George Saliba is a professor of Arabic and Islamic Science at Columbia University in New York, USA. He is an expert on the history of science, especially astronomy and mathematical sciences. On his website (http://www.columbia.edu/~gas1/saliba.html) he describes his research thusly: “I study the development of scientific ideas from late antiquity till early modern times, with a special focus on the various planetary theories that were developed within the Islamic civilization and the impact of such theories on early European astronomy.” In his recent book titled Islamic Science and Making of the European Renaissance he challenges a number of generally held views which he calls the “classical narrative” about the history and development of science in medieval times, particularly the role of scientific activities in the Islamic world and its relationship with ancient Greek science and modern European science. Carefully examining original sources, he presents evidence that challenges many of the accepted views and assumptions of the classical narrative. He also proposes an alternative thesis, again based on historical evidence. This thought-provoking book is highly recommended for anyone interested in the history, philosophy and development of science. It should also be in the reading list of those who are interested in the relationship between religion and science and the conditions in a society that lead to the rise or decline of science. This article gives a summary and description of this book.

There are seven chapters in the book. The first chapter summarizes the basic tenets of the classical narrative, then criticizes it listing many questions which the classical narrative cannot satisfactorily answer. Islamic civilization’s contribution to the development of modern science is so immense that it is impossible to completely ignore this part of the history in any serious discussion of the general history of science or civilization. The problem arises in assessing the importance and the nature of Islamic science. Generally accepted views of the classical narrative go something along these lines: Islamic civilization was a desert civilization and began to develop scientific thought only when it came in contact with more advanced civilizations (Persian, Indian and Greek and most importantly Greek). A vital component of the rise of science in Islamic civilization was the remarkable translation movement that took place during the early period of Abbasid times (750–900 CE), in which many important scientific books of other civilizations, particularly those of ancient Greeks, were translated into Arabic. The classical narrative says by learning Greek science through this translation activity, Islamic science reached its golden age while Greek science was neglected under Byzantine rule. Adherents of the classical narrative generally assume that Islamic civilization did not go much beyond translation, did not make original contributions to scientific knowledge or produced any new science of its own. They also assume this period of the golden age did not last long and came to an end with Ghazali’s “attack” on philosophers in his major work Tahafut al-Falasifa (The Incoherence of Philosophers). They assume that Islamic science began to decline with Ghazali while there was an awaking in Europe, sometimes called the Renaissance of the twelfth century, when Europeans began to translate major Arabic philosophical and scientific texts into Latin. Some of these texts had already been translated from much earlier Greek and Sanskrit texts into Arabic. So, they reconnected with their Greco-Roman legacy. The classical narrative says from that point on Europe had no need for Islamic science, hence the role of Islamic civilization was to simply translate and preserve the ancient Greek science and make it available to Europeans later. Thus, according to this view all the roots of modern science were European. The classical theory also attempts to explain the process by which the acquisition of Greek science by the Muslim world occurred. There are a few versions of this proposal which are called “contact theory,” “pocket transmission theory,” and “translation through Syriac medium first.”

In this first chapter of the book, Saliba argues that the classical narrative is an oversimplification of what actually happened in reality and fails to answer many fundamental questions. The first problem is about origins. He argues none of the proposed methods of translation is convincing to explain the reasons why, how, and when Muslims acquired Greek science. In terms of the nature and quality of translations, Saliba gives examples of sophistication and maturity exhibited by the Muslim scientists that is well beyond what would be expected from an early generation of translators who are struggling to understand a foreign science. Moreover, already in the early period of the translation movement Muslim scientists produced original new science such as algebra by al-Khwarizmi (830 CE), remarkable advances by Habash a-Hasib (850 CE) in the field of trigonometry and mathematical projections that go far beyond what was known from Indian and Greek sources, and developed decimal fractions. He argues such advances could not happen suddenly. There must be a longer tradition of scientific activity in the Islamic world and real motivations for the rise of science which cannot be explained by the classical narrative.

Not only does the classical narrative fail to explain beginnings but also more recent developments as well. Saliba gives many examples from various scientific disciplines to show that the Islamic science did not decline after Ghazali. Astronomy is a perfect counterexample to this thesis of the classical narrative, and it is not the only one. In fact, there were so many advances in astronomy in the Islamic world after Ghazali that Saliba calls the post-Ghazali period as the golden age of Islamic astronomy. Recent research in the second half of the twentieth century shows that astronomy has particularly interesting connections to the European Renaissance. Saliba comments that post-Ghazali works by the Muslim scientists were not sufficiently considered by the adherents of the classical narrative because of their pre-supposition that no significant science of any interest could have been produced in this period. This caused unfortunate damage in terms of understanding the post-Ghazali period in the Islamic world as well as the European Renaissance itself.

In the second chapter, Saliba proposes an alternative thesis/narrative to the classical narrative in terms of the beginnings of the rise of scientific activities in the Islamic world. His thesis is based on the writings of Al-Nadim (full name Abu al-Faraj Muhammad b. Abi Ya’qub Ishaq al-Nadim) who wrote about intellectual history of the early Islamic period. Saliba also supports his thesis with well known historical facts. In summary, the alternative narrative proposes that there was already a significant amount of interest and activity in the nascent Islamic civilization before the translation movement began. Rather than learning science from others (Greeks) just because they came into contact with them, the Islamic world actively sought those sciences because of a keen interest to advance their own scientific knowledge. Unlike the classical narrative, the alternative thesis argues that Muslim scientists already had a high level of knowledge and maturity when the translation activities began. This is evidenced by the high quality of translations of highly technical materials, and corrections of errors in the original sources. The main societal factors for the rise of science in the new civilization are listed as a) the need for people (bureaucrats) with a high level of scientific knowledge in administrations, and b) competition between those people to acquire higher levels of scientific knowledge to be able to advance in the ranks of governments.

In the next chapter, Saliba gives detailed examples, mostly from astronomy, to show how critically Muslim scientists received and reacted to the Greek science. They noticed observational errors and internal inconsistencies in Greek texts. They also pointed out more philosophical and foundational errors and contradictions. Muslim scientists showed a high level of sophistication, maturity and critical spirit. They had a comprehensive look at the Greek texts they translated and studied them in relation to one another. Saliba argues that it is not possible to explain these phenomena with the classical narrative. Moreover, Muslim scholars went beyond just criticizing these errors and made many novel contributions to exact sciences. In the process, they realized the proper place of mathematics in the natural sciences. Saliba also comments that Muslim scientists continued to make original contributions to astronomy and other mathematical sciences long after Ghazali, when the classical narrative would preach the death of Islamic science.

In chapter four, Saliba gives examples of critical innovations by Muslim astronomers. He remarks that the interest of the Islamic society in astronomy was very strong due to many religious requirements that need to be answered by astronomy, such as visibility of the moon, daily prayer times, and qibla (direction of worship) etc. Such problems were not considered by Greeks before. Muslim astronomers could not ignore absurdities in Ptolemaic astronomy where mathematical models in Almagest violated the fundamental cosmological assumptions in Planetary Hypotheses. Although Ptolemy’s mathematical models usually made good predictions computationally, it was not satisfactory for the scientists in the new civilization to allow those models to violate the physical properties of the celestial bodies. They took it upon themselves to propose alternative mathematical models that satisfied both requirements. They were highly successful in that quest. The solution of this problem required some new mathematical theorems. Two of the most important of such theorems were Urdi’s Lemma and Tusi couple invented by Urdi and Nasir al-Din al-Tusi in the thirteenth century. Both of these were fecund and fundamental theorems that were used repeatedly by many astronomers who followed them for a long time. Renaissance astronomer Copernicus was among those who made use of these theorems. Also noted in this chapter is Shams al-Din al-Khafri’s understanding of the role of mathematics in describing the physical phenomena.

The title of chapter five is “Science between Philosophy and Religion: the Case of Astronomy,” wherein Saliba considers the relationship between the religion of Islam and scientific developments in astronomy. He explains that religious motivations led to the creation of new disciplines such as ilm al-hay’a (science of configuration) and advances in trigonometry. He states that astronomy and trigonometry are the best examples which demonstrate the intersecting interest between the practice of a religion and scientific thinking that need to be developed as a result of that practice. Many important scientists in medieval Islam were at the same time religious authorities. A few examples among such scholars are Ibn al-Nafis, Nasir al-Din al-Tusi, Qutb al-Din al-Shirazi and Ibn al-Shatir. Saliba also notes that the European paradigm of conflict between science and religion does not exist in the Islamic world.

“Islamic Science and Renaissance Europe: The Copernican Connections” is the title of chapter six. Researchers in the second half of twentieth century first realized that many of the astronomical models of Copernicus were identical to that of Ibn al-Shatir from three centuries earlier. This surprising discovery, which contradicted the view that Renaissance science was a European self-contained creation, opened the door for further investigations which revealed more surprising outcomes. The mathematical theorem called the Tusi couple that is mentioned above plays an important role in Copernicus’s model. Copernicus stated the theorem and proved it in 1543 without mentioning that he invented a new theorem or saw it in any other source. The theorem was first invented and proved by Tusi in the middle of the thirteenth century. By comparing the two proofs, W. Hartner noticed in 1973 that Copernicus’s proof was identical to Tusi’s. He even used the same letters for essential geometric points. That is where Tusi used the Arabic letters “alif,” “ba” etc. Copernicus used the corresponding Latin letters “A,” “B” etc. This discovery makes it pretty certain that Copernicus knew about Tusi’s work.

Saliba shows Copernicus’s case is not an isolated instance and gives more evidence in this chapter of the phenomenon that “there are much too many coincidences of ideas appearing first in Arabic texts usually written between the 12th and 15th centuries, which reappear, without much explanation, in Latin sources of the 16th and 17th centuries.” Saliba’s explanation of this phenomenon is that by the Renaissance time men of science themselves learned Arabic and no longer needed translations. There are many examples that show European reliance on Arabic sciences in the post-Copernicus period when the whole worldview was supposed to have been changed by him. Renaissance men of science had a high regard for the Islamic sciences and were looking to the Islamic world for the latest in scientific activities rather than the classical Greek sources.

In the last chapter Saliba discusses the age of decline in Islamic science. He starts by rejecting the two main reasons proposed by the advocates of the classical narrative and argues that it did not start after Ghazali (eleventh century) or the destruction of Baghdad by Mongols in 1258. Saliba says that those who believe the first reason look at the Islamic civilization as a source of religious thought only and operate under the assumption that the European paradigm of conflict between religion and science applies to Islamic world as well. Saliba argues that this assumption is not true for the Islamic world and that scientific activities did not decline after Ghazali. Those who think the main reason was the destruction of Baghdad by Mongols saw the Islamic civilization mostly in political terms and paid little attention to its intellectual history. Saliba gives many examples of high quality and sophisticated scientific production in the Islamic world, mostly in astronomy but in other areas as well, well after both of these events. He says those examples were ignored or not properly read by the adherents of the classical view who did not expect to find any important scientific production in the Islamic world after the thirteenth century.

There still remains the problem and timing of decline of science in the Islamic world. When did it happen? Saliba notes that decline is a relative concept. What actually happened was the European science advanced more rapidly than the rest of the world after the sixteenth century. Hence it looked like science declined elsewhere, including the Islamic world. According to Saliba the main reason for these rapid developments in science in Europe was related to the discovery of the “new world.” He argues that the wealth and resources obtained by Europeans as a result of discovery of new lands helped them fund scientific activities. Europe witnessed the rise of royal and scientific academies where most educated men of the time were assembled and engaged in scientific research without having to worry about financial needs. Healthy competition among these institutions led to new scientific discoveries. Western superiority in science continues to this day and the constant brain drain that feeds the West at the expense of the developing and third worlds does not help to change the balance.

In summary, this book presents fundamental challenges to many of the commonly held views about the intellectual and scientific history of the Islamic world and proposes alternative explanations. The science of astronomy is used as a template to test and justify these claims. The author invites researchers to subject his proposals to the test of historical data in other disciplines as well. This book is highly recommended to all interested in the general history of science, and that of the Islamic world and the Renaissance period in particular.

Nuh Aydin is an associate professor of Mathematics at Kenyon College, Ohio, USA.