administration of the medicine; (f) When appropriate, the falsifications and methods of authentication of the drug; and (g) Other uses of the drug, such as in cosmetics, veterinary medicine, or handicraft.

In several Byzantine manuscripts, the text of MM is accompanied by illustrations of plants, animals, and minerals whose authenticity and style are still debated: were they in Dioscorides’ originals or are they subsequent additions? Whatever their origin, were they originally realistic and became schematic over time due to successive copies? No definitive argument has been provided so far for either theory.

In its canonic form, MM is composed of five books of almost equal length, each of which supposedly deals with a specific topic. This division is thought to have been imposed by the length of the rolls of papyrus which were the medium of book production in Dioscorides’ time. Whatever the truth of that, drugs are grouped so as to constitute major classes (e.g., perfumed plants, oil and perfumed oils, trees, fruit trees, animals, and cereals) and, within each class, groups with a specific therapeutic action. Within these groups, drugs are listed in order of the extent to which they demonstrate the degree of activity that is common to the group. Drug classes, in turn, are ordered so that their supposed therapeutic properties shift from hot and drying at the beginning of MM to cold and humidifying at the end. Differences between classes are gradual and constitute a proper scala naturae, each major step of which corresponds to a period of the mythological history of the cosmos (the five ages of the world and humankind), characterized by a gradual reduction of positive qualities.

Some MM manuscripts contain a treatise On simple drugs (in Greek) that lists drugs by diseases and is of uncertain authenticity; other manuscripts have transmitted under Dioscorides’ name two treatises, On poisons and On venomous animals, which were associated with MM before the ninth century. Although they contain material dating back most probably to Dioscorides’ period, they do not seem to be authentic, but were added to MM over time (maybe in two steps), as they supplement it.

Byzantium and the East

MM had a truly exceptional history from antiquity to the Renaissance. It was spread very soon across the entire Mediterranean world, from Egypt to Constantinople, from Syria to Rome. Its original structure seems to have been modified as early as the fourth century C.E. if not before: the new recension organized the text in alphabetical order by drug name. In On simple drugs, mixtures, and properties, *Galen, who relied on MM for the description of drugs, already used this order, as did also the authors of early Byzantine medical encyclopedias, Oribasius (fourth century), Aetius (sixth century), and Paul of Ægina (seventh century). In these encyclopedias, MM text is associated in different ways with Galen’s treatise on simple drugs.

A certain number of MM chapters dealing with plants were extracted from this alphabetical version to form an alphabetical herbal. This new recension—the oldest known manuscript of which is the richly illustrated Vindobonensis medicus graecus 1, dated about 513, now preserved in Vienna (Austria)—necessarily predates such a codex. Its origin, which has never been accounted for, might be the result of an attempt to reduce the number of drugs in MM from the original thousand to about three hundred. Eastern drugs were not included in this herbal. Before the ninth century, the chapters of MM not included in the herbal were taken again from MM full text, divided into four groups (oils, animals, trees, and minerals), and added to the herbal so as to form again a five-book version of MM. In each of these books of a new kind, chapters were sequenced according to the alphabetic order of drug names. Oriental drugs seem not to have been reintroduced into this new version until the mid-eleventh century codex Megistis Lavras S 75 (Mount Athos, Greece).

The MM Greek text was translated into Syriac during the sixth century, and into Arabic during the ninth. *Hunayn ibn Ishaq (808–873), working in Baghdad in collaboration with Istifan ibn Basil, translated it first from Syriac and then a second time from Greek. Characteristically, many Greek names of drugs were not translated, but merely transliterated. Even though the translators stated that they did not know the exact translation of such terms, they could also have proceeded in this way to keep apparent the structure of MM, which relies in many cases on the similarity of drug names. Hunayn’s translations were further revised, if not replaced, by later versions made at the court of eastern Arabic princes. Several Arabic copies of MM (whatever the version) contain polychromatic representations of plants and other materia medica, some in a highly stylized fashion. MM provided a basis for many new Arabic herbals and materia medica treatises.

After the Latin occupation (1204–1261) of Constantinople, the most important extant manuscripts of MM of the earlier periods seem to have been gathered all together in the same place in the capital, possibly the Katholikon Mouseion, that is, the school adjacent to the hospital of the king of Serbia Milutin (the so-called Xenodocheion tou Krale), in the Petra area of Constantinople. Damaged codices were restored and their texts collated to produce a revised edition (the so-called Byzantine recension), that is, a medically updated version. The illustrations were also revised. This new text replaced earlier versions and was widely spread, both in Constantinople and in the West in the Renaissance.

The West

Known in Rome at least at Galen’s period, the MM Greek text was not as extensively revised in Italy during subsequent periods as it was in Byzantium. At some time after the ninth century C.E., one or more illustrated codices of MM could have arrived in Italy from Syria-Palestine and were copied.

A Latin translation supposedly referred to by Cassiodorus (c. 490–c. 583) was made, maybe during the sixth century, in North Africa or southern Europe. Its earliest copy is the Dioscorides longobardus, (manuscript Clm 337 of the Bayerische Staatsbibliothek in Munich). This document, written in the typical script of Benevento (Italy), has been recently attributed to the area of Naples and the tenth century, and is illustrated in simple color.

Contacts between East and West started before the translation enterprise whose beginning is traditionally attributed to *Constantine the African (d. after 1085), in southern Italy and southern Spain. Córdoba was in contact with Constantinople during the tenth century: an illustrated copy of the MM in Greek was sent to the emir as a present by the emperor. No new translation was made (contrary to what is often asserted in literature), but Hunayn’s translation, which had arrived earlier, was revised and corrected by means of this Greek manuscript.

While it is generally affirmed that Western residents of Constantinople did not interact with local scientists between the end of the Fourth Crusade (1204) and 1261, a manuscript herbal (Copenhagen, Kongelige Bibliotek, Thot 190) contains plant representations similar to those of Greek manuscripts that were at the Katholikon Mouseion during the fourteenth century. Later, *Pietro d’Abano (1257–c. 1315), who traveled to Constantinople shortly after the end of the Latin Kingdom, referred to an alphabetical recension of the MM in his pharmacological work. He might have seen the Vindobonensis manuscript and, in any case, he seems to have taken note of variant readings from the herbal and compared them to those of the five-book recension.

A copy of the Byzantine five-book recension made during the early fourteenth century in Constantinople seems to have been in the milieu of Manouel Chrysoloras (c. 1350–1415), a Byzantine scholar who emigrated to Florence. Further on, this copy (which is now manuscript Florentinus Laurentianus 74.23) arrived in the collection gathered by Lorenzo de Medici (1449–1492), and was borrowed by Angelo Poliziano (1454–1494). Later on, such collectors as Cardinal Bessarion and Isidorus, Cardinal of Kiev (1380/90–1463), had copies of MM, which they brought to Italy and donated to the Republic of Venice and the Vatican Library respectively.

After the Fall of Constantinople (1453), the MM Greek text reached Italy through two main channels. One route was via Crete, where Michael Apostoles (c. 1420–1474 or 1486), a protégé of the Greek cardinal Bessarion (1400–1472), had created a scriptorium. His collaborators seem to have reproduced only an alphabetic version (which is not necessarily the one supposedly made in antiquity). The other route was across the Adriatic and through Venice, thanks to the manuscript now preserved at the Bibliothèque Nationale de France (Paris) under the shelf-mark graecus 2183, which contained the Byzantine recension and was used as a model for several copies, thus widely spreading this version of MM. Collectors and scholars such as Pico della Mirandola (1463–1494), Giorgio Valla (c. 1487–1500), Ermolao Barbaro (1453–1493), and Nicolao Leoniceno (1428–1524) had one or more copies of the MM.

MM Latin text commented on by Pietro d’Abano was printed as early as 1478 at Colle (Tuscany, Italy). Shortly after, Ermolao Barbaro wrote a Latin translation with commentary, which was not published before 1516, however. The MM Greek text was printed in 1499 by Aldo Manuzio (1449–c. 1515), on the basis of a copy of manuscript Parisinus graecus 2183, that is, the Byzantine recension. The Aldine edition could have been prepared by Nicolao Leoniceno in order to demonstrate the validity of the thesis that he first put forth in his booklet De Plinii aliorumque in medicina erroribus (Ferrara, 1492), according to which Greek scientific texts of classical antiquity (particularly MM) were superior to Pliny’s Natural History and the medieval Latin translations of Arabic authors. Whatever the case, both the De Plinii and the 1499 Greek edition of MM closed the medieval period of MM history.

Bibliography

Primary Sources

Dioscorides: Pedanii Dioscuridis Anazarbei. De materia medica libri quinque. Edidit M. Wellmann. 3 vols. Berlin: Weidmann, 1906–1914 (reprinted 1958 and 1999).

Gunther, Robert T. The Greek herbal of Dioscorides. Illustrated by a Byzantine A.D. 512, Englished by John Goodyer A.D. 1655, edited and first printed A.D. 1933. New York: Oxford University Press, 1934.

Secondary Sources

Aufmesser, Max. Etymologische und wortgeschichtliche Erläuterungen zu De materia medica des Pedanius Dioscurides Anazarbeus. Hildesheim: Olms-Weidmann, 2000.

Riddle, John M. “Dioscorides.” In Catalogus translationum et commentariorum: Mediaeval and Renaissance Latin translations and commentaries 4. Edited by F.E. Cranz and P.O. Kristeller. Washington, D.C.: Catholic University of America Press, 1980: 1–143.

———. Dioscorides on Pharmacy and Medicine. Austin: University of Texas Press, 1985.

Sadek, Mahmoud M. The Arabic Materia Medica of Dioscorides. St-Jean-Chrysostome: Les Editions du Sphinx, 1983.

Scarborough, John and V. Nutton. The Preface of Dioscorides’ Materia Medica: introduction, translation, and commentary. Transactions and studies of the College of Physicians of Philadelphia (1982) 5.4: 187–227.

Touwaide Alain. L’authenticité et l’origine des deux traités de toxicologie attribués à Dioscoride. Janus (1983) 70: 1–53.

———. “Les deux traités de toxicologie attribués à Dioscoride. Tradition manuscrite, établissement du texte et critique d’authenticité.” In Tradizione e ecdotica dei testi medici tardoantichi e bizantini. Edited by A. Garyz. Naples: M. D’Auria, 1992: 291–339.

———. “Le Traité de matière médicale de Dioscoride en Italie depuis la fin de l’Empire romain jusqu’aux débuts de l’école de Salerne. Essai de synthèse.” In From Epidaurus to Salerno. Edited by A. Krug. Rixensart: PACT Belgium, 1992: 275–305.

———. “La botanique entre science et culture au Ier siècle de notre ère.” In Geschichte der Mathematik und der Naturwissenschaften in der Antike I: Biologie. Edited by G. Wöhrle. Stuttgart: Franz Steiner, 1999: 219–252.

———. “Loquantur ipsi ut velint … modo quis serpens sit tirus … non ignorent: Leoniceno’s contribution to Renaissance epistemological approach to scientific lexicology.” In Medical latin from the Late Middle Ages to the Eighteenth century. Edited by W. Bracker, and H. Deumes. Brussels: Academy of Medicine, 2000: 151-173.

Wellmann, Max. Die Schrift des Dioskurides peri aplôn farmakôn. Ein Beitrag zur Geschichte der Medizin. Berlin: Weidmann, 1914.

ALAIN TOUWAIDE

Duns Scotus, Johannes

It is usually accepted that Johannes (John) Duns Scotus was born in late 1265 or early 1266 in the small Scottish village of Duns just north of the border with England. He joined the Franciscan order, in which his distinguished scientific predecessors included *Roger Bacon and *John Pecham. He was studying in Oxford in 1291, during which time he began the composition of important sets of questions on the logical and metaphysical works of Aristotle, as well as a draft—the Lectura—of his major theological work, his Oxford commentary on *Peter Lombard’s Sentences. The revision of this work—the Ordinatio—was under way by 1300. In about 1301 Scotus was sent to Paris to continue his theological studies, where he lectured for a second time on the Sentences. The work survives as a set of examined student notes—the Reportatio—and Scotus became regent master (professor) in theology at Paris in 1305, where he presided over one set of quodlibetal disputations. In 1307 he was moved to the Franciscan house of studies in Cologne, where he died on November 8, 1308, with most of his works extant only in more or less complete drafts.

Scotus’s main philosophical achievements lay in the areas of *metaphysics and action theory. He attempted to solve the problem of the individuation by positing haecceities—thisnesses: non-qualitative features of substances, proper to each substance. His theory of transcendental concepts, reducing all knowledge to a set of simple, non-overlapping, non-definable concepts, is ancestor of the rationalist philosophy of figures such as was later developed by Leibniz. Scotus was the first to formulate a notion of logical possibility, conceiving the possible as the non-contradictory, irrespective of its real existence at some time or another (and thus independent of physical possibility). In line with this, he was the first to attempt a philosophical defense of human free will as a real power to choose different courses of action in exactly the same circumstances, something required by the *Condemnation of 1277.

The Nature of Science

Like all practitioners of *Scholasticism in the thirteenth and fourteenth centuries, Scotus was heavily indebted to the recently recovered thought of Aristotle. According to Aristotle, a science or *scientia is an explanatory deductive system deriving theorems from necessarily true axioms. Aristotle holds that we can posit such axioms if required to explain some empirical fact. Scotus adds a probabilistic element that brings him somewhat closer to modern views of induction. He believes that through experiment (that is, experience), we know that such-and-such an event follows such-and-such a substance for the most part; we can infer from this that the event is caused by the substance, since causes of the same type by definition produce effects of the same type.

Duns Scotus. Unattributed engraving (1584) after André Thevet (c. 1516?–1592). (Mary Evans Picture Library)

Unsurprisingly, Scotus follows Aristotle’s division of the theoretical sciences, in Metaphysics bk 6, ch. 1, into mathematics, natural philosophy or physics, and first philosophy or metaphysics. Scotus accepts a version of Aristotle’s *hylomorphism, according to which bodies are composites of matter and form. He holds that physics studies bodies insofar as they have “form, which is the principle of determinate operation, motion, and rest… which can be known by the way of sense.” Scotus is happy to use mathematical tools in his physics, and like many medieval authors is perhaps more aware than Aristotle of the fundamentally mathematical structure of empirical reality.

Natural Philosophy

Scotus is remembered not so much for his scientific achievements as for other achievements in philosophy and theology; perhaps the reason for this is merely the extent of his achievements in these last two areas, for he makes some important contributions in natural philosophy. There is, however, little in his writings that implies a particular scientific relation to earlier Franciscan tradition.

One of Scotus’s most important innovations is the rejection of a fundamental principle of Aristotelian physics, that self-motion is impossible, a principle that undergirds the Aristotelian argument for a first mover. Scotus reasons that motion requires the notions of act and potency: an active power to cause, and a passive potency to be caused (to be made to exist in a certain state). Scotus argues that there is no reason why one and the same substance could not possess both the active power and the passive capacity, and thus change itself.

The version of hylomorphism that Scotus accepts differs from Aristotle’s in various ways. One, which he inherited from his Franciscan (and other) predecessors is that, in order to explain the identity of a living body with a dead one it is necessary to posit a bodily form, giving the body its basic structure, and another form, the soul, giving the body the microstructure that allows it to live. Scotus also concludes that matter must have some reality in itself, such that it could exist without any form whatsoever, in order for matter to be the substrate of Aristotelian substantial change, the thing that “exists now in a different way than before.” If matter lacked any reality in itself, then it would be impossible for it to remain constant over a change.

The Condemnation of 1277 allowed for the possibility both of an intracosmic vacuum and of extracosmic space. Scotus follows these anti-Aristotelian lines of thought, arguing that a notion akin to that of absolute space is required to deal with the Aristotelian problem of an immobile body surrounded by moving bodies, and that such a notion can be used to give an account of a vacuum and extracosmic space too. (Extracosmic space does not exist; it would, however, if God were to create something at a distance from this universe.)

Scotus follows Aristotle in wanting to give a nonatomistic account of motion, and thus of space and time, but he adds some important arguments of his own. Like Aristotle, he holds that extension requires divisibility, and that however far the process of division is carried, there is always more that can be done. He notes that the divisibility of space (or time) at any point does not entail divisibility at every point (as argued by an unnamed opponent), and thus that infinite divisibility does not entail composition from infinitely many points. And he makes use of two geometrical arguments to show that an extended magnitude cannot be composed of a finite number of unextended points. The first argues that, on the assumption of composition from such points, it would be possible for a line drawn from the centre of two concentric circles not to bisect both circles, and the second, derived from Bacon and (remotely) from *al-Ghazali, reasons from the incommensurability of the side and diagonal of a square. Scotus makes use of a version of his first argument to show that an extended magnitude could not be composed of a finite number of extended minimum particles either.

Scotus uses his anti-atomistic insights to develop an important new theory of the *latitude of forms. According to Scotus, kinds or species of qualities admit of degrees. Increases and decreases are explained by the addition and subtraction of new “parts” of the quality, such that lower degrees persist and are contained in higher degrees. Degrees of a quality thus admit of quantitative analysis in terms of more or less (of the quality). Against the opposing view that change in quality requires the production and destruction of complete qualities, Scotus argues that such a theory could not explain the continuity of a gradual change, requiring (impossibly) the production and destruction of infinitely many qualities in finite time. Seeing qualities in this quantitative way opened the way for the quantification of velocity (seen as a quality of motion), and thus for the formulation of the mean-speed theorem proposed by *Richard Swineshead and *William of Heytesbury.

Religion and Science

Scotus’s theology has a marked influence on his scientific theories, although he is careful always to find non-theological arguments in favor of his scientific theories too. The context of the discussion of the latitude of forms is an account of increases (and decreases) in grace, conceived on the analogy of an Aristotelian quality. And Scotus makes use of his theory to give an account of the infinite perfections of God: God’s perfections are like infinite degrees of qualities. This means, in turn, that in at least one important context, Scotus rejects Aristotle’s denial of an actual infinity. Scotus supposes that God’s infinite perfection can be pictured on the analogy of an actually infinite magnitude (just as the degrees of a quality are understood on the analogy of an extended quantity). Scotus’s account of the plurality of forms is formulated in part to deal with the problem of the identity of Christ’s dead body in the tomb, something arising from the 1277 condemnation. Moreover, according to Scotus, the doctrine of transubstantiation entails the reality of quantity distinct from substance, that place is distinct from extension, and that substances are fundamentally unknowable, since it is impossible to know that God has not transubstantiated the whole universe into Himself.

Bibliography

Primary Sources

Joannes Duns Scotus. Opera Omnia. 12 vols. Edited by L. Wadding. Lyon, 1639.

———. Opera Omnia. Edited by C. Baliç. Vatican City: Vatican Polyglot Press, 1950–.

———. God and Creatures: The Quodlibetal Questions. Edited by Allan B. Wolter and Felix Alluntis. Princeton: Princeton University Press, 1975.

———. Philosophical Writings: A Selection. Edited by Allan B. Wolter. Indianapolis: Hackett, 1987.

———. Opera Philosophica. Edited by G. Etzkorn. St Bonaventure, NY: The Franciscan Institute, 1997–.

Secondary Sources

Cross, Richard. The Physics of Duns Scotus: The Scientific Context of a Theological Vision. Oxford: Clarendon Press, 1998.

Duhem, Pierre. Medieval Cosmology: Theories of Infinity, Place, Time, Void, and the Plurality of Worlds. Chicago: University of Chicago Press, 1985.

Grant, Edward. Much Ado about Nothing: Theories of Space and Vacuum from the Middle Ages to the Scientific Revolution. New York: Cambridge University Press, 1981.

King, Peter. “Duns Scotus on the Reality of Self-Change.” In Self-Motion from Aristotle to Newton. Edited by Mary Louise Gill and James G. Lennox. Princeton: Princeton University Press, 1994.

Lewis, Neil. “Space and Time.” In The Cambridge Companion to Duns Scotus. Edited by Thomas Williams. New York: Cambridge University Press, 2003.

RICHARD CROSS

D

Despars, Jacques

Bibliography

Primary Source

Secondary Sources

Dioscorides

Byzantium and the East

The West

Bibliography

Primary Sources

Secondary Sources

Duns Scotus, Johannes

The Nature of Science

Natural Philosophy

Religion and Science

Bibliography

Primary Sources

Secondary Sources