As I mentioned before, the writings of Aristotle were lost to the west following the close of the Peripatetic school" (school of walking philosophers) that carried on his work after his death. While Boethius had translated a few of his logical texts, most of his works did not appear until much later. Even then they were in the hands of Islamic and Nestorian Christian Philosophers. To make matters worse some of the works attributed to Aristotle at the time were written by others and were more neoplatonist. Thus, the problem of the Moslem philosophers was to make this somewhat distorted view of Aristotelianism compatible with the Koran.

When the arabs came into contact with Greek science and philosophy in the ninth century there emerged a new breed of Muslim dedicated to an ideal they called the Falsafah. The aim of the Fayllasufs (philosophers) was to live rationally in accordance with the laws that governed the universe. Since they believed the God of the Greek philosophers to be identical with Allah, they turned first to Greek science and then to Greek philosophy. According to Karen Armstrong they came to the conclusion that rationalism represented the most advanced form of religion, and that it had evolved a higher notion of God than what was revealed in the scriptures. They had no intention of abolishing religion, they wanted to purify it. It took a great courage, Armstrong said, to believe that the cosmos, where pain seemed more in evidence than a purposeful order, was really ruled by the principle of reason. They believed it was their duty to translate the Koran into the more advanced idiom developed through the ages by the best and noblest minds in all cultures. God was not a mystery, he was reason itself This is not to suggest even for a moment that the concept of a fully rational universe that dominated Greek thought was compatible with the thought of the Muslims. The Faylasufs simply considered that natural law was a manifestation of Allah. F. E Peters explained the Faylasuf's position in these terms

What falsafah added to the accumulating pieces of the Greek sciences was an epistemological claim. It brought before the Muslim an alternative theory of wisdom that simultaneously exalted itself and set down in an inferior position the channel of revelation opened by the Prophet of Islam.

This turn towards Greek philosophy, however, did not mean that the Muslims had adopted the Greek and western idea of a rational universe. Nor were the Faylasuf's attempting to develop a natural theology. The universe was created by Allah out of nothing. Thus Allah is beyond rationality. They were not searching for a reasoned explanation of the world. They were searching for a reasoned explanation of the truth of the Koran. This explains somewhat the short career of the Falsafah in the Muslim world.

The first of the Faylasuf's, Abu Yusuf Ya'qub ibn Ishaq, called Al-Kindi, maintained that human reason can work out a valid philosophical theology. He was a prolific writer who produced books on science, mathematics and religion, as well as philosophy. His works refer back both to the Profit and to Aristotle and Plato. However, the thought of his day did not see the philosophy of Aristotle and Plato as different. His Aristotle, as was most in his day, was developed at least partially from translations of Neo-platonist works. Thus it is not particularly surprising that he introduced an interpretation of Aristotle's concept of the intellect that was as much Platonic as it was Aristotelian. He regarded the active intellect as a single intelligence which comes from the outside to perform its function in individual human minds. You may recall from our discussion of Aristotle that his idea of the intellect was that it was the power whereby we recognize such things as first principles, or valid syllogisms. He departed from Aristotle too on the creation of the world. Aristotle's first mover was the ultimate cause of the world. The Koran stated that God created the world out of nothing. Some claimed that for these reasons Al-Kindi was not a true Faylasuf.

If so, then the first Faylasuf would be the Turk Faylasuf Abu Nasr Al-Farabi, in the tenth century. He argued that philosophers become aware of the truth through logical demonstrations and their own insight. Non-philosophers know truth and reality by symbols. Thus, philosophy is the highest form of knowledge. Since revealed truth is manifest through symbols, he concluded that one religion could not be suitable for all people and in any case is subordinate to philosophy. He linked the neoplatonist concept of the one with Aristotle's first cause as a self-thinking intellect or mind as well as with Allah. He claimed, in his commentaries on Plato's Republic, that the ideal ruler would be both a philosopher and a prophet. But he maintained that since no such Caliph was likely the philosopher and the politician should work closely together.

There is something outrageous in a culture that is not committed to the idea of a rational universe turning to Aristotle for an answer to the problem of truth. But the Faylasufs were a temporary phenomena of the ninth and tenth centuries. they began their deliberations with the idea that the world was a rational creation of Allah, and that did not require a rational God. If what he created was rational then reasoning was an avenue to its understanding.

Abu-Ibn-Sina, better known as Avicenna, introduced a concept that had important repercussions on later philosophy, the concept of possible being as a mode of being. He began with by showing that there was a clear distinction between essence and existence. For example, we are perfectly at ease discussing dinosaurs which do not exist because we both understand what a dinosaur is and that its nonexistence is irrelevant to our discussion. We also understand what is meant by the statement "the essence of a man can exist even though there were no men anywhere in the universe." Also, we can agree, in a very Aristotelian way, that the essence of a particular man is what it means to be that man. Thus, before he came into existence, his essence would be possible. When he was born, it would become conjoined with his existence. So, if we examine things this way, his essence and his existence can be considered two separate entities. If this were not true, and we were still thinking in these kinds of Aristotelian terms, then he could never cease to exist. He could never die. This means that possible being is a mode of being. It simply needs a cause in order to exist. This cause may be another human being, or it may be a super-natural being. Thus a being may be hypothetically necessary meaning that it must exist if some other being exists. In other words, the essence of a particular man might exist yet the man does not, however, if the man exists then his essence necessarily exists. On the other hand, a being may be absolutely necessary if it must exist in virtue of its essence. In other words, if part of the essence of a being is to exist then it cannot not exist. The point that Avicenna was trying to make was that if possible beings exist then it is necessary that an absolute being exist and that being is God.

The idea of possible being is not really consistent with Aristotle because for him the essence of something would include its cause. Therefore there could not be an essence without a cause. Every essence had to be of something that had been caused. Therefore every essence had to be of something that is. But, the introduction of possible being opened the door for some very important advancements in the idea of being, Notably by Thomas Aquinas and Leibniz.

The absolutely necessary God is the ultimate cause of all other beings. In Moslem thought he is also a personal being who knows all that proceeds from him. Creation by God, Avicenna said, is necessary not because God is coerced into creating but because of what he is, "Whatever proceeds from a necessary being must necessarily exist." He therefore made the relationship between creator and created a logical implication. From God proceeded a whole hierarchy of created intelligences each of which is necessary only through the activity of God. The tenth intelligence is the giver of the forms. Through its activity forms are received in matter, the potential becomes the actual. These things, however, come into being and pass away. This series cannot be different than it is because that would imply that God could not know things by knowing his own essence as the source of all that exists.

The tenth intelligence also has the function of illuminating the human mind. This, of course is reminiscent of Augustine and is taken from the Neoplatonic concept of spirit and world spirit. However, he explained it in Aristotelian terms. Aristotle's remarks on the ontological status of the active intellect, however, are obscure and open to various interpretations. Avicenna claimed the active intellect to be a separate intelligence. This doctrine, he felt, is derived through reason but does not contradict the Koran. He also claimed that Aristotle did not deny personal immortality because the pronoun I pertained to the soul and not the body. The soul could therefore be immortal though the body is not.

A twelfth century Moslem named Ibn-Rushd, known to Christians as Averroes developed a more strictly Aristotelian approach to philosophy. Again, he was influenced by writings attributed to Aristotle that were in fact written by others. Of particular importance is his method of freeing philosophy from its traditional conflicts with revelation. He said there are different ways of understanding the Koran that reflected different kinds of minds. The mass of mankind, hardly capable of conceiving a reality transcending the level of the sensible, can be moved by persuasive arguments and apprehend the truth only when presented in imaginative or pictorial form. The Koran caters to such minds. The next level of minds includes those who can grasp dialectical arguments. They too can grasp truths through the Koran along with Moslem theology. The highest minds are those which seek strict logical demonstrations and are capable of apprehending rational truth. For them the Koran provides material for philosophical penetration. He added an idea that was to have serious repercussions later. That was, that if there is a discrepancy between truths determined by philosophy and revelation then both were true.

This attitude made it possible for Averroes to present a description of the Aristotelian intellect that at least begins as a reasonable explanation of the words of the great philosopher himself. Averroes said that in De Anima book III Aristotle used the word intellect four different ways. The first, was what he called the imaginative power or passive intellect. Second, was the active intellect which abstracts the intelligible forms from images in the imaginative power. Third, is the material intellect, a potential principle which receives intelligible forms from the active intellect. Fourth was all of these concepts as conceived in a single entity. He went on to say that the material intellects could not be distinguished apart from the others since it was pure form. The active element, then would be the unity of all of the intellects and this must be eternal because the human race is eternal. The problem this made for western religious philosophers, Moslem, Jewish, or Christian, was that it did not provide for personal immortality.

Science and western philosophy both begin with the same assumption, that the universe is a rational place. But Greek philosophy has always aimed at the unchanging, the pure forms of the divine. Even Aristotle in his role as a biologist was searching for what is universal and consistent in individual entities. Thus Plato's contribution to geometry dealt with pure forms of geometric figures and not those found in nature. Consider the two greatest mathematicians of the period, Eudoxus and Euclid. Though friends of Plato and former students at the Academy, they made their greatest contributions outside the Academy. Aristotle would call what most scientists do in their study of the phenomena of the changing world art (techne), or production. He would consider it something different from philosophy. Later Archimedes and Ptolemy would stop short of explaining the cause of the phenomena that they found in the practical use of mathematics in such fields as mechanics or astronomy. In this totally rational world that grew out of natural forces everything came to be for a reason, a final cause or purpose. These were the purview of the philosopher. The manifestations themselves and explanations concerning them as they were found, that was the purview of the scientist. In the west they have always been separate fields. Not so in Islam. The world was created by Allah. That meant that the study of anything within it was a study of the actions of Allah. During the early middle ages science in the west could not flourish. Scientific activity in Islam developed under the Faylasuf's in their search for an understanding of Allah's world. The scientific works that had the greatest impact on Western thought were those that dealt with mathematics and astronomy. While astronomical developments throughout most of the ninth century centered around developing astrological forcasts, some important Muslim astronomers concentrated instead on developing detailed mathematically exact star charts. Abu'l Wafa' al-Buzjsni, an Iranian, wrote a complete textbook on mathematical astronomy. Another Iranian, al-Quhi, observed the summer and winter solstices and the movements of the planets and was considered to have developed the greatest mathematical accuracy obtained during the tenth century. With this added accuracy the Ptolemaic description of the planetary revolutions began to be suspect. He had developed his description around the assumption that originated in Plato's Timaeus and was backed up by Aristotle, that the stars and planets, being divine, traveled of necessity in perfect circles. The apparent wandering movements were explained by Ptolemy through the use of Homocentric spheres, an idea developed originally by Eudoxus. But even with this added assumption the results of precise measurements did not confirm the assumptions. No Muslim philosopher questioned this idea, however, it was not to be questioned until the sixteenth century and even then it was by European and not Muslim astronomers. But, to a very great extent these European developments when they did occur did so based on these accurate Muslim observations. Undoubtedly the most lasting contribution to western thought of the Muslims was the introduction of the Arabic (which they adapted from India) numeral system that we use today.

During the medieval period Jewish philosophers generally had more freedom in Moslem countries than in Christian. The most famous was Moses Ben Maimon, better known as Moses Maimonides. Born in Cordoba, he was driven from his home town by the emergence of a powerful anti-Jewish Moslem sect. He moved to Africa and finally settled in Egypt. He indicated considerable admiration for the Moslem philosopher Al Farabi and like him made Philosophical inquiry a higher standard for judging religious truths than pictorial or mythical thought. However, unlike Al Farabi, he made prophetic illumination superior to philosophical reasoning. His intent seems to be to produce a set of philosophical commentaries which would explain doctrinal concepts in philosophical terms. However, they were presented in a way that would be inexplicable to the average person.

The ideas of Maimonedes that had their greatest influence on western thought were those that dealt with God and his existence. The problem is one that occurs in all western religions. That is, how can we understand the infinity of God given the comments on him in scripture. For example, the statement, "let us make man in our own image and likeness" from Genesis is not meant to mean that God is corporeal. Maimonedes explained that God is simple. When we predicate to God a variety of attributes we are referring not to God, but to the multiplicity of Gods effects. When we make positive statements about God, such as that he is wise, we do not know what they mean to God except that they deny something of him. In this case it is that there is no wisdom that he does not possess. If we say that he is powerful what we are really saying is that he is not powerless. But most important when we said that he did not exist we would be saying that the world is self-sufficient, that there is no divine reality. That would be a statement that is false. We therefore must say that God exists but, though that statement is true, God's existence is not the same as the notion of existence as it is applied to us. We know of God by what he is not rather than what he is. When we are thinking of god we are thinking of a divine reality of which we can have no direct knowledge. It is beyond human comprehension.

An interesting highlight concerning his attempt to prove the existence of God begins with a statement concerning the perennial philosophical problem of time. While he believed that time had a beginning, philosophy had never been able to show that the world did not exist from eternity. For him this meant that a philosophical proof of the existence of God must begin with the assumption that the world did exist from eternity. In this way the more difficult case would have been proven and if it should be shown through scripture that the world had a beginning, then the argument would prove to be even stronger. He made use of Aristotle's argument for a first or supreme mover by presenting the argument several ways. He followed this by turning to Avicenna's argument that the existence of possible things (that is the essences of things that are possible even if they have never actually existed) implies the existence of a being which cannot not exist. His conclusion is that a being which is a necessarily existing being, which cannot not exist, is impled by the existence of possible beings. On the other hand, if the world had a beginning then it must have been created by God. For what has been created, existence is an accident. For God existence is part of his essence.

Resource: Provost, W. (1998). God, Science, and Reason.