The attempt to fuse religion and philosophy is difficult because there are no clear preconditions. Philosophers typically hold that one must accept the possibility of truth from any source and follow the argument wherever it leads. On the other hand, classical religious believers have a set of religious principles that they hold to be unchallengeable fact. Given these divergent goals and views, some hold that one cannot simultaneously be a philosopher and a true adherent of Islam, which is believed to be a revealed religion by its adherents. In this view, all attempts at synthesis ultimately fail.
However, others believe that a synthesis between Islam and philosophy is possible. One way to find a synthesis is to use philosophical arguments to prove that one's preset religious principles are true. This is a common technique found in the writings of many religious traditions, including Judaism, Christianity and Islam, but this is not generally accepted as true philosophy by philosophers. Another way to find a synthesis is to abstain from holding as true any religious principles of one's faith at all, unless one independently comes to those conclusions from a philosophical analysis. However, this is not generally accepted as being faithful to one's religion by adherents of that religion. A third, rarer and more difficult path is to apply analytical philosophy to one's own religion. In this case a religious person would also be a philosopher, by asking questions such as:
- What is the nature of God? How do we know that God exists?
- What is the nature of revelation? How do we know that God reveals his will to mankind?
- What is the nature of divinely guided Messengers vis à vis philosophers?
- What is the nature of Imamat or vicegerency of humans on earth?
- Which of our religious traditions must be interpreted literally?
- Which of our religious traditions must be interpreted allegorically?
- What must one actually believe to be considered a true adherent of our religion?
- How can one reconcile the findings of philosophy with religion?
- How can one reconcile the findings of science with religion?
- How can one reconcile the findings of math with religion
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. [Oliver Leaman, Routledge Encyclopedia of Philosophy]
Islamic philosophy as the name implies refers to philosophical activity within the Islamic milieu. The main sources of classical or early Islamic philosophy are the religion of Islam itself (especially ideas derived and interpreted from Quran), Greek philosophy which the early Muslims inherited as a result of conquests when Alexandria, Syria and Jundishapur came under Muslim rule, along with pre-Islamic Iranian and Indian philosophy. Many of the early philosophical debates centered around reconciling religion and reason, the latter exemplified by Greek philosophy.
Early and Classical Islamic philosophy
In early Islamic thought two main currents may be distinguished. The first is Kalam, that mainly dealt with theological questions, and the other is Falsafa, that was founded on the reception of Greek thought.
Independent minds exploiting the methods of ijtihad sought to investigate the doctrines of the Qur'an, which until then had been accepted in faith on the authority of divine revelation. One of first debates was that between partisan of the Qadar (Arabic: qadara, to have power), who affirmed free will, and the Jabarites (jabar, force, constraint), who maintained the belief in fatalism.
At the second century of the Hijra, a new movement arose in the theological school of Basra, Iraq. A pupil, Wasil ibn Ata, who was expelled from the school because his answers were contrary to then orthodox Islamic tradition and became leader of a new school, and systematized the radical opinions of preceding sects, particularly those of the Qadarites. This new school was called Mutazilite (from i'tazala, to separate oneself, to dissent). Its principal dogmas were three:
- God is an absolute unity, and no attribute can be ascribed to Him.
- Man is a free agent. It is on account of these two principles that the Mu'tazilites designate themselves the "Partisans of Justice and Unity".
- All knowledge necessary for the salvation of man emanates from his reason; humans could acquire knowledge before, as well as after, Revelation, by the sole light of reason. This fact makes knowledge obligatory upon all men, at all times, and in all places.
The Mutazilites, compelled to defend their principles against the orthodox Islam of their day, looked for support in philosophy, and are one of the first to pursue a rational theology called Ilm-al-Kalam (Scholastic theology); those professing it were called Mutakallamin. This appellation became the common name for all seeking philosophical demonstration in confirmation of religious principles. The first Mutakallamin had to debate both the orthodox and the non-Muslims, and they may be described as occupying the middle ground between those two parties. But subsequent generations were to large extent critical towards the Mutazilite school, especially after formation of the Asharite concepts.
From the ninth century onward, owing to Caliph al-Ma'mun and his successor, Greek philosophy was introduced among the Persians and Arabs, and the Peripatetic school began to find able representatives among them; such were Al-Kindi, Al-Farabi, Ibn Sina (Avicenna), and Ibn Rushd (Averroës), all of whose fundamental principles were considered as criticized by the Mutakallamin.
During the Abbasid caliphate a number of thinkers and scientists, many of them non-Muslims or heretical Muslims, played a role in transmitting Greek, Hindu, and other pre-Islamic knowledge to the Christian West. They contributed to making Aristotle known in Christian Europe. Three speculative thinkers, the two Persians al-Farabi and Avicenna and the Arab al-Kindi, combined Aristotelianism and Neoplatonism with other ideas introduced through Islam. They were considered by many as highly unorthodox and by some were even described as non-Islamic philosophers.
From Spain Arabic philosophic literature was translated into Hebrew and Latin, contributing to the development of modern European philosophy. The philosopher Moses Maimonides (a Jew born in Muslim Spain) was also important.
Some differences between Kalam and Falsafa
Aristotle attempted to demonstrate the unity of God; but from the view which he maintained, that matter was eternal, it followed that God could not be the Creator of the world. To assert that God's knowledge extends only to the general laws of the universe, and not to individual and accidental things, is tantamount to denying prophecy. One other point shocked the faith of the Mutakallamin — the theory of intellect. The Peripatetics taught that the human soul was only an aptitude — a faculty capable of attaining every variety of passive perfection — and that through information and virtue it became qualified for union with the active intellect, which latter emanates from God. To admit this theory would be to deny the immortality of the soul.
Wherefore the Mutakallamin had, before anything else, to establish a system of philosophy to demonstrate the creation of matter, and they adopted to that end the theory of atoms as enunciated by Democritus. They taught that atoms possess neither quantity nor extension. Originally atoms were created by God, and are created now as occasion seems to require. Bodies come into existence or die, through the aggregation or the sunderance of these atoms. But this theory did not remove the objections of philosophy to a creation of matter.
For, indeed, if it be supposed that God commenced His work at a certain definite time by His "will," and for a certain definite object, it must be admitted that He was imperfect before accomplishing His will, or before attaining His object. In order to obviate this difficulty, the Motekallamin extended their theory of the atoms to Time, and claimed that just as Space is constituted of atoms and vacuum, Time, likewise, is constituted of small indivisible moments. The creation of the world once established, it was an easy matter for them to demonstrate the existence of a Creator, and that God is unique, omnipotent, and omniscient.
Jewish philosophy in the Arab world in the classical period
The oldest Jewish religio-philosophical work preserved is that of Saadia Gaon (892-942), Emunot ve-Deot, "The Book of Beliefs and Opinions". In this work Saadia treats the questions that interested the Mutakallamin, such as the creation of matter, the unity of God, the divine attributes, the soul, etc. Saadia criticizes other philosophers severely. For Saadia there was no problem as to creation: God created the world ex nihilo, just as the Bible attests; and he contests the theory of the Mutakallamin in reference to atoms, which theory, he declares, is just as contrary to reason and religion as the theory of the philosophers professing the eternity of matter.
To prove the unity of God, Saadia uses the demonstrations of the Mutakallamin. Only the attributes of essence (sifat al-dhatia) can be ascribed to God, but not the attributes of action (sifat-al-fi'aliya). The soul is a substance more delicate even than that of the celestial spheres. Here Saadia controverts the Mutakallamin, who considered the soul an "accident" 'arad (compare Guide for the Perplexed i. 74), and employs the following one of their premises to justify his position: "Only a substance can be the substratum of an accident" (that is, of a non-essential property of things). Saadia argues: "If the soul be an accident only, it can itself have no such accidents as wisdom, joy, love," etc. Saadia was thus in every way a supporter of the Kalam; and if at times he deviated from its doctrines, it was owing to his religious views; just as the Jewish and Muslim Peripatetics stopped short in their respective Aristotelianism whenever there was danger of wounding orthodox religion.
Main protagonists of falsafa and their critics
The twelfth century saw the apotheosis of pure philosophy and the decline of the Kalam, which latter, being attacked by both the philosophers and the orthodox, perished for lack of champions. This supreme exaltation of philosophy may be attributed, in great measure, to Al-Ghazali (1005-1111) among the Persians, and to Judah ha-Levi (1140) among the Jews. It can be argued that the attacks directed against the philosophers by Ghazali in his work, "Tahafut al-Falasifa" (The Destruction of the Philosophers), not only produced, by reaction, a current favorable to philosophy, but induced the philosophers themselves to profit by his criticism. They thereafter made their theories clearer and their logic closer. The influence of this reaction brought forth the two greatest philosophers that the Islamic Peripatetic school ever produced, namely, Ibn Bajjah (Avempace) and Ibn Rushd (Averroes), both of whom undertook the defense of philosophy.
Since no idea and no literary or philosophical movement ever germinated on Persian or Arabian soil without leaving its impress on the Jews, the Persian Ghazali found an imitator in the person of Judah ha-Levi. This poet also took upon himself to free his religion from what he saw as the shackles of speculative philosophy, and to this end wrote the "Kuzari," in which he sought to discredit all schools of philosophy alike. He passes severe censure upon the Mutakallamin for seeking to support religion by philosophy. He says, "I consider him to have attained the highest degree of perfection who is convinced of religious truths without having scrutinized them and reasoned over them" ("Kuzari," v.). Then he reduced the chief propositions of the Mutakallamin, to prove the unity of God, to ten in number, describing them at length, and concluding in these terms: "Does the Kalam give us more information concerning God and His attributes than the prophet did?" (Ib. iii. and iv.) Aristotelianism finds no favor in Judah ha-Levi's eyes, for it is no less given to details and criticism; Neoplatonism alone suited him somewhat, owing to its appeal to his poetic temperament.
Ibn Rushd (or Ibn Roshd or Averroës), the contemporary of Maimonides, closed the first great philosophical era of the Muslims. The boldness of this great commentator of Aristotle aroused the full fury of the orthodox, who, in their zeal, attacked all philosophers indiscriminately, and had all philosophical writings committed to the flames. The theories of Ibn Rushd do not differ fundamentally from those of Ibn Bajjah and Ibn Tufail, who only follow the teachings of Ibn Sina and Al-Farabi. Like all Islamic Peripatetics, Ibn Rushd admits the hypothesis of the intelligence of the spheres and the hypothesis of universal emanation, through which motion is communicated from place to place to all parts of the universe as far as the supreme world—hypotheses which, in the mind of the Arabic philosophers, did away with the dualism involved in Aristotle's doctrine of pure energy and eternal matter. His ideas on the separation of philosophy and religion, further developed by the Averroist school of philosophy, were later influential in the development of modern secularism. Ibn Rushd is thus regarded as the founding father of secular thought in Western Europe.
But while Al-Farabi, Ibn Sina, and other Persian and Muslim philosophers hurried, so to speak, over subjects that trenched on religious dogmas, Ibn Rushd delighted in dwelling upon them with full particularity and stress. Thus he says, "Not only is matter eternal, but form is potentially inherent in matter; otherwise, it were a creation ex nihilo" (Munk, "Mélanges," p. 444). According to this theory, therefore, the existence of this world is not only a possibility, as Ibn Sina declared—in order to make concessions to the orthodox— but also a necessity.
Driven from the Islamic schools, Islamic philosophy found a refuge with the Jews, to whom belongs the honor of having transmitted it to the Christian world. A series of eminent men—such as the Ibn Tibbons, Narboni, Gersonides—joined in translating the Arabic philosophical works into Hebrew and commenting upon them. The works of Ibn Rushd especially became the subject of their study, due in great measure to Maimonides, who, in a letter addressed to his pupil Joseph ibn Aknin, spoke in the highest terms of Ibn Rushd's commentary.
It should be mentioned that this depiction of intellectual tradition in Islamic Lands is mainly dependent upon what West could understand (or was willing to understand) from this long era. In contrast, there are some historians and philosophers who do not agree with this account and describe this era in a completely different way. Their main point of dispute is on the influence of different philosophers on Islamic Philosophy, especially the comparative importance of eastern intellectuals such as Ibn Sina and of western thinkers such as Ibn Rushd. (For more discussion, refer to the History of Islamic Philosophy by Henry Corbin.)
Later Islamic philosophy
The death of Ibn Rushd effectively marks the end of a particular discipline of Islamic philosophy usually called the Peripatetic Arabic School, and philosophical activity declined significantly in western Islamic countries, namely in Spain and North Africa, though it persisted for much longer in the Eastern countries, in particular Iran and India.
Since the political power shift in Western Europe (Spain and Portugal) from Muslim to Christian control, the Muslims naturally did not practice philosophy in Western Europe. This also led to some loss of contact between the 'west' and the 'east' of the Islamic world. Muslims in the 'east' continued to do philosophy, as is evident from the works of Ottoman scholars and especially those living in Muslim kingdoms within the territories of present day Iran and India, such as Shah Waliullah and Ahmad Sirhindi. This fact has escaped most pre-modern historians of Islamic (or Arabic) philosophy. In addition, logic has continued to be taught in religious seminaries up to modern times.
After Ibn Rushd, there arose many later schools of Islamic Philosophy. We can mention just a few, such as the those founded by Ibn Arabi, Suhrawardi and Mulla Sadra. These new schools are of particular importance, as they are still active in the Islamic world.
Post-classical Islamic philosophy
Post-classical Islamic philosophers are usually divided into two main categories according to their affiliation with the Sunni and Shia denominations. Of course, there are many contemporary philosophers and thinkers such as Professor Nasr and Imam Musa Sadr who do not accept the importance of this classification. But there is a consensus that we can categorize this era according to the two main approaches: thinkers who mainly worked within the Shi’a tradition and thinkers who did not. If we accept this division then we can summarize each category as follows (it should be mentioned that this classification has many overlaps, is not very clear and precise).
Thinkers not primarily concerned with Shi’a beliefs:
- Abhari ابحرى
- Ibn Sab’in (d. 1268) ابن سبعين
- Kateb-e-Qazwini كاتب قزوينى
- Rashid-al-Din Fazlollah رشيدالدين فضل الله
- Qutb-al-din Razi قطب الدين رازى
- Opponents of Philosophy
- Ibn Taymiya (d. 1328) and his students ابن تيميه
- History of Philosophy
- Zakariya Qazwini زكرياى قزوينى
- Shams al-Din Mohamamd Amuli شمس الدين محمد آملى
- Ibn Khaldun (d. 1406) ابن خلدون
- Gnostic and Sufi thinkers
- Roz bahan Balqi Shirazi روزبهان بلقى شيرازى
- Farid al-Din Attar (Attar Nishpuri) عطار نيشابورى
- Umar Suhrawardi عمر سهروردى
- Ibn Arabi (d. 1240) & his School ابن عربى
- Najmeddin Kubra نجم الدين كبرى
- Simnani سمنانى
- Ali Hamedani على همدانى
- Mawlana Jalal al-Din Rumi مولانا
- Mahmud Shabestari & Shams al-Din Lahiji محمود شبسترى و شمس الدين لاهيجى
- Abd-al-karim Jili عبدالكريم جيلى
- Ne’mat-o-allah vali kermani نعمت الله ولى كرمانى
- Huroofi & Baktashi حروفى و بكتاشى
- Jami جامى
- Hossein Kashefi حسين كاشفى
- abd al-Qani Nablosi عبدالغنى نابلسى
- Noor ali Shah نورعلى شاه
- Zahbiyye ذهبيه
Thinkers primarily concerned with Shi’a beliefs:
- Nasir al-Din Tusi (d.1274) خواجه نصيرالدين توسي
- Isa’ili اسماعيليان
- Shahab al-Din Suhrawardi (d. 1191) and the Illumination School شهاب الدين سهروردى و مكتب اشراق
- Jaldaki جلدكى
- Sadr al-Din Dashtaki and the Shiraz School صدرالدين دشتكى و مكتب شيراز
- Mir Damad (d. 1631) and the Isfahan School ميرداماد و مكتب اصفهان
- Mir Fendereski and his students ميرفندرسكى
- Mulla Sadra (d. 1640) and the Transcendent Philosophy ملاصدرا و حكمت متعاليه
- Rajab Ali Tabrizi and his students رجب على تبريزى
- Qazi Sa’id Qumi قاضى سعيد قمى
- Tehran and Qom School مكتب تهران و قم
- Khorasan School مكتب خراسان
- Mulla Hadi Sabzevari and the Neyshabor School ملاهادى سبزوارى و مكتب نيشابور
Ibn Khaldun (1332-1406), in his Muqaddimah (the introduction to a seven volume analysis of universal history), advanced social philosophy in formulating theories of social cohesion and social conflict.
Modern Islamic philosophy
The tradition of Islamic Philosophy is still very much alive today despite the belief in many Western circles that this tradition ceased after the golden ages of Suhrawardi’s Hikmat al-Ishraq (Illumination Philosophy) or, at the latest, Mulla Sadra’s Hikmat-e-Mota’aliye or Transcendent (Exalted) Philosophy. Another unavoidable name is Allama Muhammad Iqbal who reshaped and revitalized Islamic philosophy amongst the Muslims of the Indian sub-continent in the early 20th century. Beside his Urdu and Persian poetical work, The Reconstruction of Religious Thought in Islam  is a milestone in the modern political philosophy of Islam.
In contemporary Islamic Lands, the teaching of hikmat or hikmah has continued and flourished.
Among the traditional masters of Islamic philosophy most active during the past two decades may be mentioned
- the Iranian علامه طباطبائى or Allameh Tabatabaei, the author of numerous works including the twenty seven-volume Quranic commentary al-Mizan (الميزان),
- Sayyid Abul-Hasan Rafi’i Qazwini (سيد ابوالحسن رفيعى قزوينى) the great master of Mulla Sadra's school who has written a few treasured works but has trained many outstanding students such as Sayyid Jalal-al-Din Ashtiyani (جلال الدين آشتيانى), who has studied with both him and Allamah Tabatabai, and
- Allamah Muhammad Salih Ha’iri Simnanin, the most loyal follower of Peripatetic philosophy and opposed to Mulla Sadra's school.
The younger traditional scholars who have been most active recently in Islamic Philosophy include
- Mirza Mahdi Ha‘iri, the only one of the traditional class of hakims with an extensive experience of the West and author of Ilm-I Kulli and Kavoshha-ye Aqli-Nazari;
- Murtaza Motahhari, the best student of Allamah Tabatabai, a martyr of the Iran Islamic Revolution; and
- Seyyed Hossein Nasr.
- Imran Nazar Hosein.- Author of Jerusalem in the Quran
- In Malaysia, Syed Muhammad Naquib al-Attas is a prominent metaphysical thinker.;
- One of the prominent Islamic thinkers of the twenty first century is Abd'allah ibn Zubair, author of Muktassar Falsafa (The Parables of Sophism) first published in 1977 with the aide of Professor Hamid Mahmud, Maulana Maududi and Major Bashiruddin.;
- Islamic science
- Modern Islamic philosophy
- Islamic Institute of Philosophy
- The concept of Tai al-Ardh (teleportation)
- History of Islamic Philosophy, by Henry Corbin, ISBN 0-710-30416-1
- History of Islamic Philosophy (Routledge History of World Philosophies) by Seyyed Hossein Nasr and Oliver Leaman [ed.]
- History of Islamic Philosophy by Majid Fahkry
- Islamic Philosophy by Oliver Leaman https://www.rep.routledge.com/article/H057
- The Study of Islamic Philosophy by Ibrahim Bayyumi Madkour
- Falsafatuna (Our Philosophy) by Muhammad Baqir al-Sadr
- Dictionary of Islamic Philosophical Terms
- Islamic Ethics and Philosophy Dictionary
- The meaning and concept of philosophy in Islam by Hossein Nasr
- Islamic Philosophy Online
- History of Philosophy in Islam by T. J. De Boer(1903)
- The Study of Islamic Philosophy
- History of Islamic Philosophy - The Parables of Sophism - Abd'allah ibn Zubair
- Islamic Philosophy From the Routledge Encyclopedia of Philosophy
- Abdel Wahab El Messeri. Episode 21: Ibn Rushd, Everything you wanted to know about Islam but were afraid to ask, Philosophia Islamica.
- Fauzi M. Najjar (Spring, 1996). The debate on Islam and secularism in Egypt, Arab Studies Quarterly (ASQ).
- Majid Fakhry (2001). Averroes: His Life, Works and Influence. Oneworld Publications. ISBN 1851682694.