Sabtu, 21 Agustus 2010

Ibn Ishaq Al-Kindi (Alkindus)


al-Kindī (الكندي)
Alkindus

Portrait of Al-Kindi

Abū Yūsuf Yaʻqūb ibn Isḥāq al-Kindī (Arabic: أبو يوسف يعقوب إبن إسحاق الكندي‎) (c. 801–873 CE), also known to the West by the Latinized version of his name Alkindus, was an Arab Iraqi polymath: an Islamic philosopher, scientist, astrologer, astronomer, cosmologist, chemist, logician, mathematician, musician, physician, physicist, psychologist, and meteorologist.[verification needed] Al-Kindi was the first of the Muslim Peripatetic philosophers, and is known for his efforts to introduce Greek and Hellenistic philosophy to the Arab world, and as a pioneer in chemistry, medicine, music theory, physics, psychology,the philosophy of science, and is also known for being one of the fathers of cryptography.

Al-Kindi was a descendant of the Kinda tribe which is a well known Arabic tribe native of Najd (present day Saudi Arabia). He was born and educated in Kufa, before pursuing further studies in Baghdad. Al-Kindi became a prominent figure in the House of Wisdom, and a number of Abbasid Caliphs appointed him to oversee the translation of Greek scientific and philosophical texts into the Arabic language. This contact with "the philosophy of the ancients" (as Greek and Hellenistic philosophy was often referred to by Muslim scholars) had a profound effect on his intellectual development, and led him to write original treatises on subjects ranging from Islamic ethics and metaphysics to mathematics and pharmacology.

In mathematics, al-Kindi played an important role in introducing Arabic numerals to the Islamic and Christian world. He was a pioneer in cryptanalysis and cryptology, and devised new methods of breaking ciphers, including the frequency analysis method. Using his mathematical and medical expertise, he developed a scale to allow doctors to quantify the potency of their medication. He also experimented with music therapy.[verification needed]

The central theme underpinning al-Kindi's philosophical writings is the compatibility between philosophy and other orthodox Islamic sciences, particularly theology. Many of his works deal with subjects that concerned theology, including the nature of God, the soul, and prophetic knowledge. However, despite the important role he played in making philosophy accessible to Muslim intellectuals, his own philosophical output was largely overshadowed by that of al-Farabi and very few of his texts are available for modern scholars to examine. However, he is still considered one of the greatest philosophers of Arab descent, and for this reason is known simply as "The Arab Philosopher".

Life

Al-Kindi was born in Kufa, Iraq to an aristocratic Kindah, the story of Al-Kindi's family moving from Yemen has not been proven. His full name was, in Abū-Yūsuf Ya‘qūb ibn Isḥāq ibn as-Ṣabbāḥ ibn ‘Omrān ibn Isma‘īl al-Kindī; (in Arabic: أبو يوسف يعقوب ابن اسحاق ابن الصّبّاح ابن عمران ابن اسماعيل الكندي‎). His father was the governor of Kufa, and al-Kindi received his preliminary education there. He later completed his studies in Baghdad, where he was patronized by the Abbasid Caliphs al-Ma'mun and al-Mu'tasim. Because of his learning and aptitude for study, al-Ma'mun appointed him to House of Wisdom in Baghdad, a recently established centre for the translation of philosophical and scientific texts. He was well known for his beautiful calligraphy, and at one point was employed as a calligrapher by al-Mutawakkil.

When al-Ma'mun died, his brother, al-Mu'tasim became Caliph. Al-Kindi's position was enhanced under al-Mu'tasim, who appointed him as a tutor to his son. But on the accession of al-Wathiq, and especially of al-Mutawakkil, al-Kindi's star waned. There are various theories why this happened: some attribute al-Kindi's downfall to scholarly rivalries at the House of Wisdom; others refer to al-Mutawakkil’s often violent persecution of unorthodox Muslims (as well as of non-Muslims); at one point al-Kindi was beaten and his library temporarily confiscated. Al-Kindi died in Baghdad in 873, during the reign of Al-Mu'tamid, "a lonely man".

After his death, al-Kindi's philosophical works quickly fell into obscurity and many of them were lost even to later Islamic scholars and historians. This may have occurred for a number of reasons. Aside from the militant orthodoxy of al-Mutawakkil, the Mongols destroyed countless libraries during their invasion. However, the most probable cause was that his writings never found popularity among influential philosophers such as al-Farabi and Avicenna, who ultimately overshadowed him.

Accomplishments

Al-Kindi was a master of many different areas of thought. Although he would eventually be eclipsed by names such as al-Farabi and Avicenna, he was held to be one of the greatest Islamic philosophers of his time. The historian Ibn al-Nadim (d. 955), described him as:

The best man of his time, unique in his knowledge of all the ancient sciences. He is called the Philosopher of the Arabs. His books deal with different sciences, such as logic, philosophy, geometry, arithmetic, astronomy etc. We have connected him with the natural philosophers because of his prominence in Science.

The Italian Renaissance scholar Gerolamo Cardano (1501–1575) considered him one of the twelve greatest minds of the Middle Ages.[14] According to Ibn al-Nadim, al-Kindi wrote at least two hundred and sixty books, contributing heavily to geometry (thirty-two books), medicine and philosophy (twenty-two books each), logic (nine books), and physics (twelve books). His influence in the fields of physics, mathematics, medicine, philosophy and music were far-reaching and lasted for several centuries. Although most of his books have been lost over the centuries, a few have survived in the form of Latin translations by Gerard of Cremona, and others have been rediscovered in Arabic manuscripts; most importantly, twenty-four of his lost works were located in the mid-twentieth century in a Turkish library. The Theology of Aristotle, a paraphrase of parts of Plotinus' Six Enneads along with Porphyry's commentary, seems to have been edited by Al-Kindi.

Astrology, astronomy, and cosmology

In astrology and astronomy, al-Kindi followed Ptolemy's view of the solar system with the Earth at the centre of a series of concentric spheres, in which the known heavenly bodies (the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and the stars) are embedded. In one of his treatises on the subject, he says that these bodies are rational entities, whose circular motion is in obedience to and worship of God. Their role, al-Kindi believes, is to act as instruments for divine providence. He furnishes empirical evidence as proof for this assertion: different seasons are marked by particular arrangements of the planets and stars (most notably the sun), and (according to al-Kindi) the appearance and manner of people varies according to the arrangement of heavenly bodies situated above their homeland.

Al-Kindi discussed the process by which the heavenly bodies affect the material world. One theory he posits in his works is from Aristotle, who conceived that the movement of these bodies causes friction in the sub-lunar region, which stirs up the primary elements of earth, fire, air and water, and these combine to produce everything in the material world. An alternative view found in his treatise On Rays is that the planets exercise their influence in straight lines. In each of these, he presents two fundamentally different views of physical interaction; action by contact and action at a distance. This dichotomy is duplicated in his writings on optics.

In cosmology, al-Kindi maintained the traditional Aristotelian view of gravity according to which heavy bodies, such as the Earth, move downward toward the centre and light bodies, such as Fire, move upward away from the centre.

Chemistry and perfumery

As an advanced chemist, al-Kindi was the first to oppose the practice of alchemy; he debunked the myth that simple, base metals could be transformed into precious metals such as gold or silver. He wrote two treatises on the refutation of alchemy: Warning against the Deceptions of the Alchemists and Refutation of the Claim of Those Who Claim the Artificial Fabrication of Gold and Silver.

Building on the work of Jābir ibn Hayyān (Geber), the isolation of ethanol (alcohol) as a relatively pure compound was first achieved by al-Kindi. He was the first to unambiguously describe the production of pure distilled alcohol from the distillation of wine.[unreliable source?]

Al-Kindi invented a wide variety of scent and perfume products, and is considered the father of the perfume industry. He carried out extensive research and experiments in combining various plants and other sources to produce a variety of scent products. He elaborated a vast number of recipes for a wide range of perfumes, cosmetics and pharmaceuticals. His work in the laboratory is reported by a witness who said, "I received the following description, or recipe, from Abu Yusuf Ya'qub b. Ishaq al-Kindi, and I saw him making it and giving it an addition in my presence". The writer goes on in the same section to speak of the preparation of a perfume called ghaliya, which contained musk, amber and other ingredients, and reveals a long list of technical names of drugs and apparatus.[2][verification needed]

The Kitab Kimiya' al-'Itr (Book of the Chemistry of Perfume) written by al-Kindi contains recipes for fragrant oils, salves, aromatic waters, and substitutes or imitations of costly drugs. He also provided the earliest recipe for the production of camphor.[verification needed]

The first page of al-Kindi's manuscript On Deciphering Cryptographic Messages, containing the oldest known description of cryptanalysis by frequency analysis.

Al-Kindi is also noted for his experiments on Botanical and chemical work such as: A Treatise on the Artificial Production of Foodstuffs without their Elements, which describes the same kind of experiment with a different range of material. The work, was for theoretical purposes, and the experiments might have been made for the relief of famine.

Cryptography and mathematics

Al-Kindi was a pioneer in cryptography, especially cryptanalysis. He gave the first known recorded explanation of cryptanalysis in A Manuscript on Deciphering Cryptographic Messages. In particular, he is credited with developing the frequency analysis method whereby variations in the frequency of the occurrence of letters could be analyzed and exploited to break ciphers (i.e. cryptanalysis by frequency analysis). This was detailed in a text recently rediscovered in the Ottoman archives in Istanbul, A Manuscript on Deciphering Cryptographic Messages, which also covers methods of cryptanalysis, encipherments, cryptanalysis of certain encipherments, and statistical analysis of letters and letter combinations in Arabic. Al-Kindi also had knowledge of polyalphabetic ciphers centuries before Leon Battista Alberti. Al-Kindi's book also introduced the classification of ciphers, developed Arabic phonetics and syntax, and described the use of several statistical techniques for cryptoanalysis. This book apparently antedates other cryptology references by several centuries, and it also predates writings on probability and statistics by Pascal and Fermat by nearly eight centuries.

Al-Kindi authored works on a number of other important mathematical subjects, including arithmetic, geometry, the Indian numbers, the harmony of numbers, lines and multiplication with numbers, relative quantities, measuring proportion and time, and numerical procedures and cancellation. He also wrote four volumes, On the Use of the Indian Numerals (Ketab fi Isti'mal al-'Adad al-Hindi) which contributed greatly to diffusion of the Indian system of numeration in the Middle East and the West. In geometry, among other works, he wrote on the theory of parallels. Also related to geometry were two works on optics. One of the ways in which he made use of mathematics as a philosopher was to attempt to disprove the eternity of the world by demonstrating that actual infinity is a mathematical and logical absurdity.

Environmentalism and meteorology

The earliest known work concerned with environmentalism and pollution was an Arabic medical treatise written by al-Kindi. His writings, along with the works of his successors (Qusta ibn Luqa, Muhammad ibn Zakarīya Rāzi, 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), covered a number of subjects related to pollution such as air contamination, water contamination, soil contamination, solid waste mishandling, and environmental assessments of certain localities.

Al-Kindi wrote a treatise on meteorology entitled Risala fi l-Illa al-Failali l-Madd wa l-Fazr (Treatise on the Efficient Cause of the Flow and Ebb), in which he presents an argument on tides which "depends on the changes which take place in bodies owing to the rise and fall of temperature."[verification needed] He describes the following clear and precise laboratory experiment in order to prove that the air turns into water:

One can also observe by the senses... how in consequence of extreme cold air changes into water. To do this, one takes a glass bottle, fills it completely with snow, and closes its end carefully. Then one determines its weight by weighing. One places it in a container... which has previously been weighed. On the surface of the bottle the air changes into water, and appears upon it like the drops on large porous pitchers, so that a considerable amount of water gradually collects inside the container. One then weighs the bottle, the water and the container, and finds their weight greater than previously, which proves the change. [...] Some foolish persons are of opinion that the snow exudes through the glass. This is impossible. There is no process by which water or snow can be made to pass through glass.

Medicine

There are more than thirty treatises attributed to al-Kindi in the field of medicine, in which he was partly influenced by the ideas of Galen, and partly by his own personal experience and other Muslim physicians in his time.

Al-Kindi's most important work in this field is probably De Gradibus, in which he demonstrates the application of mathematics and quantification to medicine, particularly in the field of pharmacology. For example, he developed a mathematical scale to quantify the strength of a drug and a system, based on the phases of the Moon, that would allow a doctor to determine in advance the most critical days of a patient's illness.

In his Treatise on Diseases Caused by Phlegm, he provided the first scientific explanation and treatment for epilepsy:

When the phlegm melts and changes to a bad irritant quality, it goes forth and ascends to the brain from a certain direction, then it sinks down through the principal veins towards the heart, and by its irritant quality it deranges the place of sense, thought and recollection in the brain. It passes through the veins towards the heart, and if the natural heat whose source is the heart is strong enough to dissolve it, it does so, and what happens as a consequence is epilepsy (sar). For the parts of the brain which we have mentioned, becoming injured, are overcome and cease to function. The disturbance which we see in the (patient’s) body is owing to the conflict of the natural (heat) with the affection. When it prevails over it, it attacks and dissolves it. This is the meaning of the foam which is seen at the (patient’s) mouth. When this occurs, his recovery is near.

In his Aqrabadhin (Medical Formulary), he describes many pharmaceutical preparations, including simple drugs derived mostly from botanical sources as well as animal and mineral sources.

The Kitab Kimiya' al-'Itr (Book of the Chemistry of Perfume) written by al-Kindi contains recipes for salves and substitutes or imitations of costly drugs.

Music theory

Al-Kindi was the first great theoretician of music in the Arab-Islamic world. He proposed adding a fifth string to the 'ud and discussed the cosmological connotations of music. He surpassed the achievement of the Greek musicians in using the alphabetical annotation for one eighth. He published fifteen treatises on music theory, but only five have survived. In one of his treaties the word musiqia was used for the first time in Arabic, which today means music in Arabic, Persian, Turkish, English and several other languages in the Islamic world.

Philosophy and logic

His greatest contribution to the development of early Islamic philosophy was his efforts to make Greek and Hellenistic thought both accessible and acceptable to a Muslim audience. Al-Kindi carried out this mission from the House of Wisdom, an institute of translation and learning patronized by the Abbasid Caliphs, in Baghdad. As well as translating many important texts, much of what was to become standard Arabic philosophical vocabulary originated with al-Kindi; indeed, if it had not been for him, the work of philosophers like Al-Farabi, Avicenna, and al-Ghazali might not have been possible.[33]

In his writings, one of al-Kindi's central concerns was to demonstrate the compatibility between philosophy and natural theology on the one hand, and revealed or speculative theology on the other (though in fact he rejected speculative theology). Despite this, he did make clear that he believed revelation was a superior source of knowledge to reason because it guaranteed matters of faith that reason could not uncover. While his philosophical approach was not always original, and was even considered clumsy by later thinkers, he successfully incorporated Aristotelian and neo-Platonist thought into an Islamic philosophical framework. This was an important factor in the introduction and popularization of Greek philosophy in the Muslim intellectual world.[34]

Most early writers on logic in Islamic philosophy during the 8th and 9th centuries produced commentaries on Aristotelian logic. The first original Arabic writings on logic were produced by al-Kindi, who produced a summary on earlier logic up to his time.[35]

[edit] Philosophy of science

Al-Kindi made important contributions to the philosophy of science and the development of scientific methodology. Like his Arab predecessor Jābir ibn Hayyān, al-Kindi placed a strong emphasis on experimentation, and in addition, he introduced a new emphasis on quantification. He also wrote the following on his view of scientific knowledge:[22]

We must not hesitate to recognize the truth and to accept it no matter what is its origin, no matter if it comes to us from the ancients or from foreign people... My purpose is first to write down all that the ancients have left us on a given topic and then, using the Arabic tongue and taking into account the customs of our time and our capacities, to complete what they have not fully expressed.

Though al-Kindi held ancient authorities (such as Aristotle) in high regard, he often criticized them for making claims regarding natural philosophy without providing any empirical proof, nor any empirical evidence or scientific demonstration. In many instances, al-Kindi used experiments and quantitative methods to verify many of his own theories, as he recognized the importance of direct observation and empiricism as a source of scientific knowledge. He also often invented specific laboratory apparatus in order to carry out his experiments.[2]

[edit] Physics

Two major theories of optics appear in the writings of al-Kindi; Aristotelian and Euclidian. Aristotle had believed that in order for the eye to perceive an object, both the eye and the object must be in contact with a transparent medium (such as air) that is filled with light. When these criteria are met, the "sensible form" of the object is transmitted through the medium to the eye. On the other hand, Euclid proposed that vision depends upon mathematically describable "rays" that reach out in straight lines from the eye to touch the object of vision. As with his theories on Astrology, the dichotomy of contact and distance is present in al-Kindi's writings on this subject as well.

The factor which al-Kindi relied upon to determine which of these theories was most correct was how adequately each one explained the experience of seeing. For example, Aristotle's theory was unable to account for why the angle at which an individual sees an object affects his perception of it. For example, why a circle viewed from the side will appear as a line. According to Aristotle, the complete sensible form of a circle should be transmitted to the eye and it should appear as a circle. On the other hand, Euclidian optics provided a geometric model that was able to account for this, as well as the length of shadows and reflections in mirrors, because Euclid believed that the visual "rays" could only travel in straight lines (something which is commonly accepted in modern science). For this reason, al-Kindi considered the latter preponderant.[36]

In his Kitab al-Shu'a'at (Book of the Rays), al-Kindi wrote the following criticism on Anthemius of Tralles for reporting how "ships were set aflame by burning mirrors during a naval battle" without empirical evidence:[2][verification needed]

Anthemius should not have accepted information without proof... He tells how to construct a mirror from which twenty four rays are reflected on a single point, without showing how to establish where the rays unite at a given distance from the middle of the mirror's surface. We, on the other hand, have described this with as much evidence as our ability permits, furnishing what was missing, for he has not mentioned a definite distance.

Al-Kindi also described a camera obscura. He demonstrated that "light from the right side of the flame will pass through the aperture and end up on the left side of the screen, while light from the left side of the flame will pass through the aperture and end up on the right side of the screen."[verification needed]

Psychology

As an Islamic psychologist, al-Kindi was a pioneer in experimental psychology. He was the first to use the method of experiment in psychology, which led to his discovery that sensation is proportionate to the stimulus. He was also the earliest to realize the therapeutic value of music and attempted to cure a quadriplegic boy using music therapy.

He also dealt with psychology in several other treatises: On Sleep and Dreams (a treatise on dream interpretation), First Philosophy, and Eradication of Sorrow. In the latter, he described sorrow as "a spiritual (Nafsani) grief caused by loss of loved ones or personal belongings, or by failure in obtaining what one lusts after" and then added: "If causes of pain are discernible, the cures can be found." He recommended that "if we do not tolerate losing or dislike being deprived of what is dear to us, then we should seek after riches in the world of the intellect. In it we should treasure our precious and cherished gains where they can never be dispossessed...for that which is owned by our senses could easily be taken away from us." He also stated that "sorrow is not within us we bring it upon ourselves." He developed cognitive methods to combat depression and discussed the intellectual operations of human beings.

Philosophical thought

Influences

While Muslim intellectuals were already acquainted with Greek philosophy (especially logic), al-Kindi is credited with being the first real Muslim philosopher. His own thought was largely influenced by the Neo-Platonic philosophy of Plotinus, although he does appear to have borrowed ideas from other Hellenistic schools as well. He makes many references to Aristotle in his writings, but these are often unwittingly re-interpreted in a Neo-Platonic framework. This trend is most obvious in areas such as metaphysics and the nature of God as a causal entity. Earlier experts had suggested that he was influenced by the Mutazilite school of theology, because of the mutual concern both he and they demonstrated for maintaining the pure unity (tawhid) of God. However, such agreements are now considered incidental, as further study has shown that they disagreed on a number of equally important topics.

Metaphysics

According to al-Kindi, the goal of metaphysics is the knowledge of God. For this reason, he does make a clear distinction between philosophy and theology, because he believes they are both concerned with the same subject. Later philosophers, particularly al-Farabi and Avicenna, would strongly disagree with him on this issue, by saying that metaphysics is actually concerned with qua being, and as such, the nature of God is purely incidental.

Central to al-Kindi's understanding of metaphysics is God's absolute oneness, which he considers an attribute uniquely associated with God (and therefore not shared with anything else). By this he means that while we may think of any existent thing as being "one", it is in fact both "one" and many". For example, he says that while a body is one, it is also composed of many different parts. A person might say "I see an elephant", by which he means "I see one elephant", but the term 'elephant' refers to a species of animal that contains many. Therefore, only God is absolutely one, both in being and in concept, lacking any multiplicity whatsoever. This understanding entails a very rigorous negative theology because it implies that any description which can be predicated to anything else, cannot be said about God.

In addition to absolute oneness, al-Kindi also described God as the Creator. This means that He acts as both a final and efficient cause. Unlike later Muslim Neo-Platonic philosophers (who asserted that the universe existed as a result of God's existence "overflowing", which is a passive act), al-Kindi conceived of God as an active agent. In fact, of God as the agent, because all other intermediary agencies are contingent upon Him. The key idea here is that God "acts" through created intermediaries, which in turn "act" on one another - through a chain of cause and effect - to produce the desired result. In reality, these intermediary agents do not "act" at all, they are merely a conduit for God's own action. This is especially significant in the development of Islamic philosophy, as it portrayed the "first cause" and "unmoved mover" of Aristotelian philosophy as compatible with the concept of God according to Islamic revelation.

However, in contrast to ancient Greek philosophers such as Aristotle who believed that the universe had an infinite past with no beginning, Al-Kindi believed that the universe has a finite past with a beginning. This view was inspired by the creation doctrine shared by the three Abrahamic religions: Judaism, Christianity and Islam. The Christian philosopher, John Philoponus, presented the first such argument against the ancient Greek notion of an infinite past. Philoponus' logic was adopted by many, most notably; Al-Kindi, Saadia Gaon (Saadia ben Joseph) and Al-Ghazali (Algazel). They used two logical arguments against an infinite past, the first being the "argument from the impossibility of the existence of an actual infinite", which states:

"An actual infinite cannot exist."
"An infinite temporal regress of events is an actual infinite."
" An infinite temporal regress of events cannot exist."

The second argument, the "argument from the impossibility of completing an actual infinite by successive addition", states:

"An actual infinite cannot be completed by successive addition."
"The temporal series of past events has been completed by successive addition."
" The temporal series of past events cannot be an actual infinite."

Both arguments were adopted by later Christian philosophers and theologians, and the second argument in particular became more famous after it was adopted by Immanuel Kant in his thesis of the first antimony concerning time.

Epistemology

Ancient Greek philosophers such as Plato and Aristotle would become highly revered in the medieval Islamic world.

Al-Kindi theorized that there was a separate, incorporeal and universal intellect (known as the "First Intellect"). It was the first of God's creation and the intermediary through which all other things came into creation. Aside from its obvious metaphysical importance, it was also crucial to al-Kindi's epistemology, which was influenced by Platonic realism.

According to Plato, everything that exists in the material world corresponds to certain universal forms in the heavenly realm. These forms are really abstract concepts such as a species, quality or relation, which apply to all physical objects and beings. For example, a red apple has the quality of "redness" derived from the appropriate universal. However, al-Kindi says that human intellects are only potentially able to comprehend these. This potential is actualized by the First Intellect, which is perpetually thinking about all of the universals. He argues that the external agency of this intellect is necessary by saying that human beings cannot arrive at a universal concept merely through perception. In other words, an intellect cannot understand the species of a thing simply by examining one or more of its instances. According to him, this will only yield an inferior "sensible form", and not the universal form which we desire. The universal form can only be attained through contemplation and actualization by the First Intellect.

The analogy he provides to explain his theory is that of wood and fire. Wood, he argues, is potentially hot (just as a human is potentially thinking about a universal), and therefore requires something else which is already hot (such as fire) to actualize this. This means that for the human intellect to think about something, the First Intellect must already be thinking about it. Therefore he says that the First Intellect must always be thinking about everything. Once the human intellect comprehends a universal by this process, it becomes part of the individual's "acquired intellect" and can be thought about whenever he or she wishes.

The soul and the afterlife

Al-Kindi believed that the soul is a simple, immaterial substance, which is related to the material world only because of its faculties which operate through the physical body. To explain the nature of our worldly existence, he compares it to a ship which has, during the course of its ocean voyage, temporarily anchored itself at an island and allowed its passengers to disembark. The implicit warning is that those passengers who linger too long on the island may be left behind when the ship sets sail again. Here, al-Kindi displays a stoic concept, that we must not become attached to material things (represented by the island), as they will invariably be taken away from us (when the ship sets sail again). He then connects this by saying that our soul can be directed towards the pursuit of desire or the pursuit of intellect; the former will tie it to the body, so that when the body dies, it will also die, but the latter will free it from the body and allow it to survive "in the light of the Creator" in a realm of pure intelligence.

Al-Kindi further wrote:

Our residence in this phenomenal world is transitory; it is a journey towards the eternal one. The most miserable man, is he who prefers for himself the material above the spiritual, for the material, apart from its ephemeral nature, obstructs our passage to the spiritual world. Man should not `disregard any means to protect himself against all human vices, and he should seek to rise to the highest ends of human virtues..., that is, to the knowledge by means of which we protect ourselves against spiritual and bodily disease, and acquire the human virtues in whose very essence goodness is grounded.

The relationship between revelation and philosophy

In the view of al-Kindi, prophecy and philosophy were two different routes to arrive at the truth. He contrasts the two positions in four ways. Firstly, while a person must undergo a long period of training and study to become a philosopher, prophecy is bestowed upon someone by God. Secondly, the philosopher must arrive at the truth by his own devices (and with great difficulty), whereas the prophet has the truth revealed to him by God. Thirdly, the understanding of the prophet - being divinely revealed - is clearer and more comprehensive than that of the philosopher. Fourthly, the way in which the prophet is able to express this understanding to the ordinary people is superior. Therefore al-Kindi says the prophet is superior in two fields: the ease and certainty with which he receives the truth, and the way in which he presents it. However, the crucial implication is that the content of the prophet's and the philosopher's knowledge is the same. This, says Adamson, demonstrates how limited the superiority al-Kindi afforded to prophecy was.

In addition to this, al-Kindi adopted a naturalistic view of prophetic visions. He argued that, through the faculty of "imagination" as conceived of in Aristotelian philosophy, certain "pure" and well-prepared souls, were able to receive information about future events. Significantly, he does not attribute such visions or dreams to revelation from God, but instead explains that imagination enables human beings to receive the "form" of something without needing to perceive the physical entity to which it refers. Therefore, it would seem to imply that anyone who has purified themselves would be able to receive such visions. It is precisely this idea, amongst other naturalistic explanations of prophetic miracles, that al-Ghazali attacks in The Incoherence of the Philosophers.

Controversies

While al-Kindi appreciated the usefulness of philosophy in answering questions of a religious nature, there were many Islamic thinkers who were not as enthusiastic about the use of philosophy. However, it would be incorrect to assume that they opposed philosophy simply because it was a "foreign science". Oliver Leaman, an expert on Islamic philosophy, points out that the objections of notable theologians are rarely directed at philosophy itself, but rather at the conclusions the philosophers arrived at. Even al-Ghazali (famous for his critique of the philosophers, The Incoherence of the Philosophers), was himself an expert in philosophy and logic. Al-Ghazali's criticized the philosophers not for their methods, but for arriving at theologically erroneous conclusions. The three most serious of these, in his view, were believing in the co-eternity of the universe with God, denying the bodily resurrection, and asserting that God only has knowledge of abstract universals, not of particular things.

During his life, al-Kindi was fortunate enough to enjoy the patronage of the pro-Mutazilite Caliphs al-Ma'mun and al-Mu'tasim, which meant he could carry out his philosophical speculations with relative ease. This would change significantly towards the end of his life when al-Mutawakkil supported the traditionalists, and initiated persecution of various unorthodox schools of thought, including the philosophers. In his own time, al-Kindi would be criticized for extolling the "intellect" as being the most immanent creation in proximity to God, a standing commonly held to be the position only of the angels. He also engaged in disputations with the Mutazilites, whom he attacked for their belief in atoms. But the real role of al-Kindi in the conflict between philosophers and theologians would be to prepare the ground for debate. His works, says Deborah Black, contained all the seeds of future controversy that would be fully realized in al-Ghazali's book, Incoherence of the Philosophers.

From Wikipedia, the free encyclopedia.

Abul Waleed Muhammad Ibn Rushd (Averroes)


Abū 'l-Walīd Muḥammad ibn Aḥmad ibn Rushd (Arabic: أبو الوليد محمد بن احمد بن رشد‎), better known just as Ibn Rushd (Arabic: ابن رشد‎), and in European literature as Averroes (pronounced /əˈvɛroʊ.iːz/) (1126 – December 10, 1198), was an Andalusian Muslim polymath; a master of Islamic philosophy, Islamic theology, Maliki law and jurisprudence, logic, psychology, politics, Arabic music theory, and the sciences of medicine, astronomy, geography, mathematics, physics and celestial mechanics. He was born in Córdoba, Al Andalus, modern-day Spain, and died in Marrakesh, modern-day Morocco. His school of philosophy is known as Averroism. He has been described by some as the founding father of secular thought in Western Europe and "one of the spiritual fathers of Europe," although other scholars oppose such claims.

His name is also seen as Averroës, Averroès or Averrhoës, indicating that the "o" and the "e" form separate syllables. Averroes is a Latinate distortion of the actual Arab name Ibn Rushd.

According to Ernest Renan, he was also called as Ibin-Ros-din, Filius Rosadis, Ibn-Rusid, Ben-Raxid, Ibn-Ruschod, Den-Resched, Aben-Rassad, Aben-Rois, Aben-Rasd, Aben- Rust, Avenrosdy Avenryz, Adveroys, Benroist, Avenroyth, Averroysta, etc. "Averroès et l'Averroïsme : essai historique"

Biography

Ibn Rushd was born in Córdoba to a family with a long and well-respected tradition of legal and public service. His grandfather Abu Al-Walid Muhammad (d. 1126) was chief judge of Córdoba under the Almoravids. His father, Abu Al-Qasim Ahmad, held the same position until the Almoravids were replaced by the Almohads in 1146.

Ibn Rushd’s education followed a traditional path, beginning with studies in Hadith, linguistics, jurisprudence and scholastic theology. Throughout his life he wrote extensively on Philosophy and Religion, attributes of God, origin of the universe, Metaphysics and Psychology. It is generally believed that he was perhaps once tutored by Ibn Bajjah (Avempace). His medical education was directed under Abu Jafar ibn Harun of Trujillo in Seville.

Ibn Rushd began his career with the help of Ibn Tufail ("Aben Tofail" to the West), the author of Hayy ibn Yaqdhan and philosophic vizier of Almohad amir Abu Yaqub Yusuf. It was Ibn Tufail who introduced him to the court and to Ibn Zuhr ("Avenzoar" to the West), the great Muslim physician, who became Ibn Rushd's teacher and friend. Ibn Rushd's aptitude for medicine was noted by his contemporaries and can be seen in his major enduring work Kitab al-Kulyat fi al-Tibb (Generalities) the work was influenced by the Kitab al-Taisir fi al-Mudawat wa al-Tadbir (Particularities) of Ibn Zuhr. Ibn Rushd later reported how it was also Ibn Tufail that inspired him to write his famous commentaries on Aristotle:

Abu Bakr ibn Tufayl summoned me one day and told me that he had heard the Commander of the Faithful complaining about the disjointedness of Aristotle's mode of expression — or that of the translators — and the resultant obscurity of his intentions. He said that if someone took on these books who could summarize them and clarify their aims after first thoroughly understanding them himself, people would have an easier time comprehending them. “If you have the energy,” Ibn Tufayl told me, “you do it. I'm confident you can, because I know what a good mind and devoted character you have, and how dedicated you are to the art. You understand that only my great age, the cares of my office — and my commitment to another task that I think even more vital — keep me from doing it myself.”

Ibn Rushd was also a student of Ibn Bajjah ("Avempace" to the West), another famous Islamic philosopher who greatly influenced his own Averroist thought. However, while the thought of his mentors Ibn Tufail and Ibn Bajjah were mystic to an extent, the thought of Ibn Rushd was purely rationalist. Together, the three men are considered the greatest Andalusian philosophers.

In 1160, Ibn Rushd was made Qadi (judge) of Seville and he served in many court appointments in Seville, Cordoba, and Morocco during his career. At the end of the 12th century, following the Almohads conquest of Al-Andalus, his political career was ended. Ibn Rushd's strictly rationalist views which collided with the more orthodox views of Abu Yusuf Ya'qub al-Mansur who therefore eventually banished Averroes, though he had previously appointed him as his personal physician. Averroes was not reinstated until shortly before his death. He devoted the rest of his life (more than 30 years) to his philosophical writings, he died in the year 1198 AD.

Works

Ibn Rushd's works were spread over 20,000 pages covering a variety of different subjects, including early Islamic philosophy, logic in Islamic philosophy, Arabic medicine, Arabic mathematics, Arabic astronomy, Arabic grammar, Islamic theology, Sharia (Islamic law), and Fiqh (Islamic jurisprudence). In particular, his most important works dealt with Islamic philosophy, medicine and Fiqh. He wrote at least 67 original works, which included 28 works on philosophy, 20 on medicine, 8 on law, 5 on theology, and 4 on grammar, in addition to his commentaries on most of Aristotle's works and his commentary on Plato's The Republic.

He wrote commentaries on most of the surviving works of Aristotle. These were not based on primary sources (it is not known whether he knew Greek), but rather on Arabic translations. There were three levels of commentary: the Jami, the Talkhis and the Tafsir which are, respectively, a simplified overview, an intermediate commentary with more critical material, and an advanced study of Aristotelian thought in a Muslim context. The terms are taken from the names of different types of commentary on the Qur'an. It is not known whether he wrote commentaries of all three types on all the works: in most cases only one or two commentaries survive.

He did not have access to any text of Aristotle's Politics. As a substitute for this, he commented on Plato's The Republic, arguing that the ideal state there described was the same as the original constitution of the Arab Caliphate, as well as the Almohad state of Ibn Tumart.

Imaginary debate between Averroes and Porphyry. Monfredo de Monte Imperiali Liber de herbis, 14th century.

His most important original philosophical work was The Incoherence of the Incoherence (Tahafut al-tahafut), in which he defended Aristotelian philosophy against al-Ghazali's claims in The Incoherence of the Philosophers (Tahafut al-falasifa). Al-Ghazali argued that Aristotelianism, especially as presented in the writings of Avicenna, was self-contradictory and an affront to the teachings of Islam. Averroes' rebuttal was two-pronged: he contended both that al-Ghazali's arguments were mistaken and that, in any case, the system of Avicenna was a distortion of genuine Aristotelianism so that al-Ghazali was aiming at the wrong target. Other works were the Fasl al-Maqal, which argued for the legality of philosophical investigation under Islamic law, and the Kitab al-Kashf, which argued against the proofs of Islam advanced by the Ash'arite school and discussed what proofs, on the popular level, should be used instead.

Averroes is also a highly regarded legal scholar of the Maliki school. Perhaps his best-known work in this field is Bidāyat al-Mujtahid wa Nihāyat al-Muqtaṣid ( بداية المجتهد و نهاية المقتصد), a textbook of Maliki doctrine in a comparative framework.

In medicine, Averroes wrote a medical encyclopedia called Kulliyat ("Generalities", i.e. general medicine), known in its Latin translation as Colliget. He also made a compilation of the works of Galen (129-200) and wrote a commentary on The Law of Medicine (Qanun fi 't-tibb) of Avicenna (Ibn Sina) (980-1037).

Jacob Anatoli translated several of the works of Averroes from Arabic into Hebrew in the 13th century. Many of them were later translated from Hebrew into Latin by Jacob Mantino and Abraham de Balmes. Other works were translated directly from Arabic into Latin by Michael Scot. Many of his works in logic and metaphysics have been permanently lost, while others, including some of the longer Aristotelian commentaries, have only survived in Latin or Hebrew translation, not in the original Arabic. The fullest version of his works is in Latin, and forms part of the multi-volume Juntine edition of Aristotle published in Venice 1562-1574.

Contributions

Philosophy

Giovanni di Paolo's St. Thomas Aquinas Confounding Averroës.

According to Ibn Rushd, there is no conflict between religion and philosophy, rather that they are different ways of reaching the same truth. He believed in the eternity of the universe. He also held that the soul is divided into two parts, one individual and one divine; while the individual soul is not eternal, all humans at the basic level share one and the same divine soul. Ibn Rushd has two kinds of Knowledge of Truth. The first being his knowledge of truth of religion being based in faith and thus could not be tested, nor did it require training to understand. The second knowledge of truth is philosophy, which was reserved for an elite few who had the intellectual capacity to undertake this study.

The concept of "existence precedes essence", a key foundational concept of existentialism, can also be found in the works of Ibn Rushd, as a reaction to Ibn Sina's concept of "essence precedes existence". Ibn Rushd's most famous original philosophical work was The Incoherence of the Incoherence, a rebuttal to Al-Ghazali's The Incoherence of the Philosophers. In medieval Europe, his school of philosophy known as Averroism exerted a strong influence on Jewish philosophers such as Gersonides and Maimonides, and was opposed by Christian philosophers such as Thomas Aquinas.

Astronomy

At the age of 25, Ibn Rushd conducted astronomical observations near Marrakech, Morocco, during which he discovered a previously unobserved star.

In astronomical theory, Ibn Rushd rejected the eccentric deferents introduced by Ptolemy. He rejected the Ptolemaic model and instead argued for a strictly concentric model of the universe. He wrote the following criticism on the Ptolemaic model of planetary motion:

"To assert the existence of an eccentric sphere or an epicyclic sphere is contrary to nature. [...] The astronomy of our time offers no truth, but only agrees with the calculations and not with what exists."

Ibn Rushd also argued that the Moon is opaque and obscure, and has some parts which are thicker than others, with the thicker parts receiving more light from the Sun than the thinner parts of the Moon.He also gave one of the first descriptions on sunspots.

Celestial mechanics

In celestial mechanics, while discussing the celestial spheres, Averroes rejected John Philoponus' 'anti-Aristotelian' solution to his refutation of Aristotelian celestial dynamics, and instead restored Aristotle's law of motion by adopting the 'hidden variable' approach to resolving apparent refutations of parametric laws that posits a previously unaccounted variable and its value(s) for some parameter, thereby modifying the predicted value of the subject variable. For, he posited a non-gravitational, previously unaccounted, inherent resistance to motion, as hidden within the celestial spheres. This was a non-gravitational inherent resistance to motion of superlunary quintessential matter, whereby R > 0 even when there is neither any gravitational, nor any media resistance, to motion.

Hence, in refuting the prediction of Aristotelian celestial dynamics:

[ (i) v α F/R & (ii) F > 0 & (iii) R = 0 ] entail v is infinite

the alternative logic of Averroes' solution was to reject its third premise "R = 0" instead of rejecting its first premise as Philoponus had.

Thus Averroes most significantly revised Aristotle's law of motion "v α F/R" into "v α F/M" for the case of celestial motion with his auxiliary theory of what may be called celestial inertia M, whereby R = M > 0. But Averroes restricted inertia to celestial bodies and denied sublunar bodies have any inherent resistance to motion other than their gravitational (or levitational) inherent resistance to violent motion, just as in Aristotle's original sublunar physics.

However, Thomas Aquinas, also a student of Aristotelianism, rejected this denial of sublunar inertia and extended Averroes' innovation in the celestial physics of the spheres to all sublunar bodies. He posited all bodies universally have a non-gravitational inherent resistance to motion constituted by their magnitude or mass. In his Systeme du Monde, the pioneering historian of medieval science Pierre Duhem, stated:

"For the first time we have seen human reason distinguish two elements in a heavy body: the motive force, that is, in modern terms, the weight; and the moved thing, the corpus quantum, or as we say today, the mass. For the first time we have seen the notion of mass being introduced in mechanics, and being introduced as equivalent to what remains in a body when one has suppressed all forms in order to leave only the prime matter quantified by its determined dimensions. Saint Thomas Aquinas's analysis, completing Ibn Bajja's, came to distinguish three notions in a falling body: the weight, the mass, and the resistance of the medium, about which physics will reason during the modern era....This mass, this quantified body, resists the motor attempting to transport it from one place to another, stated Thomas Aquinas."

Some five centuries after Averroes' and Aquinas' innovations, it was Johannes Kepler who first dubbed this non-gravitational inherent resistance to motion in all bodies universally 'inertia'. Hence the crucial notion of 17th century early classical mechanics of a resistant force of inertia inherent in all bodies was born in the heavens of medieval astrophysics, in the Aristotelian physics of the celestial spheres, rather than in terrestrial physics or in experiments.

However, having discounted the possibility of any resistance due to a contrary inclination to move in any opposite direction or due to any external resistance, in concluding their impetus was therefore not corrupted by any resistance, Jean Buridan also discounted any inherent resistance to motion in the form of an inclination to rest within the spheres themselves, such as the inertia posited by Averroes and Aquinas. For otherwise, that resistance would destroy their impetus, as the anti-Duhemian historian of science Annaliese Maier maintained the Parisian impetus dynamicists were forced to conclude, because of their belief in an inherent inclinatio ad quietem (tendency to rest) or inertia in all bodies. But in fact, contrary to that inertial variant of Aristotelian dynamics, according to Buridan, prime matter does not resist motion.

Law and jurisprudence

As a Qadi (judge), Ibn Rushd wrote the Bidāyat al-Mujtahid wa Nihāyat al-Muqtasid, a Maliki legal treatise dealing with Sharia (law) and Fiqh (jurisprudence) which, according to Al-Dhahabi in the 13th century, was considered the best treatise ever written on the subject. Ibn Rushd's summary the opinions (fatwa) of previous Islamic jurists on a variety of issues has continued to influence Islamic scholars to the present day, notably Javed Ahmad Ghamidi. While Ibn Rushd himself claimed that women in Islam were equal to men in all respects and possessed equal capacities to shine in peace and in war, he summarized the opinions of previous jurists and Imams on the status of women's testimony in Islam as follows:

"There is a general consensus among the jurists that in financial transactions a case stands proven by the testimony of a just man and two women on the basis of the verse: ‘If two men cannot be found then one man and two women from among those whom you deem appropriate as witnesses’. However; in cases of Hudud, there is a difference of opinion among our jurists. The majority say that in these affairs the testimony of women is in no way acceptable whether they testify alongside a male witness or do so alone. The Zahiris on the contrary maintain that if they are more than one and are accompanied by a male witness, then owing to the apparent meaning of the verse their testimony will be acceptable in all affairs. Imam Abu Hanifah is of the opinion that except in cases of Hudud and in financial transactions their testimony is acceptable in bodily affairs like divorce, marriage, slave-emancipation and raju‘ [restitution of conjugal rights]. Imam Malik is of the view that their testimony is not acceptable in bodily affairs. There is however a difference of opinion among the companions of Imam Malik regarding bodily affairs which relate to wealth like advocacy and will-testaments which do not specifically relate to wealth. Consequently, Ash-hab and Ibn Majishun accept two male witnesses only in these affairs, while to Malik Ibn Qasim and Ibn Wahab two female and a male witness are acceptable. As far as the matter of women as sole witnesses is concerned, the majority accept it only in bodily affairs, about which men can have no information in ordinary circumstances like the physical handicaps of women and the crying of a baby at birth."

He also discussed Islamic economic jurisprudence, particularly the concept of Riba (usury). He reported that Ibn ‘Abbas, a sahaba (companion) of Muhammad, did not accept Riba al-Fadl (interest in excess) because, according to him, the Prophet Muhammad had clarified that there was no Riba except in credit. He also discussed the role of Islamic criminal jurisprudence in the Islamic dietary laws in regards to the consumption of alcohol. He stated that physical punishment for alcoholic consumption was not originally established as part of the Sharia in Muhammad's time but was later decided by the Shura (consultive council) of the Rashidun Caliphate. He wrote:

"The general opinion in this regard is based on the consultation of ‘Umar (rta) with the members of his Shura. The session of this Shura took place during his period when people started indulging in this habit more frequently. ‘Ali (rta) opined that, by analogy with the punishment of Qadhf, its punishment should also be fixed at eighty stripes. It is said that while presenting his arguments, he had remarked: ‘When he [– the criminal –] drinks, he will get intoxicated and once he gets intoxicated, he will utter nonsense; and once he starts uttering nonsense, he will falsely accuse other people’."

Logic

Ibn Rushd was the last major Muslim logician from Al-Andalus. He is known for writing the most elaborate commentaries on Aristotelian logic.

Medicine

As a physician, Ibn Rushd wrote twenty treatises on Arabic medicine, including a seven-volume medical encyclopedia entitled Kitābu’l Kulliyāt fī al-Tibb (General Rules of Medicine), better known as Colliget in Latin. This encyclopedic work was completed at some time before 1162 and elaborated on physiology, general pathology, diagnosis, materia medica, hygiene and general therapeutics. He argued that no one can suffer from smallpox twice, and fully understood the function of the retina. He improved on Alhazen's Book of Optics (1021) which, though providing a largely correct optical theory on vision, incorrectly assumed the lens of the eye to be the organ of sight. Averroes corrected this by showing that sight is the function of the retina.

His Colliget was largely overshadowed by the earlier medical encyclopedias, Continents by Muhammad ibn Zakariya ar-Razi (Rhazes) and The Canon of Medicine by Ibn Sina (Avicenna). As a result, Averroes' fame as a physician was eclipsed by his own fame as a philosopher. His Kulliyāt was translated into Latin by the Jewish translator Bonacosa in the late 13th century and again by Syphorien Champier in circa 1537, and it was also translated into Hebrew twice. Max Meyerhof notes that the prototypes for the physician-philosophers that predominated in Spain were "Ibn Zuhr (Avenzoar) and Ibn Rushd (Averroes)".

Ibn Rushd discussed the topic of human dissection and autopsy. Although he never undertook human dissection, he was aware of it being carried out by some of his contemporaries, such as Ibn Zuhr (Avenzoar), and appears to have supported the practice. Ibn Rushd stated that the "practice of dissection strengthens the faith"due to his view of the human body as "the remarkable handiwork of God in his creation." Despite his criticism of Al-Ghazali's theological views, Ibn Rushd agreed with him on the issue of anatomy and dissection, and wrote:

"Whoever has been occupied with the science of anatomy/dissection (tashrfh) has increased his belief in God."

In urology, Ibn Rushd identified the issues of sexual dysfunction and erectile dysfunction, and was among the first to prescribe medication for the treatment of these problems. He used several methods of therapy for this issue, including the single drug method where a tested drug is prescribed, and a "combination method of either a drug or food." Most of these drugs were oral medication, though a few patients were also treated through topical or transurethral means.

In neurology and neuroscience, Ibn Rushd suggested the existence of Parkinson's disease, and in ophthalmology and optics, he was the first to attribute photoreceptor properties to the retina.[31] In his Colliget, he was also the first to suggest that the principal organ of sight might be the arachnoid membrane (aranea). His work led to much discussion in 16th century Europe over whether the principal organ of sight is the traditional Galenic crystalline humour or the Averroist aranea, which in turn led to the discovery that the retina is the principal organ of sight.

Music theory

As an Arabic music theorist, Ibn Rushd contributed to music theory with his commentary on Aristotle's On the Soul, where Ibn Rushd dealt perspicuously with the theory of sound. This text was translated into Latin by Michael Scot (d. 1232).

Physics

In Averroes' commentary on Aristotle's Physics, he commented on the theory of motion proposed by Ibn Bajjah (Avempace) in Text 71, and also made his own contributions to physics, particularly mechanics. Averroes was the first to define and measure force as "the rate at which work is done in changing the kinetic condition of a material body" and the first to correctly argue "that the effect and measure of force is change in the kinetic condition of a materially resistant mass." It seems he was also the first to introduce the notion that bodies have a (non-gravitational) inherent resistance to motion into physics, subsequently first dubbed 'inertia' by Johannes Kepler. But he only attributed it to the superlunary celestial spheres, and in order to explain why they do not move with infinite speed as was predicted by the application of Aristotle's general law of motion v α F/R to celestial motion, given the assumption that the spheres have movers and thus F > 0, but no resistance to their motion, whereby R = 0.

John Philoponus had earlier rejected Aristotle's theory of motion because of this celestial empirical refutation in favour of his alternative theory v α F - R that avoided it because v is finite even when R = 0 and when F > 0 and is finite. But contra Philoponus, Averroes restored it by positing inertia instead, whereby R > 0 even in the absence of any external resistance to motion and of any inherent gravitational resistance, as in the quintessential heavens in Aristotelian cosmology. But Averroes denied sublunar bodies have inertia, and it was Thomas Aquinas, also a student of Aristotelianism, who extended this inherent force to terrestrial bodies as well, thus also rejecting Aristotle's prediction that the speed of gravitational fall of all bodies in a vacuum would be infinite because there would be no resistance to motion in the absence of an external resistant medium (i.e. R = 0). For Aristotle had assumed the only inherent resistance to motion in bodies is that of gravity, without which bodies would not inherently resist any motion, and which does not resist gravitational (i.e. 'natural') motion where it acts as the motor rather than as a brake as it does in violent motion. The Averroes-Aquinas notion of inertia was eventually adopted by Kepler, but not by scholastic Aristotelian impetus dynamics nor Galileo Galilei who maintained like Jean Buridan, for example, that prime matter does not inherently resist any motion and so is indifferent to motion or rest. It eventually became the central concept of Newton's dynamics in its notion of the inherent force of inertia in all bodies, with the minor revision that the force of inertia resists all motion except for uniform straight motion, a purely fictitious ideal motion whose perseverance it would cause. But Newton's inherent force of inertia resists all actual motion, given it is all accelerated motion in the Newtonian cosmos populated by many gravitationally attractive massive bodies. Thus on this analysis Averroes is creditable with one of the two most crucial innovations in the history of the development of Aristotelian dynamics into Newtonian dynamics, namely its two auxiliary notions of the force of impetus and of the force of inertia.

Politics

Ibn Rushd did not have access to any text of Aristotle's Politics. As a substitute for this, he commented on Plato's The Republic, arguing that the ideal state there described was the same as the original constitution of the Islamic Caliphate, as well as the Almohad state of Ibn Tumart. He also believed that a wise philosopher should be commander and chief of a nation.

Ibn Rushd also claimed that women were equal to men in all respects and possessed equal capacities to shine in peace and in war, citing examples of female warriors among the Arabs, Greeks and Africans to support his case. In Muslim history, examples of notable female Muslims who fought as soldiers or generals included Nusaybah Bint k’ab Al Maziniyyah, Aisha, Kahula and Wafeira, and Um Umarah.

Psychology

H. Chad Hillier writes the following on Ibn Rushd's contributions to psychology:

There is evidence of some evolution in Ibn Rushd's thought on the intellect, notably in his Middle Commentary on De Anima where he combines the positions of Alexander and Themistius for his doctrine on the material intellect and in his Long Commentary and the Tahafut where Ibn Rushd rejected Alexander and endorsed Themistius’ position that "material intellect is a single incorporeal eternal substance that becomes attached to the imaginative faculties of individual humans." Thus, the human soul is a separate substance ontologically identical with the active intellect; and when this active intellect is embodied in an individual human it is the material intellect. The material intellect is analogous to prime matter, in that it is pure potentiality able to receive universal forms. As such, the human mind is a composite of the material intellect and the passive intellect, which is the third element of the intellect. The passive intellect is identified with the imagination, which, as noted above, is the sense-connected finite and passive faculty that receives particular sensual forms. When the material intellect is actualized by information received, it is described as the speculative (habitual) intellect. As the speculative intellect moves towards perfection, having the active intellect as an object of thought, it becomes the acquired intellect. In that, it is aided by the active intellect, perceived in the way Aristotle had taught, to acquire intelligible thoughts. The idea of the soul's perfection occurring through having the active intellect as a greater object of thought is introduced elsewhere, and its application to religious doctrine is seen. In the Tahafut, Ibn Rushd speaks of the soul as a faculty that comes to resemble the focus of its intention, and when its attention focuses more upon eternal and universal knowledge, it becomes more like the eternal and universal. As such, when the soul perfects itself, it becomes like our intellect.
Ibn Rushd succeeded in providing an explanation of the human soul and intellect that did not involve an immediate transcendent agent. This opposed the explanations found among the Neoplatonists, allowing a further argument for rejecting of Neoplatonic emanation theories. Even so, notes Davidson, Ibn Rushd’s theory of the material intellect was something foreign to Aristotle.

Significance

Averroes, detail of the fresco The School of Athens by Raphael

In the West, Averroes is most famous for commentaries on Aristotle's works, most of which had been inaccessible to Latin Europe during the Early Middle Ages. Before 1100 only a few of Aristotle's logical works had been translated into Latin by Boethius, although the entire extant Greek corpus was known in Byzantium. After Latin translations of Aristotle's other works from Greek and Arabic were made in the 12th and 13th centuries , Aristotle became more influential on medieval European philosophy. Averroes' commentaries on Aristotle contributed to his growing influence in the medieval West.

In medieval Europe, Averroes' school of philosophy, known as Averroism, exerted a strong influence on Christian philosophers such as Thomas Aquinas and Jewish philosophers such as Gersonides and Maimonides. Despite negative reactions from Jewish Talmudists and the Christian clergy, Averroes' writings were taught at the University of Paris and other medieval universities, and Averroism remained the dominant school of thought in Europe through to the 16th century.

Averroes' argument in The Decisive Treatise provided a justification for the emancipation of science and philosophy from official Ash'ari theology, thus Averroism has been regarded as a precursor to modern secularism.

George Sarton, the father of the history of science, writes:

"Averroes was great because of the tremendous stir he made in the minds of men for centuries. A history of Averroism would include up to the end of the sixteenth-century, a period of four centuries which would perhaps deserve as much as any other to be called the Middle Ages, for it was the real transition between ancient and modern methods."

Averroes's work on Aristotle spans almost three decades, and he wrote commentaries on almost all of Aristotle's work except for Aristotle's Politics, to which he did not have access. Averroes' philosophical works had less influence on the medieval and early modern Islamic world than the contemporaneous Latin Christian world, as indicated by the fact many of them works did not survive in the original Arabic but rather in Latin and Hebrew translation. However, his works on specifically Islamic topics such as fiqh (Islamic law), which were not translated into Latin, naturally influenced the Islamic world rather than the West. His death coincides with a change in the culture of Al-Andalus. In his work Fasl al-Maqāl (translated a. o. as The Decisive Treatise), he stresses the importance of analytical thinking as a prerequisite to interpret the Qur'an; this is in contrast to orthodox Ash'ari theology, where the emphasis is less on analytical thinking but on extensive knowledge of sources other than the Qur'an, i.e. the hadith.

Hebrew translations of his work also had a lasting impact on Jewish philosophy, in particular Gersonides, who wrote supercommentaries on many of the works. In the Christian world, his ideas were assimilated by Siger of Brabant and Thomas Aquinas and others (especially in the University of Paris) within the Christian scholastic tradition which valued Aristotelian logic. Famous scholastics such as Aquinas believed him to be so important they did not refer to him by name, simply calling him "The Commentator" and calling Aristotle "The Philosopher." Averroes's treatise on Plato's Republic has played a major role in both the transmission and the adaptation of the Platonic tradition in the West. It has been a primary source in medieval political philosophy. On the other hand he was feared by many Christian theologians, who accused him of advocating a "double truth" and denying orthodox doctrines such as individual immortality, and an underground mythology grew up stigmatising him as the ultimate unbeliever; these accusations were largely based on misunderstandings of his work.

A later importation of Averroism into Europe is associated with the University of Padua in the early Renaissance, important names being Zabarella, Cremonini and Niphus.

Cultural influences

Commentarium magnum Averrois in Aristotelis De Anima libros. French manuscript, third quarter of the 13th century

Reflecting the respect which medieval European scholars paid to him, Averroes is named by Dante in The Divine Comedy with the great pagan philosophers whose spirits dwell in "the place that favor owes to fame" in Limbo.

Averroes appears in a short story by Jorge Luis Borges, entitled "Averroes's Search", in which he is portrayed trying to find the meanings of the words tragedy and comedy. He is briefly mentioned in the novel Ulysses by James Joyce alongside Maimonides. He appears to be waiting outside the walls of the ancient city of Cordoba in Alamgir Hashmi's poem In Cordoba. He is also the main character in Destiny, a Youssef Chahine film. The Muslim pop musician Kareem Salama composed and performed a song in 2007 titled Aristotle and Averroes.

Averroes is also the title of a play called "The Gladius and The Rose", written by Tunisian writer Mohamed Ghozzi, and which had the first price in the theater festival in Charjah in 1999.

The asteroid "8318 Averroes" was named in his honor.

A movie depicting the life and times of Averroes was released in 1998, titled Destiny (1997 film).

List of works

Logic

Short Commentary

  • [1] Short Commentary on Aristotle's Organon / Tajrīd al-ʾaqāwīl al-ḍarūrīya min ṣināʿat al-manṭiq (Aka: Al-ḍarūrī; Al-ḍarūrī fī l-manṭiq; Kitāb fī l-manṭiq; Muḫtaṣar fī l-manṭiq) ca. 552/1157

Middle Commentaries

  • [2] Middle Commentary on the Isagoge / Talḫīṣ madḫal fī Fūrfūrīyūš (Aka: Talḥīṣ kitāb ʾĪsāġūjī)

Talḫīṣ kitāb ʾArisṭū fī l-manṭiq

  • [3] Middle Commentary on the Categories / Talḫīṣ kitāb al-maqūlāt
  • [4] Middle Commentary on Peri hermeneias / Talḫīṣ kitāb al-ʿibāra
  • [5] Middle Commentary on the Prior Analytics / Talḫīṣ kitāb al-qiyās
  • [6] Middle Commentary on the Posterior Analytics / Talḫīṣ kitāb al-burhān (Aka: Talḫīṣ kitāb al-burhān li-ʾArisṭūṭālīs; Talḫīṣ kitāb al-burhān lahū)
  • [7] Middle Commentary on the Topics / Talḫīṣ kitāb al-jadal
  • [8] Middle Commentary on the Sophistici Elenchi / Talḫīṣ kitāb al-safsaṭa
  • [9] Middle Commentary on the Rhetoric / Talḫīṣ al-ḫiṭāba [570/1175 or 571/1176]
  • [10] Middle Commentary on the Poetics / Talḫīṣ kitāb al-šiʿr

Long Commentaries

  • [11] Long Commentary on the Prior Analytics (?) / Šarḥ kitāb al-qiyās li-ʾArisṭūṭālīs (Aka: Kitāb šarḥ kitāb al-qiyās li-ʾArisṭū)
  • [12] Long Commentary on the Posterior Analytics / Šarḥ kitāb al-burhān

Questions

  • [13] Questions on Logic / Quæsita in libros logicæ Aristotelis (Part of: Masāʿil fī l-ḥikma, aka: Muqaddimāt fī l-ḥikma)
Questions on the Isagoge
  • [13.1] On Alfarabi on the Isagoge about genus and differentia / Kalām ʿalā qawl ʾAbī Naṣr fī l-madḫal wa-l-jins wa-l-faṣl yuštarikān
Questions on the Categories
  • [13.2] On substantial and accidental universals / Al-qawl fī kullīyāt al-jawhar wa-kullīyāt al-ʾaʿraḍ (Aka: Bāb ʿalā maqūla ʾawwal kitāb ʾAbī Naṣr (?), Maqāla ʿalā ʾawwal maqūla ʾAbī Naṣr (?))
Questions on Peri hermeneias
  • [13.3] On the copula and on derived nouns / Maqāla fī l-kalima wa-l-ism al-muštaqq (Aka: Kalām lahū ʿalā l-kalima wa-l-ism al-muštaqq, Min kitāb al-ʿibāra li-ʾAbī Naṣr)
  • [13.4] On compound and simple predicates / Min kitāb al-ʿibāra (Aka: De prædicatis compositis et divisis)
Questions on the Prior Analytics
  • [13.5] On the definition: Critique of the positions of Alexander and Alfarabi / Al-qawl fī l-ḥadd wa-naqd mā ḏahaba ʾilayhī al-ʾIskandar wa-ʾAbū Naṣr (Aka: Maqāla fī l-ḥadd (juzʾ al-qiyās) wa-naqd maḏahabay al-ʾIskandar wa-ʾAbī Naṣr; De definitione termini)
  • [13.6] Critique of Avicenna's position on the conversion of premises / Naqd maḏhab Ibn Sīnā fī inʿikās al-qaḍāyā (Aka: Maqāla fī naqd maḏhab Ibn Sīnā fī ʿaks al-qaḍāyā; De conversionibus)
  • [13.7] Critique of Themistius's position on the contingent syllogisms in the first and second figure / Naqd maḏhab Tāmisṭiyūs fī l-maqāyīs al-mumkina fī l-šaklayn al-ʾawwal wa-l-ṯānī (Aka: De conditione syllogismorum contingentium circa duo eorum attributa, videlicet de numerositate illationis, et de figura in qua non concludunt)
  • [13.8] Chapter on absolute premises / Maqāla fī l-muqaddima al-muṭlaqa (Aka: Quid sit propositio absoluta id est de inesse)
  • [13.9] On the types of conclusions in compound syllogisms / Al-qawl fī jihāt al-natāʾij fī l-maqāyīs al-murakkaba wa-fī maʿnā al-maqūl ʿalā l-kull
  • [13.10] Chapter on the dependency of the types of conclusions from the types of premises / Maqāla [...] fī luzūm jihāt al-natāʾij li-jihāt al-muqaddimāt
  • [13.11] On the mixing of contingent and necessary premises / De mistione contingentis et necessarii
  • [13.12] Chapter on the dependency of the conclusions from mixed syllogisms
  • [13.13] Chapter on the meaning of "predicated on everything" / Maqāla [...] fī maʿnā al- maqūl ʿalā l-kull wa-ġayr ḏālika
  • [13.14] Chapter on conditional syllogisms / Maqāla fī l-maqāʾis al-šarṭīya (Aka: Maqāla fī l-qiyās; De conditionali, an per ipsum ostendatur quæsitum primum ignotum)
  • [13.15] Exposition of Alfarabi's commentary on the first book of the Prior Analytics / Talḫīṣ šarḥ ʾAbī Naṣr [li-]l-maqāla al-ʾūlā min al-qiyās li-l-ḥakīm...
Questions on the Posterior Analytics
  • [13.16] On the predicates in demonstrations / Al-qawl fī l-maḥmūlāt al-barāhīn (Aka: Epistola de primitate prædicatorum in demonstrationibus)
  • [13.17] On Alfarabi's Book on Demonstration / Min kitāb al-burhān li-ʾAbī Naṣr
  • [13.18] On the definition of individuals / Al-qawl fī ḥadd al-šaḫṣ (Aka: An definitio sit particularis aut universalis tantum)
  • [13.19] On the three types of definition in relation to demonstrations / De triplici genere diffinitionum in ordine ad demonstrationem
  • [13.20] On whether the middle term is the cause of the major term / De medio demonstrationis an sit causa maioris extremi
  • [13.21] Treatise on the disagreement of Alfarabi and Aristotle on the order of the Posterior Analytics and the rules of demonstrations and definitions / Kitāb fī mā ḫālafa ʾAbū Naṣr li-ʾArisṭū fī kitāb al-burhān min tartībihī wa-qawānīn al-barāhīn wa-l-ḥudūd (Aka: De conditionibus præmissarum demonstrationis)
  • [13.22] On the conditions for the necessity of the premises of demonstrations / De conditionibus quæ requiruntur ad necessitatem præmissarum demonstrationum
  • [13.23] On how a demonstration can be transferred from one science to another / Quomodo fiat translatio ab una arte in aliam
  • [13.24] On demonstrations quia / De demonstrationibus quia
  • [13.25] On the sense in which the definition is better known than the thing defined / Quomodo definitio sit notior ipso definito
  • [13.26] On the definitions which are said to differ from demonstrations in their order / De definitionibus quæ dicuntur positione differentes a demonstratione

Philosophy of Nature

Physics

  • [14] Short Commentary on the Physics / Jawāmiʿ al-samāʾ al-ṭabīʿī (Part of: Al-jawāmiʿ fī l-falsafa; Jawāmiʿ kutub ʾArisṭūṭālīs fī l-ṭabīʿīyāt wa-l-ʾilāhīyāt)
  • [15] Middle Commentary on the Physics / Talḫīṣ kitāb al-samāʾ al- al-ṭabīʿī (Aka: [...] li-ʾArisṭūṭālīs; Talḫīṣ al- ṭabīʿī; Wa-laḫaṣa kitāb al-samāʿ al-ṭabīʿī li-ʾArisṭūṭālīs)
  • [16] Long Commentary on the Physics / Šarḥ [kitāb] al-samāʾ al-ṭabīʿī

On the Heavens

  • [17] Short Commentary on De cælo / Jawāmiʿ al-samāʾ wa-l-ʿālam (Part of: Al-jawāmiʿ fī l-falsafa; Jawāmiʿ kutub ʾArisṭūṭālīs fī l-ṭabīʿīyāt wa-l-ʾilāhīyāt)
  • [18] Middle Commentary on De cælo / Talḫīṣ [kitāb] al-samāʾ wa-l-ʿālam
  • [19] Long Commentary on De cælo / Šarḥ kitāb al-samāʾ wa-l-ʿālam (Aka: Šarḥ kitāb al-samāʾ wa-l-ʿālam li-ʾArisṭūṭālīs; Šarḥ al-samāʾ wa-l-ʿālam)
  • [20] De substantia orbis

On Generation and Corruption

  • [21] Short Commentary on De generatione et corruptione / Jawāmiʿ kitāb al-kaun wa-l-fasād (Part of: Al-jawāmiʿ fī l-falsafa; Jawāmiʿ kutub ʾArisṭūṭālīs fī l-ṭabīʿīyāt wa-l-ʾilāhīyāt)
  • [22] Middle Commentary on De generatione et corruptione / Talḫīṣ [kitāb] al-kaun wa-l-fasād 567/1172

Meteorology

  • [23] Short Commentary on the Meteorology / Jawāmiʿ kitāb al-ʾaṯār al-ʿulwīya (Part of: Al-jawāmiʿ fī l-falsafa; Jawāmiʿ kutub ʾArisṭūṭālīs fī l-ṭabīʿīyāt wa-l-ʾilāhīyāt)
  • [24] Middle Commentary on the Meteorology / Talḫīṣ [kitāb] al-ʾāṯār al-ʿulwīya

[edit] Biology

  • [25] Middle(?) Commentary on De animalibus / Talḫīṣ tisʿ maqālāt min kitāb al-ḥayawān (Aka: Talḫīṣ tisʿ maqālāt min kitāb al-ḥayawān wa-ḏālika min al-ḥādīya ʿašr ʾilā ʾāḫar al-diwān; Talḫīṣ fī l-maqāla al-ḥādīya ʿašara min kitāb al-ḥayawān li-ʾArisṭūṭālīs wa-ḏālika tisʿ maqālāt; Kitāb al-ḥayawān) 565/1169
  • [26] Chapter on animals / Maqāla fī l-ḥayawān (Aka: Kalām lahū ʿalā l-ḥayawān)
  • [27] Short Commentary on De plantis

Questions

  • [28] Questions on the Philosophy of Nature / Sefer ha-derušim ha-ṭibʿiyim

Psychology

Commentaries

  • [29] "Book on the Soul" or Short Commentary on De anima / Kitāb al-nafs
  • [30] Middle Commentary on De anima / Talḫīṣ kitāb al-nafs 577/1181
  • [31] Long Commentary on De anima / Šarḥ kitāb al-nafs (Aka: Šarḥ kitāb al-nafs li-ʾArisṭūṭālīs)
  • [32] Commentary on the Parva naturalia / Talḫīṣ al-ḥiss wa-l-maḥsūs. Sevilla, 13. Rabīʿ al-ʾāḫar 565 [ca. 01/04/1170]

Treatises on the Intellect

  • [33] Enquiry whether the intellect in us, named the material intellect, is able to know in the end the separate forms or not =Epistle on the possibility of conjunction / Kitāb fī l-faḥṣ hal yumkin al-ʿaql ʾallaḏī fīnā wa-huwa al-musammā bi-l-hayūlānī ʾan yaʿqila al-ṣuwar al-mufāriqa bi-ʾāḫirihī ʾau lā yumkin ḏālika wa-huwa al-maṭlūb ʾallaḏī kāna ʾArisṭūṭālīs waʿadanā bi-l-faḥṣ ʿanhū fī kitāb al-nafs (Aka: ʾIggeret ʾefšarut ha-debequt)
  • [34] Chapter on the conjunction of the separate intellect with man / Maqāla fī ttiṣāl al-ʿaql al-mufāriq bi-l-ʾinsān (Aka: Masʾala fī ʿilm al-nafs suʾila ʿanhā fa-ʾajāba fīha; Epistola de connexione intellectus abstracti cum homine)
  • [35] Chapter on the conjunction of intellect with man / Maqāla fī ttiṣāl al-ʿaql bi-l-ʾinsān (Aka: Maqāla ʾaiḍan fī ttiṣāl al-ʿaql bi-l-ʾinsān; Maqāla fī ḏālika ʾaiḍan)
  • [36] Chapter on the intellect / Maqāla fī l-ʿaql (Aka: Maqāla ʾuḫrā fī ʿilm al-nafs ʾaiḍan)
  • [37] Commentary on Alexander's treatise on the intellect / Šarḥ maqālat al-ʾIskandar fī l-ʿaql
  • [38] Commentary on Avempace's epistle on the conjunction of the intellect with man / Šarḥ risālat ittiṣāl al-ʿaql bi-l-ʾinsān li-bn al-Ṣāʾiġ

ʿAbd Allāh Ibn Rušd (son of Averroes)

  • [39] On whether the active intellect unites with the material intellect whilst it is clothed with the body / Hal yattaṣilu bi-l-ʿaql al-hayūlānī al-ʿaql al-faʿʿāl wa-huwa multabis bi-l-jism

Anonymous

  • [40] De animæ beatudine / Tractatus Aueroys de perfectione naturali intellectus secundum mentem philosophi

Metaphysics

Commentaries

  • [41] Short Commentary on the Metaphysics / Jawāmiʿ kitāb mā baʿd al-ṭabīʿa (Part of: Jawāmiʿ kutub ʾArisṭūṭālīs fī l-ṭabīʿīyāt wa-l-ʾilāhīyāt; Al-gawāmiʿ fī l-falsafa)
  • [42] Middle Commentary on the Metaphysics / Talḫīṣ mā baʿd al-ṭabīʿa (Aka: Talḫīṣ kitāb mā baʿd al-ṭabīʿa li-ʾArisṭūṭālīs; Kitāb talḫīṣ mā baʿd al-ṭabīʿa li-ʾArisṭūṭālīs; Averrois in septem libros media expositio ab Hælia Cretensi in latinum conversa, Ante hac nunquam excusa, summis vigiliis elaborata) Cordova, 25. Rabīʿ al-ʾāḫar 570 [11/23/1174].
  • [43] Long Commentary on the Metaphysics / Šarḥ mā baʿd al-ṭabīʿa.

Practical Philosophy

Mathematics