Tuesday, September 25, 2007
Ibn al-Nafis (1210-1288)
H.E. PROF. EKMELEDDİN İHSANOĞLU
Secretary General of the Organization of the Islamic conference on the occasion of the presentation of the title of Doctorate (honoris causa) By the university of Padua, Padua, Italy, 11 December 2006
Note: See underlined section below for direct reference to al-Nafis
I am filled with pride and pleasure as I receive the title of “dr. honoris causa” conferred on me by the University of Padua, a most prestigious institution which, for centuries, has played a significant role in the advancement of learning. As an academician committed to the development of knowledge in search of truth, and the betterment of science and scholarship, I am deeply honoured by this prestigious title. I receive it in consideration of all the historical experiences and the historical realities embodied within these splendid premises as well as all the universal values sought for the well-being of humanity.
The evolution of world politics since the last decade of 20th century and several substantial events witnessed during this period have modified communities’ outlooks towards each other. They sometimes modified our whole perception of global issues and generated new themes, trends and concerns in international relations. In this new period one of the most frequently referred themes is certainly that of inter-cultural relations, in particular the relations between the Muslim world and the Western world. While they indirectly affect economic relations, trade and business, these relations directly involve and spontaneously engage both political activity on one hand, and academic inquiry on the other. The reason for directing attention to the subject of inter-cultural relations is certainly not only academic. Explanations on the present order have been diverse, reflecting a variety of approaches. In the face of revived and renewed manifestations of misunderstandings and suspicions among nations, cultures and civilizations, we as scholars and perhaps only us have the means to show, objectively and unequivocally, that any effort to activate such negative feelings is bound to fail. In this endeavour our tool is no doubt, the results we can draw from the history of one of the most remarkable joint achievements of mankind, the history of science. The history of civilization, with or without an s at the end, is an eternal river. As Fernand Braudel states in his book A History of the Civilisations, the history of mankind is a history of the exchanges between civilisations. In this interactive process, every civilisation preserves its distinct characteristics, adds its own cultural elements to borrowed elements, and then passes it on to others. This history offers an immense and fertile field of study from where one can infer evidence of the innumerable common elements inherent to the various cultures and civilisations. Highlighting these factors as the substrata of a shared legacy of mankind can bring an element of rapprochement into a world that is fraught with controversies and conflicts. It can help to combat stereotypes and misinformation, in particular those related to Islam and the Muslim world. Therefore, it is both a moral and an academic duty to create consciousness in public opinion on the common heritage of mankind. An objective history of science is most effective to this aim.
Speaking of history of science at this particular venue is highly fitting and certainly not mere coincidence. One of the first universities of the world, established in 1222 within the same drive together with those of Bologna, Paris, Montpellier, the University of Padua actively participated in the Renaissance and the Enlightenment; it housed brilliant figures: here Copernicus, Galileo, Vaselius and Harvey were among the illustrious teachers and students. In the continuum of production and diffusion of science vertically down through the ages as well as within each major period of scientific activity, one of the main determinants of the degree of success is no doubt the institutional set up. Universities directly affect the course of scientific development not only as agents of diffusion of knowledge but also as builders of scientific mentality and cultural environment. In this respect the University of Padua has played a distinct role as one of the major crucibles of transmission of knowledge where translations from Arabic of the commentaries and innovative works of Muslim scientists and philosophers, based on Greek science and philosophy, were received, and disseminated throughout the Renaissance centuries. In this sense, the history of the transmission of science in the hands of this institution has been a most significant example of inter-cultural exchanges, and I will also say, civilisational dialogue, in History.
Science from Islam into Europe
The civilization of Islam expanded into Europe starting from the 8th century through the Muslim rule in Spain and asserted its presence in the continent in the 9th. From then on, cultural contacts developed between the Muslims and the Europeans in addition to commercial exchanges. The subsequent centuries were marked by moments of togetherness and interaction where Christians, Muslims and Jews coexisted fruitfully in Europe and elsewhere. The period of the Muslim rule in Spain, exchanges of knowledge during and after this period and prior to the European Renaissance, and subsequently the late Ottoman period, represent such historical moments of fruitful coexistence.
The former, the great influx of new knowledge into the Latin world between 1100 and 1200 which came partly through Italy and Sicily, but mainly through Spain, transformed learning in its essence. The addition of new logic, the new mathematics, and the new astronomy to the older Latin trivium and quadrivium are but some of the many features of the world of learning that now tied the two intellectual worlds together. Hence learning in European universities was deeply influenced by translated Islamic learning. The manuscripts of Muslim authors were comparatively abundant and many “compendia” containing the so-called “Arabist doctrines” were issued under the control of the universities of Bologna, Oxford and Padua. Studies on Bodleian library and other collections at Oxford University revealed that Arabic manuscripts and their Latin translation influenced the development of learning at the early stages of this university. Gerard Langbaine (1609-1658), the keeper of the archives of the university, compiled material from the Bodleian and other libraries in Oxford which illustrate the history of interest in Arabic sources. In one of his notebooks, he starts with Adelard’s transcribing the opening of his Natural Questions, underlining Adelard’s mention of Saraceni and Studia Arabum, then refers to three translations from Arabic made by him; then Plato of Tivoli’s translation of al-Battani’s astronomical tables; he then quotes portions of the dossier that Roger Bacon sent to Pope Clement IV that are relevant to the learning of Arabic, and he goes on to transcribe the introduction of Daniel of Morle’s Philosophia, in which Daniel describes his visit to Toledo. There is also a powerful link between Islamic works and Oxford University, via Alfred of Sareshel’s translations, which helped shape the teaching of later masters, such as Adam of Buckfield, Roger Bacon, and Henry of Renham, and also the Avicennist John Blund, who was teaching at the faculty of arts from around 1200 to 1209, before having to leave as the university was closed down because of riots; John Blund went to lay down the foundation of Cambridge. Although he seemingly praises Aristotle, and the fact that the “Arabs” in quote had recently handed Aristotle’s science over to the Latin, Blund in his surviving work, De anima, relies mainly on Al-Kindi, Ibn Sina, and Al-Farabi. In 1200, at the time Blund, and possibly Alfred of Sareshel were teaching at Oxford, Grosseteste was also teaching the arts there, before he was appointed the first Chancellor his personality and scholarship eventually making Oxford a rival to Paris.
I wish to mention as well another European university of later date of establishment but relevant to what I am trying to say here; this is the University of Cracow, which was founded towards 1405. This university had one of the early chairs of astronomy in Central Europe where Copernicus studied mathematics and astronomy. It was towards 1450 that studies of astronomy at Cracow blossomed thanks mainly to the contribution of Martin Krol, who in his collection owned the works of Muslim astronomers, such as the commentaries on Ptolemy’s Almagest by Ali ibn Ridwan, the same author’s comment on Ptolemy’s centiloquim, the De Plaviis of al-Kindi, the Liber introductorins of al-Qubaysi and many other works. Isaiueh and Korolec in their competent studies showed us the effect of Islamic astronomy texts on the education at Cracow University. Korolec goes on to make an extremely useful list of the Islamic manuscripts that served at the teaching at Cracow. So it is no longer a surprise that Copernicus had solid background knowledge of the achievements of the astronomers of Islam.
Copernicus Certainly in this short talk I cannot address all changes produced in the Latin West by successive translations of Arabic works nor cite all the translations made from Arabic or all the medieval authors who may have been influenced by them. Neither can I refer to the important developments in trigonometry and particularly spherical trigonometry, the making of instruments and the precision in computation, nor the astronomical tables or catalogues of stars. I would rather dwell on one or two elements which I consider of utmost importance as I do speak here in Padua where Copernicus was once a student.
What I am trying to show here is how we can understand, in the light of modern scholarship, the way Nicholas Copernicus could have been influenced by the developments made by Muslim astronomers though we know he did not learn Arabic, the language of scientific literature in the medieval world. Perhaps the best way to do that is to see to which extent the academic milieu in his time was conducive to such influence and to see the resemblance and correspondence between his knowledge, propositions and discoveries and those of his Muslim predecessors. As we try to portray these features, two questions remain to be answered. What were the channels of influence and how did he personally make it?
The influence of Islamic astronomy on the Copernican system One of the main challenges of the Islamic astronomers and natural philosophers was to solve the physical and mathematical inconsistencies in the Ptolemaic system of the world. While the Aristotelian foundations of the geocentric world demanded uniform circular motions around the centre of the world, observational and mathematical considerations caused Ptolemy to define a point, called equant, which was not coinciding with the centre of the world (not with the centre of eccentric) but it was with respect to that point that a typical planet performed uniform motion. It was Ibn al-Haytham who had a strong influence on the development of the new non-Ptolemaic astronomical theories from the eleventh century onwards. These efforts created an astronomical system having a physical reality which improved on Ptolemy’s results by reaching a greater coherence – models without equant, for example - and, sometimes, such as in Ibn al-Shatir, a better agreement between geometrical models and observation - even in those cases in which Ptolemy’s models failed – was reached by a group of astronomers who worked in the Maragha Observatory and thus, the denomination of “Maragha School” has often been applied to them. The first formulation of the new astronomical system was made, however, a short time before the Maragha Observatory was built in 658/1259, either by Mu’ayyad al-Din al-Urdi (d. 665/1266), in his Kitab al-Hay’a, or by Nasir al-Din al-Tusi, in his Hall-i mushkilat-i mu’iniyya. The Kitab al-Hay’a describes non-Ptolemaic models for the superior planets, Mercury and the moon; in them al-Urdi, like the rest of the members of the school, succeeds in justifying planetary motions by using linkages of vectors of constant length rotating at uniform speed and obtains results which can be compared with those of Ptolemy’s models. Al-Urdi also formulated one of the two crucial mathematical theorems which were used in the new systems, “Urdi’s lemma”. The second crucial theorem is Tusi’s couple (in Kennedy’s expression). Both theorems were known to Copernicus who used them in a way which suggests influence. In fact a close study of Copernicus’s work shows that almost all the mathematical concepts he used for his heliocentric system were originally Greek and Hellenistic. However these two concepts, central for the mathematical building of Copernicus’s system, are not from the classical sources but were developed by Muslim astronomers and used by them extensively. Tusi’s Couple consists of two circles (in fact, two spheres or orbs), one twice the size of the other. The smaller circle located inside the larger one and is tangent to the latter. If both circles perform rotation in place in such a way that the small circle rotates twice the speed of the larger in opposition direction, then the point of tangency will perform a linear motion, back and forth, along the diameter of the large circle. The important aspect of the Tusi Couple, which makes it so significant in the history of astronomy, was the fact that it could produce a linear motion form a combination of uniform circular motions. Thus, for a given planet, by using a Tusi Couple with appropriate sizes and speeds for its spheres, one can not only produce the retrograde motion, but also by moving the epicycle back and forth and by-passing the effect of the equant, produce a uniform circular motion about a central point. This is the same device that was used by Copernicus to produce the same effect, this time in a heliocentric system. The other important theorem used by Copernicus, that is Urdi’s lemma, transforms the eccentric models of planetary motions to epicyclic ones.
It is difficult to accept that Copernicus constructed and used those theorems in the same way that Muslim astronomers had established and used in a long lasting tradition starting at least from the mid-thirteenth century. Rather, there are evidence which enlighten us about possible transmission and later transformation of those concepts. In 1973, Willy Hartner discovered an interesting similarity between Copernicus’s work and that of Tusi.
On the other hand, al-Tusi built a new lunar non-Ptolemaic model which, like those of al-Urdi and al-Shirazi, keeps Ptolemy’s extreme values in the geocentric distance of the moon (and, therefore, does not correct the well-known defect in his lunar model) and gives the same longitudes as Ptolemy, but it does not use the eccentre and the centre of prosneusis employed in the Almagest. It is interesting to remark that he stated that the centre of the epicycle of the moon describes a non-circular curve. He also designed analogous models for the sun, the superior planets and Venus, but not for Mercury. These models, announced in the Hall, reached a definitive form in al-Tusi’s masterwork, the Tadhkira fi ‘ilm al-haya’a. Further mathematical research along the same line was done by al-Tusi’s disciple Qutub al-Din al-Shirazi (1236-1311) who added new models for the moon and Mercury, the latter considered by Kennedy as “the apex of the techniques developed by the Maragha School”.
Today, it seems clear that Copernicus knew, somehow, about the achievements of Maragha School; he probably became acquainted with it during his stay in Padua between 1501 and 1503 where he might have obtained, directly or indirectly, information from Byzantine manuscripts such as Ms. Gr. 211, a translation from unidentified Arabic source made by Gregory Chioniades which contains al-Tusi’s linear model as well as the famous Tusi Couple. Furthermore, one of the sources of Copernicus can be traced through the transmission of Prolemy’s kinematic models in Peurbach’s work Theoricae novae planetarum and also his Epitome in Almagestum Ptolemaei completed by Regiomantanus (d. 1476). These two works were helpful for Copernicus in getting familiar with the findings of Muslim astronomers, especially al-Battani and al-Zarqali.
From the Muslim world into Europe and vice versa After referring to Copernicus, I would like to refer now to another pupil of Padua, namely William Harvey (1578-1657), and illustrate, through his work, the circle of transmission of science. Dr. Harvey’s research and lectures on the circulation of the blood in the lungs culminated in the publication of his book Exercitatio anatomica de motucordis et sanguinis in animalibus in 1628. The circulation in the lungs had been described for the first time by the Damascene physician Ibn al-Nafis (Abu’l Hazm al-Qureshi, d. 1288) in the 13th century, in his summary of Ibn Sina’s Qanun. The influence of Ibn al-Nafis’ work into Europe can be traced through the works of Michael Servetus whose book published in 1553 (Christianismi restituto) presents the lung circulation in a way that clearly shows this influence. Similar descriptions were given later by medical authors, notably Valverde and Colombo in the 16th century. Harvey’s book which completes the blood circulation came about eighty years later.
Meantime the fame of the University of Padua had transcended its own cultural realm and especially its school of medicine became well known in the Ottoman world as well. Several Ottoman medical doctors studied at the University of Padua; among them were Muslims and Christians, Turks, Greeks and Armenians. Nuh Efendi, who was the Chief Physician of the Sultans for 12 years from 1695, studied here. From among the Ottoman Greek physicians, Panagiotis Nicoussias (d. 1673), who was the physician of Grand Vizier Köprülü Mehmed Pasha from the mid-1550s, and the illustrious Alexander Mavrocordato (d. 1709) were graduates of Padua. From among the Armenian physicians, Manuel Sashian graduated from Padua in 1801 and served two successive sultans. Sashian Pavlaki from the same family graduated form the Padua school of medicine in 1830 and became the court physician in Istanbul. Other Ottoman Armenian graduates of the school include Nishan Ayvazyan (graduated in 1870) and Andon Mimidyan (graduated in 1905).
The physician whose work I want to underline here is Alexander Mavrocordato, who wrote an innovative treatise titled Pneumaticum intrumentum circulandi sanguinis on the function of the lungs in blood circulation. The book was published in Bologna in 1664, that is about fifty years after Harvey’s book. It is considered as a most important anatomical study on lung circulation after Harvey’s book, which Mavrocordato refers to and discusses. This circle is a representative case of the transfer and development process through the successive scientific zones – from the Muslim world to Europe and then to the Muslim world until our time.
Having just mentioned some scientists whose learning or contributions passed through this University, and especially in the present time where encounters between Europe and Islam acquire increased significance in the light of factors I pointed at the beginning of my talk, it is of course not possible to proceed without referring to Ibn Rushd.
Besides his contributions in various sciences, no doubt it is in him that Islamic philosophy found the most paradigmatic applications of “reason” and “rational thinking”. He represents one of the most deeply influential efforts to understand and transmit Aristotle’s philosophy to Europe, and also one that was received most controversially in both the Muslim world and in Europe. Averroes’ impact in the Muslim world is perhaps even superseded by his seminal effect on the development of rationalism within the European context. In making Aristotle available to Aquinas and later right into the Age of Reason, it formed the line of thought that broke with Greek philosophy by introducing the concepts of the autonomy of reason and the universality of truth which form the basis of his distinction between philosophical and religious inquiry. Until this formulation of it, there had been no question in Europe about the possibility of there being two such approaches in philosophical thought. It is only after then that an exploration of “reason”, as a way of inquiry in itself, was considered. Well into the 16th century his commentaries were used as textbooks in European universities. But it is the University of Padua which became the core of Aristotelian philosophy. Bologna, Pavia, Ferrera, Venice, flourished in their own merit along these lines. The Paduan scholars upheld this philosophy. In the line that descends vertically from Ibn Rushd and the Aristotelian centers in Europe, the next landmark destination is not else than Thomas Aquinas. He lived at a critical juncture of western culture when the arrival of the Aristotelian corpus in Latin translation reopened the question of the relation between faith and reason. Aquinas, the other great interpreter of Aristotle in the medieval period, faced difficulties, as did Averroes in Islam, reconciling Aristotelian philosophy with his own religion. The influence of Averroes on Aquinas’s own rationalism is known. However, as known, Averroes was also the chief opponent whom he had to combat in order to defend and make known in quite “the true Aristotle”.
By their respective status and roles in the history of philosophy, Averroes and Aquinas personify the issue of the relationship between theology on one hand and philosophy on the other, that is to say faith and reason, each one in its own time. This by the end of the Middle Age also encompassed, by extension, the equally historic debate of the relation between religion and science - since there was no denomination of science separately from philosophy. Autonomous reason in the search of reality was reflected in the works of subsequent European philosophers. The concept of the universality of reason has been a pillar of the universality of scientific progress. Certainly, an analysis of the concepts and values that have been conducive to scientific development in specific time and geographical contexts and those that were obstructive, is a field of study in its own merit. It is relevant for not only the history of science but the inquiry on degrees of receptivity and generosity in the exchanges among cultures, seen both over time and in cross-sections. In the present world where communities’ perception of each other are increasingly affected by considerations of faith and cultural differences, if we want to build a constructive understanding between Christianity and Islam, we have to think of Copernicus, Ibn Rushd and Aquinas. Borrowings, transfers, accommodation in specific contexts, and a resulting joint contribution to universal knowledge and cultural heritage. Just as we feel grateful to our predecessors for the knowledge we owe to them, we as scholars we also feel responsible in conveying this knowledge to our successors. I believe this is a responsibility not only towards colleagues and students, but also towards public opinion, to contribute in building a better informed, more conscious, objective public opinion and protect it form falling into the whirlpool of cultural bias. I feel that increased consciousness acquired through academic life assigns greater moral duty to those in public office. All this acquires deeper significance here on these premises, and now especially for me on the present occasion. - Press Release by the Organization of the Islamic conference 11/12/06
Books from Alibris: Arabic Medicine
Books from Alibris: Arabic Medicine