Are there any limits of God’s omnipotence—maybe imposed by God himself on himself? Of course, as an omnipotent creator, God can do whatever he wants with his creation—but does he actually do it? Or does he leave some amount of freedom for the world to proceed by itself, based on laws that he imposed on it at the moment of creation? Is such a freedom also given to humans, as a “freedom of choice”? Should people be allowed to make up their own minds about what is good and evil? Should thinking about the world or God be allowed at all—or should people just believe in whatever the holy scriptures of their religion say? These and similar questions occupied the minds of many Christians and Muslims.

In Islam, three main ideological movements were established early on. They were the “traditionalists”, who relied on Islamic traditions (in particular the hadiths, the sayings and deeds of the prophet Mohammad and for whom these traditions and belief in God were the only way to truth, the theologians (mutakallimin, the practitioners of kalam or theology) who, while also supporting religion wholeheartedly, wanted to go beyond faith and wanted to be able to reason about religious questions using Aristotelian logic, and the philosophers (falasifa) who wanted to go beyond thinking about religion and include also non-religious topics in their debates. Each of these ideological movements—and their many sub-movements—often fought each other bitterly.

This is what Ibn Hanbal, one of the most famous traditionalists (the name-giver of the “Hanbali” school of Islamic jurisprudence) believed about God:

The predetermination of everything is from Allah, both of the good and the evil, of the little and the much, of what is outward and what is inward, of what is sweet and what is bitter, of what is liked and what is disliked, of what is fine and what is bad, of what is first and what is last. … Adultery, theft, wine-drinking, homicide, consuming unlawful wealth, idolatry and all sins come about by Allah’s decree and predetermination, without any of the creatures having an argument against Allah, although He has a conclusive argument against His creatures. He is not questioned about what He does, but they are questioned. The knowledge of Allah is efficacious in respect of His creatures by a volition from Him … Everyone does what he was created to do, and comes to what was decreed for him and known about him. Not one of them opposes Allah’s predetermination and His will. Allah is the doer of what He decides on and the accomplisher of what He wills. (Watt, 1994, p. 30)

In other words: God pre-determines everything in the world, the good and the bad and humans have to accept whatever he determines, without questioning.

In contrast to the traditionalists who insisted on relying on the Quran and the other holy texts alone, both the theologians and the philosophers were influenced by the Greek philosophical works translated during the great Islamic translation movement which started in the 8th century.

An early theological school were the qadarites who rejected predestination and who insisted that humans had a free will. The theological school of the Mu’tazilites appeared in the 8th century, during the last phase of the Umayyad caliphate (661-750). Like the qadarites , they emphasized free will. Maybe influenced by pre-socratic Greek thinkers, e.g. Democritus, they thought of the world as consisting of atoms. God entered the picture in the form of a strikingly radical atomistic “occasionalism”:

Similar to the Greek Atomists, the Basra Mu’tazila held that physical reality is composed of basic physical entities or atoms … God creates the world in each instant by creating atoms and attributes … creation is thus a continual divine activity (Martin, Woodward and Atmaja, 1997, Location 477).

Thus, God recreates all atoms in the whole universe in each moment, in a slightly different constellation, giving an illusion of change. There is no causal relationship between the atoms at time point t1and those at the next time point t2.

The Mu’tazilites used rationalist methods to defend their views. They accepted some limitations on the absolute power of God, in particular by stating that God is rational and thus obeys principles of rationality. He is also just and thus cannot act unjustly (Reilly, 2010, p. 28). Furthermore, they accepted one exception to divine causation: humans were able to make free choices. Thus they were the cause of their own actions and responsible for them (Martin, Woodward and Atmaja, 1997, Location 477).

Mu’tazilite ideas became adopted by the rulers in Baghdad, and their teaching that the Quran was not eternal but was instead created by God became state doctrine in 833 under the Abbasid caliph Mamun. Traditionalist Muslims who didn’t want anything to do with the rationalist ideas of the Mu’tazilites were oppressed during a 15 year period of religious inquisition (mihna). During this persecution the traditionalist Ibn Hanbal was imprisoned and flogged.

The flourishing of the Mu’tazilites, however, didn’t last: caliph Mutawakkil stopped the persecution of traditionalists in 848 and state support for the Mu’tazilites’ views was withdrawn. Their influence vaned and the “traditionalists” who were earlier persecuted became influential again. Mu’tazilite influence was further weakened in the 10th century by al-Ashari, a former Mu’tazilite. Al-Ashari held the same sort of atomistic occasionalist views as the Mu’tazilites: the world consists of atoms and God recreates these atoms in every moment  (Reilly, 2010, p. 60). However, al-Ashari went further than the Mu’tazilites, by emphasizing God’s influence on humans actions, too:

In contrast to the emphasis of the Mu’tazila on the reality of choice in human activity, al-Ash’ari insisted on God’s omnipotence; everything, good and evil, is willed by God, and He creates the acts of men by creating in men the power to do each act (Islamic Philosophy Online)

Either al-Ashari himself or his followers, the Asharites, later tried to save some of human free will by introducing the concept of kasb (acquisition). There are many interpretations about the  meaning of this, but roughly it means that, after God creates the power to act in the person, the person then “acquires” this power and thus becomes responsible for the act which follows. Some maintain that the concept of “acquisition” allows free choice between alternatives:

God creates in man the power and ability to perform an act. He also creates in him the power (ikhtiyar) to make a free choice between two alternatives between right and wrong. (Martin, 2013, Location 405)

For others, however, the “power” created by God in the person is for a particular act:

Suppose … that I intentionally strike you and, as a result, you fall into a coma. As al-Ashʿarī sees it, this occurs by God creating in me a power through which I generate your falling into a coma. This power is a power for a specific action, namely, my striking you in a particular way at this particular time.(Stanford Encyclopedia of Philosophy; italics by Z.S.)

This seems to mean that the person has no choice: the action is specified by God in all its detail. Similarly, Naseem’s (2001) description of al-Ashari’s “acquisition” states that not only the “power” but the “choice” is created by God :

In this way we can say that according to al-Ashari man cannot create a thing; God is the only creator … [He] creates in His creatures power (qudrah) and choice (Ikhtiyar). (Naseem, 2001, p. 36)

Already these few quotations show how obscure al-Ashari’s concept of “acquisition” is and how many different interpretations it has. One problem seems to be the different translations of the terms to English. For example, in Martin (2013) above, ikhtiyar is translated as “power”, while in Naseem (2001) ikhtiyar is translated as “choice” and “power” corresponds to qudrah.

But, whether some “acquisition” process enables some choice by the person or not, there is agreement that it is God who initiates every single action in the person.

How did the Asharites think about questions of good and evil? How to determine which deeds are good and which are bad? Even thinking about such things was deemed wrong: God alone determines what is good and what is evil. And how does he do that? We don’t know, can’t know and should not ask: God alone knows. We have to simply accept as good whatever God deems as good and as bad whatever God deems to be bad:

… good and evil are only conventions of Allah’s—some things are halal (permitted/lawful) and others haram (forbidden/unlawful), simply because He says so and for no reasons in themselves. Evil is simply what is forbidden. What is forbidden today could be permitted tomorrow. (Reilly, 2010, p. 70)

Thus, what we are left with, according to the Asharites, is an omnipotent God who determines every single event directly—except maybe human actions, where some level of choice might be available for humans via an “acquisition” process (though, as shown above, it is doubtful if Asharites allow even such an exception). This God gives absolute, unquestionable instructions to mankind about how to behave. Independent thinking about anything is discouraged. The only thing that remains is the unconditional, unthinking acceptance of God’s omnipotence and the unquestioning surrender to his will.

The Mu’tazilites were soundly defeated by the traditionalists and by the Asharites. They never regained their previous influence, and Mu’tazilism is seen in the Islamic world until today as close to heresy.

The Asharites themselves were fiercely opposed by the traditionalists, too, who were against any kind of theological speculation. During the mid-11th century, they were cursed from the pulpits of Baghdad mosques (Reilly, 2010, p. 91). However, things changed when the vizier al-Mulk came to power who was sympathetic towards the Asharites. Al-Mulk stopped the curses against the Asharites in around 1063 and started supporting them.

In 1067, al-Mulk opened a college in Baghdad, the Nizamiyya, to propagate Ash‘arite teachings, and founded at least eight more in places ranging from Mosul to Herat. (Reilly, 2010, p. 91)

In addition to opposing the Mu’tazilites, the Asharites’ main  target were the falasifa, the philosophers, who, like the Mu’tazilites, were rational thinkers, strongly influenced by Greek philosophy, in particular by Aristotle. Al-Kindi, Avicenna (Ibn Sina), al-Farabi and Averroes (Ibn Rushd) were some of the most famous of these Muslim philosophers.

The Asharite scholar al-Ghazali who headed the Nizamiyya college between 1091 and 1095 (Reilly, 2010, p. 91), wrote the influential book The Incoherence of the Philosophers criticising the views of these falasifa.

His arguments against natural causation, put forward in that book, became famous. For example, he wrote:

The connection between what is habitually believed to be a cause and what is habitually believed to be an effect is not necessary, according to us. But [with] any two things … it is not a necessity of the existence of the one that the other should exist … for example, the quenching of thirst and drinking, satiety and eating, burning and contact with fire, light and the appearance of the sun, death and decapitation, healing and the drinking of medicine, the purging of the bowels and the using of a purgative, and so on … Their connection is due to the prior decree of God, who creates them side by side (Al-Ghazali, 2000, p. 166)

Thus, when a piece of cotton burns after we put a burning match next to it is not because it was lit by the burning match. It is because God, for some reason, creates these two events—the the match burning and cotton catching fire—in close spatial and temporal proximity, one after the other. There is no causal relationship between these events; they are separate without any connection to each other. The only causal factor is God’s will.

After it received state support for their views in the mid-11th century, Asharism was on its way to become mainstream in Muslim thinking:

Indeed, the ulema (Islamic legal scholars) of every [law] school but the literalist Hanbali came to accept Asharism (Reilly, 2010, p. 91).

The attacks on the falasifa continued. For example, Ibn al-Salah, a hadith-specialist who lived in the 13th century, wrote:

Those who think that they can occupy themselves with philosophy and logic … are betrayed and duped by Satan … All those who give evidence of pursuing the teachings of philosophy must be confronted with the following alternatives: either (execution) by the sword or (conversion) to Islam so that the land may be protected and the traces of those people and their sciences may be eradicated (Goldziher, 1981, p. 206, quoted in Grant, 2008, p. 514)

The 14th century Asharite theologian al-Iji rejected not only much of Aristotelian philosophy but also rejected the basic dynamics of the Ptolemaic system—of course, not because he had any scientific evidence that it was wrong. Instead, the reason for his rejection was that it described an inherent inclination of heavenly objects to move in circles (Huff, 2017, p. 167). For an Asharite like Al-Iji, natural causes, inherent in objects, were not possible: God was the only cause for everything, including the movements of planets and stars.

Both Ibn al-Salah and al-Iji were highly respected by Muslims. Al-Iji was so influential that his theological works were used up to the mid-20th century for teaching at the Al-Azhar madrasa in Cairo.

At the end, the ideological battle between rational and religious thinking in the Muslim world was decided in favor of religion. Both rationally minded theologians (the Mu’tazilites) and the falasifa, Muslim philosophers deeply influenced by Greek philosophy, disappeared from the intellectual scene. Hanbalites and other “traditionalists” on the one hand and Asharite theologians on the other were to influence Muslim thinking decisively.

How was the same tension resolved in Western Europe? There, as mentioned above, translations of Aristotle’s works were rare until the 12th century. However, a number of Plato’s dialogues had been available and very influential before that. The effect of Plato on 12th century European theologian-philosophers like William of Conches and Thierry of Chartres was an extraordinary “naturalism”. David C. Lindberg writes about these developments:  

… under Platonic inspiration [Thierry of Chartres] restricts direct divine intervention to the initial moment of creation; what happens afterward is the result of natural causation … Even the appearance of Adam and Eve … did not call for miraculous intervention … This naturalism is one of the most salient features of twelfth-century natural philosophy. (Lindberg, p. 210)

Just as in Islam during the flourishing of the Mu’tazilites and of the falasifa, there was an enthusiastic reception of Aristotle’s books, as soon as they became widespread in Latin translation:  

From modest beginnings in the twelfth century, Aristotle’s influence grew until, by the second half of the thirteenth century, his works … became compulsory objects of study. No student emerged from a university education without a thorough grounding in Aristotelian natural philosophy. (Lindberg, 2007, p. 223)

The influence of Aristotle on Western European thinking can be illustrated by the views of  the Dominican friar Albertus Magnus, one of the most respected European scholars of the 13th century.

He acknowledged … that God is ultimately the cause of everything, but he argued that God customarily works through natural causes and that the natural philosopher’s obligation was to take the latter to their limit … Albert pointed out that God employs natural causes to accomplish his purposes; and the philosopher’s task is not to investigate the causes of God’s will, but to inquire into the natural causes by which God’s will produces its effect. (Lindberg, 2007, p. 241)

However, the religious opposition didn’t wait very long in Europe, either. The story of teaching Aristotle at the University of Paris is a good illustration of the tension between religion and philosophy as it was played out in Western Europe. The University of Paris was founded in 1200 and scholars presumably started teaching Aristotle immediately afterwards. However, just ten years later, in 1210, teaching of Aristotelian natural philosophy became forbidden. In 1231, the University asked the pope to lift the total ban on teaching Aristotelian natural philosophy. The pope answered by calling for a “cleaning” of Aristotle’s works from material objectionable from the Church’s perspective, so that the rest could be safely taught. The committee which was supposed to “clean” Aristotelian teachings apparently never met but the ban on teaching Aristotle was not enforced, anyway. Teaching Aristotle soon fully resumed at the University of Paris, with Albertus Magnus and Thomas Aquinas—a Dominican friar like Albertus—as significant proponents of it.

The struggle, however, didn’t end there: in 1270 the bishop of Paris forbid the teaching of 13 Aristotelian propositions, and in 1277 he condemned 219 doctrines of Aristotle (and of Thomas Aquinas). These condemnations lasted almost 50 years, until 1325, when they were lifted (at least partially) by another bishop of Paris.

It seems that the lifting of the condemnations in 1325 affected only those few of them which were directed against Thomas Aquinas. The rest of the dozens of condemnations remained theoretically in power for years. But they didn’t seem to have much of an effect: Aristotelian teaching at the University of Paris soon recovered to such an extent that new teachers at the University of Paris in the 1340’s were required to swear that they’ll teach Aristotle (Lindberg, 2007, p. 251). Thomas Aquinas himself was fully vindicated when he was canonized by the Catholic church in 1323.

Thus, in contrast to Islam, in Western Europe philosophy triumphed against attempts by the fundamentalist religious opposition to suppress it. Rationality and thinking about the world, about human affairs and about God did not become forbidden. True, philosophy was seen as subservient to theology, as its “handmaiden”, but ultimately it was allowed to have its own place.

It is worthwhile comparing the treatment of Thomas Aquinas by the Catholic church to that experienced by the 12th century Muslim philosopher Averroes (Ibn Rushd). Averroes was a prominent commentator on Aristotle and wrote a book critiquing al-Ghazali’s Incoherence of the Philosophers.

Both Thomas Aquinas and Averroes were attacked for their Aristotelian leanings by the religious establishment. Aquinas eventually became a Christian saint a few decades after his death and his main work, Summa theologiae—in which Aquinas combined Christian religion with his Aristotelian ideas—became uniquely important for Christian theology. In contrast, Averroes, after initially being in favor of the rulers in Muslim Spain, was banished and in 1195 his books were burned in Cordoba. While Averroes’ work commenting on Aristotle became highly regarded in the Christian West (he was so well known that he was simply called the “Commentator” and had a strong influence on the thinking of Thomas Aquinas, among others), Muslim attempts at combining religion and Aristotelian philosophy ceased in Islam with the death of Averroes in 1198. His writings remained unknown in the Muslim world and he is controversial in the Muslim world even today:

Some Middle Eastern philosophers still portray Averröes as a heretic … the scholars of Al-Azhar, the oldest madrasa in Egypt that became a university in the twentieth century, banned the showing of a film on Ibn Rushd that portrayed him as a progressive Islamic thinker. (Huff, 2017, p. 93)

What was the reason for these differing developments in Islam and in Christianity? How could  religious ideas as radical as the occasionalism of al-Ashari and al-Ghazali win in Islam? Why did the Islamic religion, over time, suppress rationalistic philosophy? Why, in contrast, was there  a reconciliation between philosophy and religion in Christianity?