In philosophy, as in science, Islam borrowed from Christian Syria the legacy of pagan Greece, and returned it through Moslem Spain to Christian Europe. Many influences, of course, ran together to produce the intellectual rebellion of the Mutazilites, and the philosophies of al-Kindi, al-Farabi, Avicenna, and Averroës. Hindu speculations came in through Ghazni and Persia; Zoroastrian and Jewish eschatology played some minor role; and Christian heretics had stirred the air of the Near East with debate on the attributes of God, the nature of Christ and the Logos, predestination and free will, revelation and reason. But the yeast that caused the ferment of thought in Moslem Asia—as in Renaissance Italy—was the rediscovery of Greece. Here, through however imperfect translations of apocryphal texts, a new world appeared: one in which men had reasoned fearlessly about everything, unchecked by sacred scriptures, and had conceived a cosmos not of divine whimsy and incalculable miracle, but of majestic and omnipresent law. Greek logic, fully conveyed through Aristotle’s Organon, came like an intoxication to Moslems now gifted with leisure to think; here were the terms and implements they needed for thought; now for three centuries Islam played the new game of logic, drunk like the Athenian youth of Plato’s time with the “dear delight” of philosophy. Soon the whole edifice of Mohammedan dogma began to tremble and crack, as Greek orthodoxy had melted under the Sophists’ eloquence, as Christian orthodoxy would wince and wilt under the blows of the Encyclopedists and the whips of Voltaire’s wit.
What might be called the Moslem Enlightenment had its proximate origin in a strange dispute. Was the Koran eternal or created? Philo’s doctrine of the Logos as the timeless Wisdom of God; the Fourth Gospel’s identification of Christ with the Logos, the Divine Word or Reason, that was “in the beginning … was God,” and “without which was not anything made that was made”;53 the Gnostic and Neoplatonic personification of Divine Wisdom as the agent of creation; the Jewish belief in the eternity of the Torah—all conspired to beget in orthodox Islam a correlative view that the Koran had always existed in the mind of Allah, and that only its revelation to Mohammed was an event in time. The first expression of philosophy in Islam (c. 757) was the growth of a school of “Mutazilites”—i.e., Seceders—who denied the eternity of the Koran. They protested their respect for Islam’s holy book, but they argued that where it or the Hadith contradicted reason, the Koran or the traditions must be interpreted allegorically; and they gave the name kalam or logic to this effort to reconcile reason and faith. It seemed to them absurd to take literally those Koranic passages that ascribed hands and feet, anger and hatred, to Allah; such poetic anthropomorphism, however adapted to the moral and political ends of Mohammed at the time, could hardly be accepted by the educated intellect. The human mind could never know what was the real nature or attributes of God; it could only agree with faith in affirming a spiritual power as the foundation of all reality. Furthermore, to the Mutazilites, it seemed fatal to human morality and enterprise to believe, as orthodoxy did, in the complete predestination of all events by God, and the arbitrary election, from all eternity, of the saved and the damned.
In a hundred variations of these themes, Mutazilite doctrines spread rapidly under the rule of al-Mansur, Harun al-Rashid, and al-Mamun. At first in the privacy of scholars and infidels, then in the soirees of the caliphs, finally in the lecture circles of colleges and mosques, the new rationalism won a voice, even, here and there, ascendancy. Al-Mamun was fascinated by this fledgling flight of reason, defended it, and ended by proclaiming the Mutazilite views as the official faith of the realm. Mingling old habits of Oriental monarchy with the latest ideas of Hellenizing Moslems, al-Mamun in 832 issued a decree requiring all Moslems to admit that the Koran had been created in time; a later decree ruled that no one could be a witness in law, or a judge, unless he declared his acceptance of the new dogma; further decrees extended this obligatory acceptance to the doctrines of free will, and the impossibility of the soul ever seeing God with a physical eye; at last, refusal to take these tests and oaths was made a capital crime. Al-Mamun died in 833, but his successors al-Mutassim and al-Wathiq continued his campaign. The theologian Ibn Hanbal denounced this inquisition; summoned to take the tests, he answered all questions by quoting the Koran in favor of the orthodox view. He was scourged to unconsciousness and cast into jail; but his sufferings made him, in the eyes of the people, a martyr and a saint, and prepared for the reaction that overwhelmed Moslem philosophy.
Meanwhile that philosophy had produced its first major figure. Abu Yusuf Yaqub ibn Ishaq al-Kindi was born in Kufa about 803, son of the governor of the city; he studied there and at Baghdad, and won a high reputation at the courts of al-Mamun and al-Mutassim as translator, scientist, and philosopher. Like so many thinkers in that confident heyday of the Moslem mind, he was an omnivorous polymath, studying everything, writing 265 treatises about everything—arithmetic, geometry, astronomy, meteorology, geography, physics, politics, music, medicine, philosophy…. He agreed with Plato that no one could be a philosopher without being first a mathematician, and he struggled to reduce health, medicine, and music to mathematical relations. He studied the tides, sought the laws that determine the speed of a falling body, and investigated the phenomena of light in a book on Optics which influenced Roger Bacon. He shocked the Moslem world by writing an Apology for Christianity.54 He and an aide translated the apocryphalTheology of Aristotle; he was deeply impressed by this forgery, and rejoiced in the thought that it reconciled Aristotle with Plato—by turning both of them into Neoplatonists. Al-Kindi’s philosophy was Neoplatonism restated: spirit has three grades—God, the creative World Soul or Logos, and its emanation, the soul of man; if a man trains his soul to right knowledge he can achieve freedom and deathlessness.55 Apparently al-Kindi made heroic efforts to be orthodox; yet he took from Aristotle56 the distinction between the active intellect, which is divine, and the passive intellect of man, which is merely the capacity for thought; Avicenna would transmit this distinction to Averroës, who would set the world by the ears with it as an argument against personal immortality. Al-Kindi associated with Mutazilites; when the reaction came his library was confiscated, and his deathlessness hung by a thread. He survived the storm, recovered his liberty, and lived till 873.
In a society where government, law, and morality are bound up with a religious creed, any attack upon that creed is viewed as menacing the foundations of social order itself. All the forces that had been beaten down by the Arab conquest—Greek philosophy, Gnostic Christianity, Persian nationalism, Mazdakite communism—were rampantly resurgent; the Koran was questioned and ridiculed; a Persian poet was decapitated for proclaiming the superiority of his verses to the Koran (784);57 the whole structure of Islam, resting on the Koran, seemed ready to collapse. In this crisis three factors made orthodoxy victorious: a conservative caliph, the rise of the Turkish guard, and the natural loyalty of the people to their inherited beliefs. Al-Mutawakkil, coming to the throne in 847, based his support upon the populace and the Turks; and the Turks, new converts to Mohammedanism, hostile to the Persians, and strangers to Greek thought, gave themselves with a whole heart to a policy of saving the faith by the sword. Al-Mutawakkil annulled and reversed the illiberal liberalism of al-Mamun; Mutazilites and other heretics were expelled from governmental employ and educational positions; any expression of heterodox ideas in literature or philosophy was forbidden; the eternity of the Koran was re-established by law. The Shia sect was proscribed, and the shrine of Husein at Kerbela was destroyed (851). The edict allegedly issued by Omar I against Christians, and extended to the Jews by Harun (807) and soon again ignored, was reissued by al-Mutawakkil (850); Jews and Christians were ordered to wear a distinctive color of dress, put colored patches on the garments of their slaves, ride only on mules and asses, and affix wooden devils to their doors. New churches and synagogues were to be pulled down, and no public elevation of the cross was to be allowed in Christian ceremonies. No Christian or Jew was to receive education in Moslem schools.58
In the next generation the reaction took a milder form. Some orthodox theologians, bravely accepting the gage of logic, proposed to prove by reason the truth of the traditional faith. These mutakallimun (i.e., logicians) were the Scholastics of Islam; they undertook that same reconciliation of religious dogma with Greek philosophy which Maimonides in the twelfth century would attempt for Judaism, and Thomas Aquinas in the thirteenth for Christianity. Abul-Hasan al-Ashari (873–935) of Basra, after teaching Mutazilite doctrines for a decade, turned against them in his fortieth year, attacked them with the Mutazilite weapon of logic, and poured forth a stream of conservative polemics that shared powerfully in the victory of the old creed. He accepted the predestinarianism of Mohammed without flinching: God has predetermined every act and event, and is their primary cause; He is above all law and morals; He “rules as a sovereign over His creatures, doing what He wills; if He were to send them all to hell there would be no wrong.”59 Not all the orthodox relished this submission of the faith to intellectual debate; many proclaimed the formula Bila kayf—“Believe without asking how.”60 The theologians for the most part ceased to discuss basic issues, but lost themselves in the scholastic minutiae of a doctrine whose fundamentals they accepted as axioms.
The ferment of philosophy subsided at Baghdad, only to emerge at minor courts. Sayfu’l-Dawla provided a house at Aleppo for Muhammad Abu Nasr al-Farabi, the first Turk to make a name in philosophy. Born at Farab in Turkestan, he studied logic under Christian teachers at Baghdad and Harran, read Aristotle’s Physics forty times and the De Anima 200 times, was denounced as a heretic at Baghdad, adopted the doctrine and dress of a Sufi, and lived like the swallows of the air. “He was the most indifferent of men to the things of this world,” says Ibn Khallikan; “he never gave himself the least trouble to acquire a livelihood or possess a habitation.”61 Sayfu’l-Dawla asked him how much he needed for his maintenance; al-Farabi thought that four dirhems ($2.00) a day would suffice; the prince settled this allowance on him for life.
Thirty-nine works by al-Farabi survive, many of them commentaries on Aristotle. His Ihsa al-ulum, or Encyclopedia of Science, summarized the knowledge of his time in philology, logic, mathematics, physics, chemistry, economics, and politics. He answered with a straightforward negative the question that would soon agitate the Scholastic philosophers of Christendom: Does the universal (the genus, the species, or the quality) exist apart from the specific individual? Deceived like the rest by the Theology of Aristotle, he transformed the hard-headed Stagirite into a mystic, and lived long enough to subside into orthodox belief. Having in his youth professed a theoretical agnosticism,62 he progressed sufficiently in later life to give a detailed description of the deity.63He took over Aristotle’s proofs of God’s existence very much as Aquinas would do three centuries later: a chain of contingent events requires for its intelligibility an ultimate necessary being; a chain of causes requires a First Cause; a series of motions requires a Prime Mover unmoved; multiplicity requires unity. The ultimate goal of philosophy, never quite attainable, is knowledge of the First Cause; the best approach to such knowledge is purity of soul. Like Aristotle, al-Farabi carefully managed to make himself unintelligible on immortality. He died at Damascus in 950.
One work alone, among his remains, strikes us with its original force: Al-Medina al-Fadila—The Ideal City. It opens with a description of the law of nature as one of perpetual struggle of each organism against all the rest—Hobbes’ bellum omnium contra omnes;every living thing, in the last analysis, sees in all other living things a means to its ends. Some cynics argue from this, says al-Farabi, that in this inescapable competition the wise man is he who best bends others to his will, and most fully achieves his own desires. How did human society emerge from this jungle law? If we may trust al-Farabi’s account, there were both Rousseauians and Nietzscheans among the Moslems who took up this question: some thought that society had begun in an agreement, among individuals, that their survival required the acceptance of certain restraints through custom or law; others laughed this “social contract” out of history, and insisted that society, or the state, had begun as the conquest and regimentation of the weak by the strong. States themselves,said these Nietzscheans, are organs of competition; it is natural that states should struggle with one another for ascendancy, security, power, and wealth; war is natural and inevitable; and in that final arbitrament, as in the law of nature, the only right is might. Al-Farabi counters this view with an appeal to his fellow men to build a society not upon envy, power, and strife, but upon reason, devotion, and love.64 He ends safely by recommending a monarchy based upon strong religious belief.65
A pupil of a pupil of al-Farabi established at Baghdad, about 970, an association of savants—known to us only from its founder’s place name as the Sidjistani Society—for the discussion of philosophical problems. No questions were asked as to the national origin or religious affiliation of any member. The group seems to have drowned itself in logic and epistemology, but its existence indicates that intellectual appetite survived in the capital. Of greater moment or result was a similar but secret fraternity of scientists and philosophers organized at Basra about 983. These “Brethren of Sincerity” or Purity (Ikhwan al-Safa) were alarmed by the weakening of the caliphate, the poverty of the people, and the corruption of morals; they aspired to a moral, spiritual, and political renovation of Islam; and thought that this renewal might be founded upon a blend of Greek philosophy, Christian ethics, Sufi mysticism, Shia politics, and Moslem law. They conceived friendship as a collaboration of abilities and virtues, each party bringing to the union a quality of which the others had lack and need; truth, they thought, comes more readily from a meeting of minds than from individual thought. So they privately met and discussed, with fine freedom, catholicity, and courtesy, all the basic problems of life, and finally issued fifty-one tracts as their considered and co-operative system and epitome of science, religion, and philosophy. A Spanish Moslem, traveling in the Near East about the year 1000, took a fancy to these treatises, collected them, and preserved them.
In these 1134 pages we find scientific explanations of tides, earthquakes, eclipses, sound waves, and many other natural phenomena; a full acceptance of astrology and alchemy; and occasional dallying with magic and numerology. The theology, as in nearly all Moslem thinkers, is Gnostic and Neoplatonic: from the First Cause or God emanates the Active Intelligence (Logos, Reason), from which proceeds the world of bodies and souls. All material things are formed by, and act through, soul. Every soul is restless until it rejoins the Active Intelligence or World Soul. This union demands absolute purity in the soul; ethics is the art of attaining this purity; science, philosophy, and religion are means to such purification. In seeking purity we must try to model ourselves upon the intellectual devotion of Socrates, the universal charity of Christ, and the modest nobility of Ali. When the mind has been emancipated by knowledge it should feel free to reinterpret through allegory, and thereby reconcile with philosophy, “the crude expressions of the Koran, which were adapted to the understanding of an uncivilized desert people”66—a sharp Persian retort to Arab pride. All in all, these fifty-one tracts constitute the fullest and most consistent expression that we possess of Moslem thought in the Abbasid age. The orthodox leaders in Baghdad burned them as heresy in 1150, but they continued to circulate, and exercised a pervasive influence upon Moslem and Jewish philosophy—upon al-Ghazali and Averroës, ibn Gabirol and Judah Halevi,67 the philosophical poet al-Ma‘arri, and perhaps upon the man who in his brief life rivaled the scope and depth, and surpassed the rationality, of this co-operative synthesis.
For Ibn Sina—Avicenna—was not content to be a scientist and a world-renowned authority on medicine; doubtless he knew that a scientist completes himself only through philosophy. He tells us that he read Aristotle’s Metaphysics forty times without understanding it, and that when al-Farabi’s commentary enabled him to comprehend the book he was so happy and grateful that he rushed into the street and scattered alms.68 Aristotle remained to the end his ideal in philosophy; already in the Qanun he used of him that phrase, “the philosopher,” which was to become in the Latin world a synonym for Aristotle. He detailed his own philosophy in the Kitab al-Shifa, and then summarized it in the Najat. He had a flair for logic, and insisted on precise definitions. He gave the classic medieval answer to the question whether universals or general ideas (man, virtue, redness) exist apart from individual things: they exist (1) ante res, “before the things,” in the mind of God as Platonic exemplars according to which the things are made; (2) in rebus, “in the things” in which they appear or are exemplified; and (3) post res, “after the things,” as abstract(ed) ideas in the human mind; but universals do not exist in the natural world apart from individual things. Abélard and Aquinas would, after a century of turmoil, give the same reply.
Indeed, Avicenna’s metaphysics is almost a summary of what, two centuries after him, the Latin thinkers would syncretize as the Scholastic philosophy. He begins with a laborious restatement of Aristotle and al-Farabi on matter and form, the four causes, the contingent and the necessary, the many and the one, and frets over the puzzle of how the contingent and changeable many—the multiplicity of mortal things—could ever have flowed from the necessary and changeless One. Like Plotinus he thinks to solve the problem by postulating an intermediate Active Intelligence, distributed through the celestial, material, and human world as souls. Finding some difficulty in reconciling God’s passage from noncreation to creation with the divine immutability, he proposes to believe, with Aristotle, in the eternity of the material world; but knowing that this will offend the mutakallimun, he offers them a compromise by a favorite Scholastic distinction: God is prior to the world not in time but logically, i.e., in rank and essence and cause: the existence of the world depends at every moment upon the existence of its sustaining force, which is God. Avicenna concedes that all entities but God are contingent—i.e., their existence is not inevitable or indispensable. Since such contingent things require a cause for their existence, they cannot be explained except by reverting, in the chain of causes, to a necessary being—one whose essence or meaning involves existence, a being whose existence must be presupposed in order to explain any other existence. God is the only being that exists by its own essence; it is essential that He exist, for without such a First Cause nothing that is could have begun to be. Since all matter is contingent—i.e., its essence does not involve existence—God cannot be material. For like reasons He must be simple and one. Since there is intelligence in created beings, there must be intelligence in their creator. The Supreme Intelligence sees all things—past, present, and future—not in time or sequence but at once; their occurrence is the temporal result of His timeless thought. But God does not directly cause each action or event; things develop by an internal teleology—they have their purposes and destinies written in themselves. Therefore God is not responsible for evil; evil is the price we pay for freedom of will; and the evil of the part may be the good of the whole.69
The existence of the soul is attested by our most immediate internal perception. The soul is spiritual for the same reason: we simply perceive it to be so; our ideas are clearly distinct from our organs. The soul is the principle of self-movement and growth in a body; in this sense even the celestial spheres have souls; “the whole cosmos is the manifestation of a universal principle of life.”70 By itself a body can cause nothing; the cause of its every motion is its inherent soul. Each soul or intelligence possesses a measure of freedom and creative power akin to that of the First Cause, for it is an emanation of that Cause. After death the pure soul returns to union with the World Soul; and in this union lies the blessedness of the good.71
Avicenna achieved as well as any man the ever-sought reconciliation between the faith of the people and the reasoning of the philosophers. He did not wish, like Lucretius, to destroy religion for the sake of philosophy, nor, like al-Ghazali in the ensuing century, to destroy philosophy for the sake of religion. He treats all questions with reason only, quite independently of the Koran, and gives a naturalistic analysis of inspiration;72 but he affirms the people’s need of prophets who expound to them the laws of morality in forms and parables popularly intelligible and effective; in this sense, as laying or preserving the foundations of social and moral development, the prophet is God’s messenger.73 So Mohammed preached the resurrection of the body, and sometimes described heaven in material terms; the philosopher will doubt the immortality of the body, but he will recognize that if Mohammed had taught a purely spiritual heaven the people would not have listened to him, and would not have united into a disciplined and powerful nation. Those who can worship God in spiritual love, entertaining neither hope nor fear, are the highest of mankind; but they will reveal this attitude only to their maturest students, not to the multitude.74
Avicenna’s Shifa and Qanun mark the apex of medieval thought, and constitute one of the major syntheses in the history of the mind. Much of it followed the lead of Aristotle and al-Farabi, as much of Aristotle followed Plato; only lunatics can be completely original. Avicenna occasionally talks what seems to our fallible judgment to be nonsense; but that is also true of Plato and Aristotle; there is nothing so foolish but it may be found in the pages of the philosophers. Avicenna lacked the honest uncertainty, critical spirit, and ever open mind of al-Biruni, and made many more mistakes; synthesis must pay that price as long as life is brief. He surpassed his rivals in the clarity and vivacity of his style, in the ability to relieve and illuminate abstract thought with illustrative anecdote and pardonable poetry, and in the unparalleled scope of his scientific and philosophical range. His influence was immense: it reached out to Spain to mold Averroës and Maimonides, and into Latin Christendom to help the great Scholastics; it is astonishing how much of Albertus Magnus and Thomas Aquinas goes back to Avicenna. Roger Bacon called him “the chief authority in philosophy after Aristotle”;75 and Aquinas was not merely practicing his customary courtesy in speaking of him with as much respect as of Plato.76
Arabic philosophy in the East almost died with Avicenna. Soon after his culminating effort the orthodox emphasis of the Seljuqs, the frightened fideism of the theologians, the victorious mysticism of al-Ghazali put a cloture on speculative thought. It is a pity that we know these three centuries (750–1050) of Arabic efflorescence so imperfectly. Thousands of Arabic manuscripts in science, literature, and philosophy lie hidden in the libraries of the Moslem world: in Constantinople alone there are thirty mosque libraries whose wealth has been merely scratched; in Cairo, Damascus, Mosul, Baghdad, Delhi are great collections not even catalogued; an immense library in the Escorial near Madrid has hardly completed the listing of its Islamic manuscripts in science, literature, jurisprudence, and philosophy.77 What we know of Moslem thought in those centuries is a fragment of what survives, what survives is a fragment of what was produced; what appears in these pages is a morsel of a fraction of a fragment. When scholarship has surveyed more thoroughly this half-forgotten legacy, we shall probably rank the tenth century in Eastern Islam as one of the golden ages in the history of the mind.