Factors other than the holy scriptures of the two religions probably also had an important effect on science prospering in Western Christianity and declining in Islam-dominated areas.

Separation between church and state

One fundamental difference between Christianity and Islam was (and is) that in Christianity there is a much clearer separation between the religious and secular domains of society (“separation between church and state”). This separation was mirrored by the separation between theology and philosophy at Western European universities. Philosophy was seen as a secular enterprise, subordinated to theology (the “handmaiden” of theology). Nevertheless, a separate existence was conceded to it. At the same time, however, most European philosophers of the Middle Ages were also theologians or churchmen who were often enough able to integrate philosophical views originating with Plato or Aristotle into Christian theology.

In Islam, in contrast, there is no separation between “church and state”. The existence of societal domains separate from religion is not conceivable and must be suppressed.

The Stanford Encyclopedia of Philosophy writes:

In the classical period [of Islam], at least, theology and philosophy developed separately. Indeed, philosophy’s independence from theology in this period is striking as compared to its subordinate status as the handmaid of theology in the Medieval Latin West.

“Philosophy’s independence from theology” in Islam almost sounds like a positive thing, until one remembers what this meant: no acceptance of philosophy teaching in higher education and bitter animosity by theologians (both by “traditionalists” and Asharites) towards the philosophers. Philosophy “developed” separately because it was being pushed away by mainstream Islamic theology. The latter tried to suppress philosophy, with success: philosophy in its Aristotelian form more or less disappeared in Islam after the death of Averroes in 1198.

Cultural acceptance of antique authors

In Islamic areas the Greek authors and their works were always seen as foreign and thus were always seen with a degree of suspicion:

… the consciousness of a definite distinction between indigenous and foreign sciences never disappeared, however much the Muslim scholars might have made their own and added to the classical bequest … The study of these foreign sciences, however intense and fruitful, never fought clear of a measure of distrust on the part of the pious. In fact, the animosity toward these studies increased in the later Middle Ages (von Grunebaum, 1955, p. 15).

Similarly, as Edward Grant writes in his book A History of Natural Philosophy: From the Ancient World to the Nineteenth Century:

Not only was Greek philosophy regarded as a foreign science, but the term philosopher (failasuf; plural: falasifa) was employed pejoratively (Grant, 2007, p. 69).

In Christianity, though there was some suspicion towards these “pagan” antique authors, they were seen as far less “foreign”; there was an awareness of the historical continuity between the Greco-Roman culture and the Christian one. Most European philosophers were also theologians or churchmen. This contrasted with Islam.

The more relaxed attitude to pagan philosophy in Europe permitted an easier acceptance of these antique works, also by religious scholars, who attempted to integrate Greek philosophy and Christianity. This led to a stronger foundation for the development of science. Conversely, the stronger suspicion towards these “foreign” sciences in Islam made the foundations for the development of science weaker.

Higher education

In his book Intellectual Curiosity and the Scientific Revolution, Toby Huff mentions differences between the institutions of Western and Muslim higher education. In the West, universities became corporations very early on, meaning that they had legal autonomy. They were thus able to create their own rules and regulations. As we saw in the example of the ups and downs of Aristotelian teachings at the University of Paris, there was tension between the University and religious authorities and the latter were able to override the universities’ rules, limiting their autonomy. Still, the autonomy of the University allowed it for pushing matters in its own interests, for example when it asked the pope in 1231 to lift the total ban on Aristotelian teaching. And, whenever it was not explicitly forbidden for the Universities, teaching natural philosophy, in particular of Aristotle, was always on the curriculum.

All this was very different in the Muslim world. There, the madrasa system was the main institution which came into being in the 11th century. They were religious trusts (waqf), founded by a Muslim, without any notion of corporal identity or legal autonomy. The founder had a large amount of control over the madrasa, for example over its administration and teaching staff (Grant, 2008, p. 519).

But the founder of the madrasa had to accept one condition: the terms of the foundation could not violate the tenets of Islam (Grant, 2008, p. 519).  

Who determined what did and what did not violate the tenets of Islam? It must have been members of the religious establishment, of the ulama. We have seen above the attacks by very influential members of the ulama—like Ibn al-Salah and Al-Iji—against the “foreign sciences” and thus it is no surprise to learn that the madrasas didn’t teach natural philosophy at all. Even medical science, which otherwise was recognized as important in the Muslim world, was only rarely on the curriculum (though it was taught in other settings, as in hospitals). Teaching at the madrasas was focused on religion and religious law, though grammar, history, logic, mathematics, and even astronomy—which was thought of as a mathematical science, not something necessarily to do with how the universe really worked—were also taught. Emphasis was put on rote learning of religious texts. People interested in the “foreign sciences” or in Aristotelian natural philosophy were forced to study these things privately.

These differences in the educational system reflect what has been said earlier about differences in culture and ultimately in the holy scripts: though the West was highly religious, it also allowed a place for natural laws and for their study. In contrast, after the triumph of the thinking of the Asharites and of al-Ghazali, religion acquired an overwhelming influence in Islam.

Institutional support for science

Another institutional factor was the reliance on support for science by the ruler. Such support was important both in Islam and in the West but probably more so in Islam. While in the West the universities and learned societies of scientists provided a relatively independent place of research as an alternative, the great research institutes in the Islamic world, like the Maragha observatory or the Samarkand observatory of Ulugh Beg, relied on support by a ruler. If the ruler lost interest or when he died, he or his successor might have stopped the support, threatening the institution’s existence. This is what seems to have happened to the Baghdad observatory when it ceased its activity a few years after the death of its founder, the Abbasid caliph Al-Mamun. Activity at the Maragha observatory seems to have stopped for similar reasons. In addition, the religious establishment and the religious population were sometimes able to bring to a halt grand scientific projects supported by rulers, like the nearly completed Cairo observatory in 1225,  Ulugh Beg’s observatory in 1449, and the Istanbul observatory in 1580.

Averroes’ initial support by the ruler didn’t help him, either, when he was banned and his books were burned by the ulama.

Spread of ideas

Until the 15th century, in both Christianity and in Islam books were reproduced by copying them manually—a slow and expensive process. Then, in Europe the printing of books was started by Johann Gutenberg in around 1440. Book printing—using movable metal types and paper—made the production of books much cheaper and faster. Works of Christian natural philosophers were among the first books to appear in print. Some of these books had many editions. James Hannam writes in God’s philosophers:

The fact that printers were willing to invest the capital outlay on many editions of these works shows that there was demand for them (Hannam, 2009, p. 210).

This high demand shows how hungry people were for the ideas presented in these books. Book printing was able to satisfy this hunger much more efficiently and it increased the speed—and reach—with which scientific and philosophical ideas spread in Europe.

In contrast to these developments, in the most important Islamic state, the Ottoman empire, book printing in Arabic was forbidden by the Turkish Sultan Bayezid II end of the 15th century. This prohibition was confirmed by his son, Selim I, twenty years later (Pedersen, 1984, p. 133). Printing remained forbidden until 1729 when a Hungarian renegade set up a printing press in Istanbul and printed a number of books with secular topics. Printing of religious material was not allowed. The printing press closed in 1742, and printing in Arabic was resumed only at the beginning of the 19th century.

The reason for forbidding printing in the Ottoman empire is not quite clear: some people suggest that Muslim clerics were afraid that printing religious texts, particularly the Quran, might be sacrilegious, some even maintaining that the mechanical process involved in printing—pressing—was of particular religious concern. One particular fear seems to have been that printing the Quran could have resulted in printing errors and thus potentially in different versions of the Quran. This explanation has some merit: as mentioned above, printing of religious material was forbidden during the few short years of book printing in the 18th century. If these explanations are true, they again confirm the grip of religion on Muslim society, to the detriment of societal progress.

A more mundane explanation which is sometimes invoked is that the copyists whose job was producing book copies feared losing their job if printing was allowed.

Whatever the reason, manual copying of books made them much less available, and thus resulted in a stunted communication among the intellectual elite, especially as compared to contemporary Europe.

It seems that the additional factors mentioned in this chapter are all connected to the influence of religion which received a boost through the triumph of Asharite and al-Ghazalian thinking in Islamic society.