Islamic philosophy may be defined in a number of different ways, but the perspective taken here is that it represents the style of philosophy produced within the framework of Islamic culture. This description does not suggest that it is necessarily concerned with religious issues, nor even that it is exclusively produced by Muslims.

1-The early years of Islamic philosophy
Islamic philosophy is intimately connected with Greek philosophy, although this is a relationship which can be exaggerated. Theoretical questions were raised right from the beginning of Islam, questions which could to a certain extent be answered by reference to Islamic texts such as the Qur’an, the practices of the community and the traditional sayings of the Prophet and his Companions. On this initial basis a whole range of what came to be known as the Islamic sciences came to be produced, and these consisted largely of religious law, the Arabic language and forms of theology which represented differing understandings of Islam.
The early conquests of the Muslims brought them into close contact with centres of civilization heavily influenced by Christianity and Judaism, and also by Greek culture. Many rulers wished to understand and use the Greek forms of knowledge, some practical and some theoretical, and a large translation project started which saw official support for the assimilation of Greek culture. This had a powerful impact upon all areas of Islamic philosophy. Neoplatonism definitely became the prevalent school of thought, following closely the curriculum of Greek (Peripatetic) philosophy which was initially transmitted to the Islamic world. This stressed agreement between Plato and Aristotle on a range of issues, and incorporated the work of some Neoplatonic authors. A leading group of Neoplatonic thinkers were the Ikhwan al-Safa’ (Brethren of Purity), who presented an eclectic philosophy designed to facilitate spiritual liberation through philosophical perfection. However, there was also a development of Aristotelianism in Islamic philosophy, especially by those thinkers who were impressed by the logical and metaphysical thought of Aristotle, and Platonism was inspired by the personality of Socrates and the apparently more spiritual nature of Plato as compared with Aristotle. There were even thinkers who seem to have been influenced by Greek scepticism, which they turned largely against religion, and Ibn ar-Rawandi and Muhammad ibn Zakariyya’ al-Razi presented a thoroughgoing critique of many of the leading supernatural ideas of Islam.
Al-Kindi is often called the first philosopher of the Arabs, and he followed a broadly Neoplatonic approach. One of the earliest of the philosophers in Baghdad was in fact a Christian, Yahya Ibn ‘Adi, and his pupil al-Farabi created much of the agenda for the next four centuries of work. Al-Farabi argued that the works of Aristotle raise important issues for the understanding of the nature of the universe, in particular its origination. Aristotle suggested that the world is eternal, which seems to be in contradiction with the implication in the Qur’an that God created the world out of nothing. Al-Farabi used as his principle of creation the process of emanation, the idea that reality continually flows out of the source of perfection, so that the world was not created at a particular time. He also did an enormous amount of work on Greek logic, arguing that behind natural language lies logic, so that an understanding of the latter is a deeper and more significant achievement than a grasp of the former. This also seemed to threaten the significance of language, in particular the language – Arabic – in which God transmitted the Qur’an to the Prophet Muhammad. A large school of thinkers was strongly influenced by al-Farabi, including al-‘Amiri, al-Sijistani and al-Tawhidi, and this surely played an important part in making his ideas and methodology so crucial for the following centuries of Islamic philosophy.
Ibn Sina went on to develop this form of thought in a much more creative way, and he presented a view of the universe as consisting of entirely necessitated events, with the exception of God. This led to a powerful reaction from al-Ghazali, who in his critique of Peripatetic philosophy argued that it was both incompatible with religion, and also invalid on its own principles. He managed to point to some of the major difficulties with the developments of Neoplatonism which had taken place in Islamic philosophy, and he argued that while philosophy should be rejected, logic as a conceptual tool should be retained. This view became very influential in much of the Islamic world, and philosophy came under a cloud until the nineteenth century.

2- Philosophy in Spain and North Africa
A particularly rich blend of philosophy flourished in al-Andalus (the Islamic part of the Iberian penninsula), and in North Africa. Ibn Masarra defended a form of mysticism, and this type of thinking was important for both Ibn Tufayl and Ibn Bajja, for whom the contrast between the individual in society and the individual who primarily relates to God became very much of a theme. The argument was often that a higher level of understanding of reality can be attained by those prepared to develop their religious consciousness outside of the framework of traditional religion, a view which was supported and became part of a highly sophisticated account of the links between religion and reason as created by Ibn Rushd. He set out to defend philosophy strenuously from the attacks of al-Ghazali, and also to present a more Aristotelian account than had been managed by Ibn Sina. He argued that there are a variety of routes to God, all equally valid, and that the route which the philosopher can take is one based on the independent use of reason, while the ordinary member of society has to be satisfied with the sayings and obligations of religion. Ibn Sab‘in, by contrast, argued that Aristotelian philosophy and logic were useless in trying to understand reality since those ideas fail to mirror the basic unity which is implicit in reality, a unity which stems from the unity of God, and so we require an entirely new form of thinking which is adequate to the task of representing the oneness of the world. A thinker better known perhaps for his work on history and sociology than in philosophy is Ibn Khaldun, who was nonetheless a significant philosophical writer; he presents an excellent summary of preceding philosophical movements within the Islamic world, albeit from a conservative (Ash‘arite) point of view.

3- Mystical philosophy
Mystical philosophy in Islam represents a persistent tradition of working philosophically within the Islamic world. Some philosophers managed to combine mysticism with Peripatetic thought, while others saw mysticism as in opposition to Peripateticism. Al-Ghazali had great influence in making mysticism in its Sufi form respectable, but it is really other thinkers such as al-Suhrawardi and Ibn al-‘Arabi who produced actual systematic mystical thought. They created, albeit in different ways, accounts of how to do philosophy which accord with mystical approaches to reality, and which self-consciously go in opposite directions to Peripateticism. Ibn al-‘Arabi concentrated on analysing the different levels of reality and the links which exist between them, while al-Suhrawardi is the main progenitor of Illuminationist philosophy. This tries to replace Aristotelian logic and metaphysics with an alternative based on the relationship between light as the main principle of creation and knowledge, and that which is lit up – the rest of reality. This tradition has had many followers, including al-Tusi, Mulla Sadra, Mir Damad and al-Sabzawari, and has been popular in the Persian world right up to today. Shah Wali Allah extended this school of thought to the Indian subcontinent.

4- Islamic philosophy and the Islamic sciences
Islamic philosophy has always had a rather difficult relationship with the Islamic sciences, those techniques for answering theoretical questions which are closely linked with the religion of Islam, comprising law, theology, language and the study of the religious texts themselves. Many theologians such as Ibn Hazm, al-Juwayni and Fakhr al-Din al-Razi presented accounts of Islamic theology which argued for a particular theory of how to interpret religious texts. They tended to advocate a restricted approach to interpretation, rejecting the use of analogy and also the idea that philosophy is an objective system of enquiry which can be applied to anything at all. Most theologians were Ash‘arites, which meant that they were opposed to the idea that ethical and religious ideas could be objectively true. What makes such ideas true, the Ash‘arites argued, is that God says that they are true, and there are no other grounds for accepting them than this. This had a particularly strong influence on ethics, where there was much debate between objectivists and subjectivists, with the latter arguing that an action is just if and only if God says that it is just. Many thinkers wrote about how to reconcile the social virtues, which involve being part of a community and following the rules of religion, with the intellectual virtues, which tend to involve a more solitary lifestyle. Ibn Miskawayh and Al-Tusi developed complex accounts of the apparent conflict between these different sets of virtues.
Political philosophy in Islam looked to Greek thinkers for ways of understanding the nature of the state, yet also generally linked Platonic ideas of the state to Qur’anic notions, which is not difficult given the basically hierarchical nature of both types of account. Even thinkers attracted to Illuminationist philosophy such as al-Dawani wrote on political philosophy, arguing that the structure of the state should represent the material and spiritual aspects of the citizens. Through a strict differentiation of role in the state, and through leadership by those skilled in religious and philosophical knowledge, everyone would find an acceptable place in society and scope for spiritual perfection to an appropriate degree.
Particular problems arose in the discussions concerning the nature of the soul. According to the version of Aristotle which was generally used by the Islamic philosophers, the soul is an integral part of the person as its form, and once the individual dies the soul disappears also. This appears to contravene the notion of an afterlife which is so important a part of Islam. Even Platonic views of the soul seem to insist on its spirituality, as compared with the very physical accounts of the Islamic afterlife. Many of the philosophers tried to get around this by arguing that the religious language discussing the soul is only allegorical, and is intended to impress upon the community at large that there is a wider context within which their lives take place, which extends further than those lives themselves. They could argue in this way because of theories which presented a sophisticated view of different types of meaning that a statement may have in order to appeal to different audiences and carry out a number of different functions. Only the philosopher really has the ability to understand this range of meanings, and those who work in the Islamic sciences do not know how to deal with these issues which come outside of their area of expertise. While those skilled in dealing with the law will know how to adjudicate between different legal judgements, we need an understanding of the philosophy of law in Islam if we are to have access to what might be called the deep structure of law itself. Similarly, although the Qur’an encourages its followers to discover facts about the world, it is through the philosophy of science that we can understand the theoretical principles which lie behind that physical reality.
Many of the problems of religion versus philosophy arose in the area of aesthetics. The rules of poetry which traditionally existed in the Arabic tradition came up against the application of Aristotle’s Poetics to that poetry. One of the interesting aspects of Islamic aesthetics is that it treated poetry as a logical form, albeit of a very low demonstrative value, along the continuum of logical forms which lie behind all our language and practices. This is explained in studies of both epistemology and logic . Logic came to play an enormous role in Islamic philosophy, and the idea that logic represents a basic set of techniques which lies behind what we think and what we do was felt to be very exciting and provocative. Many theologians who attacked philosophy were staunch defenders of logic as a tool for disputation, and Ibn Taymiyya is unusual in the strong critique which he provided of Aristotelian logic. He argued that the logic entails Aristotelian metaphysics, and so should be abandoned by anyone who wishes to avoid philosophical infection.
However, the general respect for logic provides the framework for the notion that there is a range of logical approaches which are available to different people, each of which is appropriate to different levels of society. For the theologian and the lawyer, for instance, dialectic is appropriate, since this works logically from generally accepted propositions to conclusions which are established as valid, but only within the limits set by those premises. This means that within the context of theology, for example, if we accept the truth of the Qur’an, then certain conclusions follow if we use the principles of theology; but if we do not accept the truth of the Qur’an, then the acceptability of those conclusions is dubious. Philosophers are distinguished from everyone else in that they are the only people who use entirely certain and universal premises, and so their conclusions have total universality as well as validity. When it comes to knowledge we find a similar contrast. Ordinary people can know something of what is around them and also of the spiritual nature of reality, but they are limited to the images and allegories of religion and the scope of their senses. Philosophers, by contrast, can attain much higher levels of knowledge through their application of logic and through their ability to perfect their understanding and establish contact with the principles which underlie the whole of reality.

5- Islamic philosophy in the modern world
After the death of Ibn Rushd, Islamic philosophy in the Peripatetic style went out of fashion in the Arab world, although the transmission of Islamic philosophy into Western Europe started at this time and had an important influence upon the direction which medieval and Renaissance Europe was to take. In the Persian-speaking world, Islamic philosophy has continued to follow a largely Illuminationist curriculum right up to today; but in the Arab world it fell into something of a decline, at least in its Peripatetic form, until the nineteenth century. Mystical philosophy, by contrast, continued to flourish, although no thinkers matched the creativity of Ibn al-‘Arabi or Ibn Sab‘in. Al-Afghani and Muhammad ‘Abduh sought to find rational principles which would establish a form of thought which is both distinctively Islamic and also appropriate for life in modern scientific societies, a debate which is continuing within Islamic philosophy today. Iqbal provided a rather eclectic mixture of Islamic and European philosophy, and some thinkers reacted to the phenomenon of modernity by developing Islamic fundamentalism. This resuscitated the earlier antagonism to philosophy by arguing for a return to the original principles of Islam and rejected modernity as a Western imperialist instrusion. The impact of Western scholarship on Islamic philosophy has not always been helpful, and Orientalism has sometimes led to an overemphasis of the dependence of Islamic philosophy on Greek thought, and to a refusal to regard Islamic philosophy as real philosophy. That is, in much of the exegetical literature there has been too much concern dealing with the historical conditions under which the philosophy was produced as compared with the status of the ideas themselves. While there are still many disputes concerning the ways in which Islamic philosophy should be pursued, as is the case with all kinds of philosophy, there can be little doubt about its major achievements and continuing significance.