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Origin
Muhammad
The life of Muhammad or sira which generated both the Qur'an (revelation) and hadith (his daily utterances and discourses on social and legal matters), during which philosophy was defined by Muslims as consisting in acceptance or rejection of his message. Together the sira and hadith constitute the sunnah and are validated by isnad ("backing") to determine the likely truth of the report of any given saying of Muhammad. Key figures are Imam Jaffar as-Sadegh (AS), Imam Bukhari, Imam Muslim, Al-Tirmidhi, Ibn Majah, Abu Dawud and Al-Nasa'i. Each sifted through literally millions of hadith to accept a list of under 10,000. This work, which was not completed until the 10th century, began shortly after The Farewell Sermon in 631, after which Muhammad could not mediate disputes. After his death Abu Bakr began to collect all fragments of his sayings.
Branches
Kalam
With Kalam, questions about the sira and hadith, as well as science (Islamic science) and law (fiqh and sharia), began to be investigated beyond the scope of Muhammad's beliefs. This period is characterized by emergence of ijtihad and the first fiqh. As the Sunnah became published and accepted, philosophy separate from Muslim theology was discouraged due to a lack of participants. During this period, traditions similar to Socratic method began to evolve, but philosophy remained subordinate to religion. "Kalam" generally referred to the Islamic tradition of seeking theological principles through dialectic.
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'tazilities 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 Mutazilities, 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.
Falsafa
From the 9th century onwards, owing to Caliph al-Ma'mun and his successor, Greek philosophy and Hellenistic philosophy were introduced among the Persians and Arabs, and the Peripatetic and Neoplatonic schools began to find able representatives among them; such were al-Kindi, al-Farabi, Avicenna (Ibn Sina), and Averroes (Ibn Rushd), all of whose fundamental principles were considered as criticized by the Mutakallamin.
During the Abbasid caliphate a number of thinkers and scientists, some of them heterodox Muslims or non-Muslims, played a role in transmitting Greek, Hellenistic, Indian 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 a few even described them as non-Islamic philosophers.
From Spain Arabic philosophic literature was translated into Hebrew and Latin, contributing to the development of modern European philosophy. The philosophers Moses Maimonides (a Jew born in Muslim Spain) and Ibn Khaldun (born in modern-day Tunisia), the father of sociology and historiography, were also important philosophers, though the latter did not identify himself as a falsafa, but rather a kalam author.
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.
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 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.[2][3] Ibn Rushd is thus regarded as the founding father of secular thought in Western Europe.[4]
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 ben Judah, 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.[5]
Judeo-Islamic philosophy
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.
Schools
Avicennism
| Avicenna |
|---|
| Avicennism |
| The Canon of Medicine |
| The Book of Healing |
| Hayy ibn Yaqdhan |
| Criticism of Avicennian philosophy |
In the Islamic Golden Age, due to Avicenna's (Ibn Sina's) successful reconciliation between Aristotelianism and Neoplatonism along with Kalam, Avicennism eventually became the leading school of Islamic philosophy by the 12th century. Avicenna had become a central authority on philosophy by then, and several scholars in the 12th century commented on his strong influence at the time:[6]
"People nowadays [believe] that truth is whatever [Ibn Sina] says, that it is inconceivable for him to err, and that whoever contradicts him in anything he says cannot be rational."
Avicennism was also infuential in medieval Europe, particularly his doctrines on the nature of the soul and his existence-essence distinction, along with the debates and censure that they raised in scholastic Europe. This was particularly the case in Paris, where Avicennism was later proscribed in 1210. Nevertheless, his psychology and theory of knowledge influenced William of Auvergne and Albertus Magnus, and his metaphysics had an impact on the thought of Thomas Aquinas.[7]
Averroism
Averroes (Ibn Rushd) is most famous for his commentaries on Aristotle's works and for writing The Incoherence of the Incoherence in which he defended the falasifa against al-Ghazali's The Incoherence of the Philosophers. While he had very little influence in the Islamic world, which was then dominated by Avicennian philosophy and Ash'ari theology, Averroism became very infuential in medieval Europe, especially among the Scholastics. Averroism eventually led to the development of modern secularism,[2][3] for which Ibn Rushd is considered as the founding father of secular thought in Western Europe.[4]
Ethics
Environmental philosophy
Perhaps due to resource scarcity in most Islamic nations, there was an emphasis on limited (and some claim also sustainable) use of natural capital, i.e. producing land. Traditions of haram and hima and early urban planning were expressions of strong social obligations to stay within carrying capacity and to preserve the natural environment as an obligation of khalifa or "stewardship".[8]
Muhammad is considered a pioneer of environmentalism for his teachings on environmental preservation. His hadiths on agriculture and environmental philosophy were compiled in the "Book of Agriculture" of the Sahih Bukhari, which included the following saying:[9]
"There is none amongst the believers who plants a tree, or sows a seed, and then a bird, or a person, or an animal eats thereof, but it is regarded as having given a charitable gift [for which there is great recompense]."[10]
Several such statements concerning the environment are also found in the Qur'an, such as the following:[11]
"And there is no animal in the earth nor bird that flies with its two wings, but that they are communities like yourselves."[12]
The earliest known treatises dealing with environmentalism and environmental science, especially pollution, were Arabic medical treatises written by al-Kindi, Qusta ibn Luqa, al-Razi, Ibn Al-Jazzar, al-Tamimi, al-Masihi, Avicenna, Ali ibn Ridwan, Ibn Jumay, Isaac Israeli ben Solomon, Abd-el-latif, Ibn al-Quff, and Ibn al-Nafis. Their works covered a number of subjects related to pollution such as air pollution, water pollution, soil contamination, municipal solid waste mishandling, and environmental impact assessments of certain localities.[13] Cordoba, al-Andalus also had the first waste containers and waste disposal facilities for litter collection.[14]
Medical ethics
The ethical standards of Muslim physicians was first laid down in the 9th century by Ishaq bin Ali Rahawi, who wrote the Adab al-Tabib (Conduct of a Physician), the first treatist dedicated to medical ethics. He regarded physicians as "guardians of souls and bodies", and wrote twenty chapters on various topics related to medical ethics, including:[15]
- What the physician must avoid and beware of
- The manners of visitors
- The care of remedies by the physician
- The dignity of the medical profession
- The examination of physicians
- The removal of corruption among physicians
Humanism
Many medieval Muslim thinkers pursued humanistic, rational and scientific discourses in their search for knowledge, meaning and values. A wide range of Islamic writings on love poetry, history and philosophical theology show that medieval Islamic thought was open to the humanistic ideas of individualism, occasional secularism, skepticism and liberalism.[16]
Another reason the Islamic world flourished during the Middle Ages was an early emphasis on freedom of speech, as summarized by al-Hashimi (a cousin of Caliph al-Ma'mun) in the following letter to one of the religious opponents he was attempting to convert through reason:[17]
"Bring forward all the arguments you wish and say whatever you please and speak your mind freely. Now that you are safe and free to say whatever you please appoint some arbitrator who will impartially judge between us and lean only towards the truth and be free from the empery of passion, and that arbitrator shall be Reason, whereby God makes us responsible for our own rewards and punishments. Herein I have dealt justly with you and have given you full security and am ready to accept whatever decision Reason may give for me or against me. For "There is no compulsion in religion" (Qur'an 2:256) and I have only invited you to accept our faith willingly and of your own accord and have pointed out the hideousness of your present belief. Peace be with you and the blessings of God!"
Evolution
Early Muslim scientists and philosophers developed theories on evolution, and the transmutation of species, which were widely taught in medieval Islamic schools. John William Draper, a contemporary of Charles Darwin, wrote the following on what he called the "Mohammedan theory of evolution" in 1878:[18]
"Sometimes, not without surprise, we meet with ideas which we flatter ourselves have originated in our own times. Thus our modern doctrines of evolution and development were taught in their schools. In fact, they carried them much farther than we are disposed to do, extending them even to inorganic or mineral things. The fundamental principle of alchemy was the natural process of development of metalline bodies."[19]
Al-Jahiz and the struggle for existence
The Mu'tazili scientist and philosopher al-Jahiz (c. 776-869) was the first of the Muslim biologists and philosophers to develop an early theory of evolution. He speculated on the influence of the environment on animals, considered the effects of the environment on the likelihood of an animal to survive, and first described the struggle for existence, a precursor to natural selection.[20][21] Al-Jahiz wrote the following on the struggle for existence in his work, Book of Animals:
"Animals engage in a struggle for existence; for resources, to avoid being eaten and to breed. Environmental factors influence organisms to develop new characteristics to ensure survival, thus transforming into new species. Animals that survive to breed can pass on their successful characteristics to offspring."[22]
Ibn Miskawayh and the Brethren of Purity
Ibn Miskawayh's al-Fawz al-Asghar and the Brethren of Purity's Encyclopedia of the Brethren of Purity (The Epistles of Ikhwan al-Safa) developed theories on evolution that later had an influence on Charles Darwin and his inception of Darwinism. Muhammad Hamidullah describes their evolutionary ideas as follows:
"[These books] state that God first created matter and invested it with energy for development. Matter, therefore, adopted the form of vapour which assumed the shape of water in due time. The next stage of development was mineral life. Different kinds of stones developed in course of time. Their highest form being mirjan (coral). It is a stone which has in it branches like those of a tree. After mineral life evolves vegetation. The evolution of vegetation culminates with a tree which bears the qualities of an animal. This is the date-palm. It has male and female genders. It does not wither if all its branches are chopped but it dies when the head is cut off. The date-palm is therefore considered the highest among the trees and resembles the lowest among animals. Then is born the lowest of animals. It evolves into an ape. This is not the statement of Darwin. This is what Ibn Maskawayh states and this is precisely what is written in the Epistles of Ikhwan al-Safa. The Muslim thinkers state that ape then evolved into a lower kind of a barbarian man. He then became a superior human being. Man becomes a saint, a prophet. He evolves into a higher stage and becomes an angel. The one higher to angels is indeed none but God. Everything begins from Him and everything returns to Him."[23]
Eloise Hart also describes the evolutionary thought in the Encyclopedia of the Brethren of Purity as follows:
"Another section describes the creation of worlds and the evolution of life in details that would have impressed Darwin. It explains how manifestation unfolds through successive layers, or stratified planes down to the mineral kingdom. Where, in this lowest kingdom, the most developed mineral entities live within its highest strata and blend imperceptibly into the next higher or vegetable kingdom. Likewise the vegetable kingdom contacts, at its highest level, the animal kingdom, whose culmination is man. The most evolved men contact higher spheres and, standing between the angelic and animal orders, serve on earth as vicegerents of God."[24]
English translations of the Encyclopedia of the Brethren of Purity were available from 1812,[25] while Arabic manuscripts of the al-Fawz al-Asghar and The Epistles of Ikhwan al-Safa were also available at the University of Cambridge by the 19th century. These works likely had an influence on 19th century evolutionists, and possibly Charles Darwin, who may have been a student of Arabic.[23][24]
Al-Khazini and the transmutation of species
In the 12th century, al-Khazini wrote the following on how evolution in alchemy and biology were perceived by natural philosophers and common people in the Islamic world at the time:
"When common people hear from natural philosophers that gold is a body which has attained to perfection of maturity, to the goal of completeness, they firmly believe that it is something which has gradually come to that perfection by passing through the forms of all other metallic bodies, so that its gold nature was originally lead, afterward it became tin, then brass, then silver, and finally reached the development of gold; not knowing that the natural philosophers mean, in saying this, only something like what they mean when they speak of man, and attribute to him a completeness and equilibrium in nature and constitution - not that man was once a bull, and was changed into an ass, and afterward into a horse, and after that into an ape, and finally became a man."[19]
Other supporters
The Ash'ari polymath Ibn al-Haytham later wrote a book in which he argued for evolutionism (although not natural selection), and numerous other Islamic scholars and scientists, including the polymaths Abū Rayhān al-Bīrūnī, al-Khazini, Nasir al-Din Tusi, and Ibn Khaldun, discussed and developed these ideas. Translated into Latin, these works began to appear in the West after the Renaissance and may have had an impact on Western philosophy and science.
Logic
In early Islamic philosophy, logic played an important role. Islamic law placed importance on formulating standards of argument, which gave rise to a novel approach to logic in Kalam, but this approach was later displaced by ideas from Greek philosophy and Hellenistic philosophy with the rise of the Mu'tazili philosophers, who highly valued Aristotle's Organon. The works of Hellenistic-influenced Islamic philosophers were crucial in the reception of Aristotelian logic in medieval Europe, along with the commentaries on the Organon by Averroes. The works of al-Farabi, Avicenna, al-Ghazali and other Muslim logicians who often criticized and corrected Aristotelian logic and introduced their own forms of logic, also played a central role in the subsequent development of European logic during the Renaissance.
According to the Routledge Encyclopedia of Philosophy:
"For the Islamic philosophers, logic included not only the study of formal patterns of inference and their validity but also elements of the philosophy of language and even of epistemology and metaphysics. Because of territorial disputes with the Arabic grammarians, Islamic philosophers were very interested in working out the relationship between logic and language, and they devoted much discussion to the question of the subject matter and aims of logic in relation to reasoning and speech. In the area of formal logical analysis, they elaborated upon the theory of terms, propositions and syllogisms as formulated in Aristotle's Categories, De interpretatione and Prior Analytics. In the spirit of Aristotle, they considered the syllogism to be the form to which all rational argumentation could be reduced, and they regarded syllogistic theory as the focal point of logic. Even poetics was considered as a syllogistic art in some fashion by most of the major Islamic Aristotelians."
Important developments made by Muslim logicians included the development of "Avicennian logic" as a replacement of Aristotelian logic. Avicenna's system of logic was responsible for the introduction of hypothetical syllogism, temporal modal logic and inductive logic. Other important developments in early Islamic philosophy include the development of a strict science of citation, the isnad or "backing", and the development of a scientific method of open inquiry to disprove claims, the ijtihad, which could be generally applied to many types of questions.
Logic in Islamic law and theology
Early forms of analogical reasoning, inductive reasoning and categorical syllogism were introduced in Fiqh (Islamic jurisprudence), Sharia (Islamic law) and Kalam (Islamic theology) from the 7th century with the process of Qiyas, before the Arabic translations of Aristotle's works. Later during the Islamic Golden Age, there was a logical debate among Islamic philosophers, logicians and theologians over whether the term Qiyas refers to analogical reasoning, inductive reasoning or categorical syllogism. Some Islamic scholars argued that Qiyas refers to inductive reasoning, which Ibn Hazm (994-1064) disagreed with, arguing that Qiyas does not refer to inductive reasoning, but refers to categorical syllogism in a real sense and analogical reasoning in a metaphorical sense. On the other hand, al-Ghazali (1058-1111) (and in modern times, Abu Muhammad Asem al-Maqdisi) argued that Qiyas refers to analogical reasoning in a real sense and categorical syllogism in a metaphorical sense. Other Islamic scholars at the time, however, argued that the term Qiyas refers to both analogical reasoning and categorical syllogism in a real sense.[26]
Aristotelian logic
The first original Arabic writings on logic were produced by al-Kindi (Alkindus) (805–873), who produced a summary on earlier logic up to his time. The first writings on logic with non-Aristotelian elements was produced by al-Farabi (Alfarabi) (873–950), who discussed the topics of future contingents, the number and relation of the categories, the relation between logic and grammar, and non-Aristotelian forms of inference. He is also credited for categorizing logic into two separate groups, the first being "idea" and the second being "proof."[27]
Averroes (1126–98) was the last major logician from al-Andalus, who wrote the most elaborate commentaries on Aristotelian logic.
Avicennian logic
Avicenna (980-1037) developed his own system of logic known as "Avicennian logic" as an alternative to Aristotelian logic. By the 12th century, Avicennian logic had replaced Aristotelian logic as the dominant system of logic in the Islamic world.[28]
The first criticisms of Aristotelian logic were written by Avicenna (980–1037), who produced independent treatises on logic rather than commentaries. He criticized the logical school of Baghdad for their devotion to Aristotle at the time. He investigated the theory of definition and classification and the quantification of the predicates of categorical propositions, and developed an original theory on "temporal modal" syllogism. Its premises included modifiers such as "at all times", "at most times", and "at some time".
While Avicenna (980-1037) often relied on deductive reasoning in philosophy, he used a different approach in medicine. Ibn Sina contributed inventively to the development of inductive logic, which he used to pioneer the idea of a syndrome. In his medical writings, Avicenna was the first to describe the methods of agreement, difference and concomitant variation which are critical to inductive logic and the scientific method.[29]
Ibn Hazm (994-1064) wrote the Scope of Logic, in which he stressed on the importance of sense perception as a source of knowledge.[30] Al-Ghazali (Algazel) (1058–1111) had an important influence on the use of logic in theology, making use of Avicennian logic in Kalam.[27] Despite the logical sophistication of al-Ghazali, the rise of the Ash'ari school in the from the 12th century slowly suffocated original work on logic in much of the Islamic world, though logic continued to be studied in some Islamic regions such as Persia and the Levant.
Fakhr al-Din al-Razi (b. 1149) criticised Aristotle's "first figure" and developed a form of inductive logic, foreshadowing the system of inductive logic developed by John Stuart Mill (1806-1873). Systematic refutations of Greek logic were written by the Illuminationist school, founded by Shahab al-Din Suhrawardi (1155-1191), who developed the idea of "decisive necessity", an important innovation in the history of logical philosophical speculation.[30] Another systematic refutation of Greek logic was written by Ibn Taymiyyah (1263-1328), who wrote the ar-Radd 'ala al-Mantiqiyyin (Refutation of Greek Logicians), in which he gave a proof for induction being the only true form of argument, which had an important influence on the development of the scientific method of observation and experimentation.[30]
Metaphysics
Cosmological and ontological arguments
Avicenna's proof for the existence of God was the first ontological argument, which he proposed in the Metaphysics section of The Book of Healing.[31][32] This was the first attempt at using the method of a priori proof, which utilizes intuition and reason alone. Avicenna's proof of God's existence is unique in that it can be classified as both a cosmological argument and an ontological argument. "It is ontological insofar as ‘necessary existence’ in intellect is the first basis for arguing for a Necessary Existent". The proof is also "cosmological insofar as most of it is taken up with arguing that contingent existents cannot stand alone and must end up in a Necessary Existent."[33]
Distinction between essence and existence
Islamic philosophy, imbued as it is with Islamic theology, distinguishes more clearly than Aristotelianism the difference between essence and existence. Whereas existence is the domain of the contingent and the accidental, essence endures within a being beyond the accidental. This was first described by Avicenna's works on metaphysics, who was himself influenced by al-Farabi.
Some orientalists (or those particularly influenced by Thomist scholarship) argued that Avicenna was the first to view existence (wujud) as an accident that happens to the essence (mahiyya). However, this aspect of ontology is not the most central to the distinction that Avicenna established between essence and existence. One cannot therefore make the claim that Avicenna was the proponent of the concept of essentialism per se, given that existence (al-wujud) when thought of in terms of necessity would ontologically translate into a notion of the Necessary-Existent-due-to-Itself (wajib al-wujud bi-dhatihi), which is without description or definition, and particularly without quiddity or essence (la mahiyya lahu). Consequently, Avicenna's ontology is 'existentialist' when accounting for being qua existence in terms of necessity (wujub), while it is 'essentialist' in terms of thinking about being qua existence (wujud) in terms of contingency qua possibility (imkan; or mumkin al-wujud: contingent being).[34]
Some argue that Avicenna anticipated Frege and Bertrand Russell in "holding that existence is an accident of accidents" and also anticipated Alexius Meinong's "view about nonexistent objects."[35] He also provided early arguments for "a 'necessary being' as cause of all other existents."[36]
The idea of "essence precedes existence" is a concept which dates back to Avicenna[37] and his school of Avicennism as well as Shahab al-Din Suhrawardi[38] and his Illuminationist philosophy. The opposite idea of "Existence precedes essence" was thus developed in the works of Averroes[37]
More careful approaches are needed in terms of thinking about philosophers (and theologians) in Islam in terms of phenomenological methods of investigation in ontology (or onto-theology), or by way of comparisons that are made with Heidegger's thought and his critique of the history of metaphysics.[39]
Resurrection
Ibn al-Nafis wrote the Theologus Autodidactus as a defense of "the system of Islam and the Muslims' doctrines on the missions of Prophets, the religious laws, the resurrection of the body, and the transitoriness of the world." The book presents rational arguments for bodily resurrection and the immortality of the human soul, using both demonstrative reasoning and material from the hadith corpus as forms of evidence. Later Islamic scholars viewed this work as a response to Avicenna's metaphysical argument on spiritual resurrection (as opposed to bodily resurrection), which was earlier criticized by al-Ghazali.[40]
Soul and spirit
The Muslim physician-philosophers, Avicenna and Ibn al-Nafis, developed their own theories on the soul. They both made a distinction between the soul and the spirit, and in particular, the Avicennian doctrine on the nature of the soul was influential among the Scholastics. Some of Avicenna's views on the soul included the idea that the immortality of the soul is a consequence of its nature, and not a purpose for it to fulfill. In his theory of "The Ten Intellects", he viewed the human soul as the tenth and final intellect.
Avicenna generally supported Aristotle's idea of the soul originating from the heart, whereas Ibn al-Nafis on the other hand rejected this idea and instead argued that the soul "is related to the entirety and not to one or a few organs." He further criticized Aristotle's idea that every unique soul requires the existence of a unique source, in this case the heart. Ibn al-Nafis concluded that "the soul is related primarily neither to the spirit nor to any organ, but rather to the entire matter whose temperament is prepared to receive that soul" and he defined the soul as nothing other than "what a human indicates by saying ‘I’."[41]
Thought experiments
- Further information: Avicennism - Thought experiments on self-consciousness
While he was imprisoned in the castle of Fardajan near Hamadhan, Avicenna wrote his famous "Floating Man" thought experiment to demonstrate human self-awareness and the substantiality of the soul. He referred to the living human intelligence, particularly the active intellect, which he believed to be the hypostasis by which God communicates truth to the human mind and imparts order and intelligibility to nature. His "Floating Man" thought experiment tells its readers to imagine themselves suspended in the air, isolated from all sensations, which includes no sensory contact with even their own bodies. He argues that, in this scenario, one would still have self-consciousness. He thus concludes that the idea of the self is not logically dependent on any physical thing, and that the soul should not be seen in relative terms, but as a primary given, a substance.[42]
This argument was later refined and simplified by René Descartes in epistemic terms when he stated: "I can abstract from the supposition of all external things, but not from the supposition of my own consciousness."[42]
Truth
In metaphysics, Avicenna (Ibn Sina) defined truth as:
"What corresponds in the mind to what is outside it."[43]
Avicenna elaborated on his definition of truth in his Metaphysics:
"The truth of a thing is the property of the being of each thing which has been established in it."[44]
In his Quodlibeta, Thomas Aquinas wrote a commentary on Avicenna's definition of truth in his Metaphysics and explained it as follows:
"The truth of each thing, as Avicenna says in his Metaphysica, is nothing else than the property of its being which has been established in it. So that is called true gold which has properly the being of gold and attains to the established determinations of the nature of gold. Now, each thing has properly being in some nature because it stands under the complete form proper to that nature, whereby being and species in that nature is."[44]
Early Islamic political philosophy emphasized an inexorable link between science and religion and emphsized the process of ijtihad to find truth.
Ibn al-Haytham (Alhacen) reasoned that to discover the truth about nature, it is necessary to eliminate human opinion and error, and allow the universe to speak for itself.[45] In his Aporias against Ptolemy, Ibn al-Haytham further wrote the following comments on truth:
"Truth is sought for itself [but] the truths, [he warns] are immersed in uncertainties [and the scientific authorities (such as Ptolemy, whom he greatly respected) are] not immune from error..."[46]
"Therefore, the seeker after the truth is not one who studies the writings of the ancients and, following his natural disposition, puts his trust in them, but rather the one who suspects his faith in them and questions what he gathers from them, the one who submits to argument and demonstration, and not to the sayings of a human being whose nature is fraught with all kinds of imperfection and deficiency. Thus the duty of the man who investigates the writings of scientists, if learning the truth is his goal, is to make himself an enemy of all that he reads, and, applying his mind to the core and margins of its content, attack it from every side. He should also suspect himself as he performs his critical examination of it, so that he may avoid falling into either prejudice or leniency."[46]
"I constantly sought knowledge and truth, and it became my belief that for gaining access to the effulgence and closeness to God, there is no better way than that of searching for truth and knowledge."[47]
Philosophy of science
- See also: Islamic science
Scientific method
The pioneering development of the scientific method by the Arab Ash'ari polymath Ibn al-Haytham (Alhacen) was an important contribution to the philosophy of science. In the Book of Optics, his scientific method was very similar to the modern scientific method and consisted of the following procedures:[45]
- Observation
- Statement of problem
- Formulation of hypothesis
- Testing of hypothesis using experimentation
- Analysis of experimental results
- Interpretation of data and formulation of conclusion
- Publication of findings
In The Model of the Motions, Ibn al-Haytham also describes an early version of Occam's razor, where he employs only minimal hypotheses regarding the properties that characterize astronomical motions, as he attempts to eliminate from his planetary model the cosmological hypotheses that cannot be observed from Earth.[48]
In his Aporias against Ptolemy, Ibn al-Haytham commented on the difficulty of attaining scientific knowledge:
"Truth is sought for itself [but] the truths, [he warns] are immersed in uncertainties [and the scientific authorities (such as Ptolemy, whom he greatly respected) are] not immune from error..."[46]
He held that the criticism of existing theories — which dominated this book — holds a special place in the growth of scientific knowledge:
"Therefore, the seeker after the truth is not one who studies the writings of the ancients and, following his natural disposition, puts his trust in them, but rather the one who suspects his faith in them and questions what he gathers from them, the one who submits to argument and demonstration, and not to the sayings of a human being whose nature is fraught with all kinds of imperfection and deficiency. Thus the duty of the man who investigates the writings of scientists, if learning the truth is his goal, is to make himself an enemy of all that he reads, and, applying his mind to the core and margins of its content, attack it from every side. He should also suspect himself as he performs his critical examination of it, so that he may avoid falling into either prejudice or leniency."[46]
Ibn al-Haytham attributed his experimental scientific method and scientific skepticism to his Islamic faith. He believed that human beings are inherently flawed and that only God is perfect. He reasoned that to discover the truth about nature, it is necessary to eliminate human opinion and error, and allow the universe to speak for itself.[45] In The Winding Motion, Ibn al-Haytham further wrote that faith should only apply to prophets of Islam and not to any other authorities, in the following comparison between the Islamic prophetic tradition and the demonstrative sciences:
"From the statements made by the noble Shaykh, it is clear that he believes in Ptolemy's words in everything he says, without relying on a demonstration or calling on a proof, but by pure imitation (taqlid); that is how experts in the prophetic tradition have faith in Prophets, may the blessing of God be upon them. But it is not the way that mathematicians have faith in specialists in the demonstrative sciences."[49]
Ibn al-Haytham described his search for truth and knowledge as a way of leading him closer to God:
"I constantly sought knowledge and truth, and it became my belief that for gaining access to the effulgence and closeness to God, there is no better way than that of searching for truth and knowledge."[47]
His contemporary Abū Rayhān al-Bīrūnī also introduced an early scientific method in nearly every field of inquiry he studied. For example, in his treatise on mineralogy, Kitab al-Jamahir (Book of Precious Stones), he is "the most exact of experimental scientists", while in the introduction to his study of India, he declares that "to execute our project, it has not been possible to follow the geometric method" and develops comparative sociology as a scientific method in the field.[50] He was also responsible for introducing the experimental method into mechanics,[51] the first to conduct elaborate experiments related to astronomical phenomena,[52] and a pioneer of experimental psychology.[53]
Unlike his contemporary Avicenna's scientific method where "general and universal questions came first and led to experimental work", al-Biruni developed scientific methods where "universals came out of practical, experimental work" and "theories are formulated after discoveries."[50] During his debate with Avicenna on natural philosophy, al-Biruni made the first real distinction between a scientist and a philosopher, referring to Avicenna as a philosopher and considering himself to be a mathematical scientist.[54]
Al-Biruni's scientific method was similar to the modern scientific method in many ways, particularly his emphasis on repeated experimentation. Biruni was concerned with how to conceptualize and prevent both systematic errors and random errors, such as "errors caused by the use of small instruments and errors made by human observers." He argued that if instruments produce random errors because of their imperfections or idiosyncratic qualities, then multiple observations must be taken, analyzed qualitatively, and on this basis, arrive at a "common-sense single value for the constant sought", whether an arithmetic mean or a "reliable estimate."[55]
Experimental medicine
Avicenna (Ibn Sina) is considered the father of modern medicine,[56] for his introduction of systematic experimentation and quantification into the study of physiology,[57] the introduction of experimental medicine and clinical trials,[58] the experimental use and testing of drugs, and a precise guide for practical experimentation in the process of discovering and proving the effectiveness of medical substances,[59] in h