To understand this anti-rationalist movement, we once again turn our gaze back to the time of the Abbasid caliph al-Mamun. Al-Mamun picked up the pro-science torch lit by the second caliph, al-Mansur, and ran with it. He responded to a crisis of legitimacy by attempting to undermine traditionalist religious scholars while actively sponsoring a doctrine called Mu’tazilism that was deeply influenced by Greek rationalism, particularly Aristotelianism. To this end, he imposed an inquisition, under which those who refused to profess their allegiance to Mu’tazilism were punished by flogging, imprisonment, or beheading. But the caliphs who followed al-Mamun upheld the doctrine with less fervor, and within a few decades, adherence to it became a punishable offense. The backlash against Mu’tazilism was tremendously successful: by 885, a half century after al-Mamun’s death, it even became a crime to copy books of philosophy. The beginning of the de-Hellenization of Arabic high culture was underway. By the twelfth or thirteenth century, the influence of Mu’tazilism was nearly completely marginalized.
In its place arose the anti-rationalist Ash’ari school whose increasing dominance is linked to the decline of Arabic science. With the rise of the Ash’arites, the ethos in the Islamic world was increasingly opposed to original scholarship and any scientific inquiry that did not directly aid in religious regulation of private and public life. While the Mu’tazilites had contended that the Koran was created and so God’s purpose for man must be interpreted through reason, the Ash’arites believed the Koran to be coeval with God — and therefore unchallengeable. At the heart of Ash’ari metaphysics is the idea of occasionalism, a doctrine that denies natural causality. Put simply, it suggests natural necessity cannot exist because God’s will is completely free. Ash’arites believed that God is the only cause, so that the world is a series of discrete physical events each willed by God.
As Maimonides described it in The Guide for the Perplexed, this view sees natural things that appear to be permanent as merely following habit. Heat follows fire and hunger follows lack of food as a matter of habit, not necessity, “just as the king generally rides on horseback through the streets of the city, and is never found departing from this habit; but reason does not find it impossible that he should walk on foot through the place.” According to the occasionalist view, tomorrow coldness might follow fire, and satiety might follow lack of food. God wills every single atomic event and God’s will is not bound up with reason. This amounts to a denial of the coherence and comprehensibility of the natural world. In his controversial 2006 University of Regensburg address, Pope Benedict XVI described this idea by quoting the philosopher Ibn Hazm (died 1064) as saying, “Were it God’s will, we would even have to practice idolatry.” It is not difficult to see how this doctrine could lead to dogma and eventually to the end of free inquiry in science and philosophy.
The greatest and most influential voice of the Ash’arites was the medieval theologian Abu Hamid al-Ghazali (also known as Algazel; died 1111). In his book The Incoherence of the Philosophers, al-Ghazali vigorously attacked philosophy and philosophers — both the Greek philosophers themselves and their followers in the Muslim world (such as al-Farabi and Avicenna). Al-Ghazali was worried that when people become favorably influenced by philosophical arguments, they will also come to trust the philosophers on matters of religion, thus making Muslims less pious. Reason, because it teaches us to discover, question, and innovate, was the enemy; al-Ghazali argued that in assuming necessity in nature, philosophy was incompatible with Islamic teaching, which recognizes that nature is entirely subject to God’s will: “Nothing in nature,” he wrote, “can act spontaneously and apart from God.” While al-Ghazali did defend logic, he did so only to the extent that it could be used to ask theological questions and wielded as a tool to undermine philosophy. Sunnis embraced al-Ghazali as the winner of the debate with the Hellenistic rationalists, and opposition to philosophy gradually ossified, even to the extent that independent inquiry became a tainted enterprise, sometimes to the point of criminality. It is an exaggeration to say, as Steven Weinberg claimed in the Times of London, that after al-Ghazali “there was no more science worth mentioning in Islamic countries”; in some places, especially Central Asia, Arabic work in science continued for some time, and philosophy was still studied somewhat under Shi’ite rule. (In the Sunni world, philosophy turned into mysticism.) But the fact is, Arab contributions to science became increasingly sporadic as the anti-rationalism sank in.
The Ash’ari view has endured to this day. Its most extreme form can be seen in some sects of Islamists. For example, Mohammed Yusuf, the late leader of a group called the Nigerian Taliban, explained why “Western education is a sin” by explaining its view on rain: “We believe it is a creation of God rather than an evaporation caused by the sun that condenses and becomes rain.” The Ash’ari view is also evident when Islamic leaders attribute natural disasters to God’s vengeance, as they did when they said that the 2010 eruption of Iceland’s Eyjafjallajökull volcano was the result of God’s anger at immodestly dressed women in Europe. Such inferences sound crazy to Western ears, but given their frequency in the Muslim world, they must sound at least a little less crazy to Muslims. As Robert R. Reilly argues in The Closing of the Muslim Mind (2010), “the fatal disconnect between the creator and the mind of his creature is the source of Sunni Islam’s most profound woes.”This is an example of how theology has affected science in Islamic societies, but theology/philosophy has just as profound an affect on all areas of life for Christians. The apostle Paul was keenly aware of this and is the reason why he structured his epistles (letters) to the different churches in the New Testament in the form of Theology followed by Application. The theology he discusses in the first portion of this letters goes hand in hand with the specific instructions that he gives for living godly lives in the second portion of this letters. Even Paul's Epistle to the Romans, follows this model, though many might assume that the book is simply a presentation of higher theology. The theology section is very large but it is to support his call for unity between Gentile and Jewish Christians.
