On Medicine
WHO’S WHO IN PHILOSOPHY 259
ESSENTIAL TEXTS The Book of Healing (Kitab al-shifa); Canon of Medicine (Al-qanun fil-tibb).
Avicenna (Ibn Sina)
b 980–1037 n Persia
Avicenna’s philosophical system is a synthesis of Neo- Platonic and Aristotelian traditions with Muslim theology.
A key philosopher of the Middle Ages, he was equally signifi cant in the sciences. His Canon of Medicine was the main medical textbook used throughout medieval Europe.
Avicenna the physician attempts to correct spinal curvature in a patient.
LIFE AND WORKS
Avicenna’s philosophy is a refi nement of that of al-Farabi (see p.258), although his approach tends to downplay the Neo- Platonic elements in favor of Aristotle.
Developing Plotinus’s idea of a hierarchy of being from the One, or Allah, down to the world of matter, he argued that all human souls are immortal and that the intellectual pursuit of the intelligible world was the route to ultimate union with Allah and a better afterlife.
THE KALAM ARGUMENT Along with other Muslim philosophers of the period, Avicenna propounded a version of the cosmological argument for God’s existence (see p.142) known as the
“Kalam argument,” which derives ultimately from Aristotle. It begins from the observation, gained from al-Farabi, that all things in the universe are possible beings, meaning that they might not have existed and have no inherent reason for existing. The “essence” of such beings is said to be distinct from their “existence,” so the fact that they exist is not determined by what they are. Therefore they must depend on something else for their existence, and must be caused to exist by something else. However, this cannot be true of everything that exists, otherwise there would be an infi nite regress and no ultimate ground for the existence of anything. It follows that there must be a being whose existence is necessary, which is its own cause and sustains everything else in existence: namely Allah.
As a necessary and perfect being, Allah cannot change, and so is eternal. Allah cannot have acted to create the universe as this would involve change, and therefore, for Avicenna, the universe
“emanates” of necessity from the nature of Allah. In this he follows the Neo- Platonist idea that all being emanates from God as its sustaining cause. But this view raises certain theological diffi culties for both Islamic and Christian thinkers, as it is in tension with the Koranic and Biblical accounts of the Creation. Also, if the universe emanates from God, then everything is necessary. This implies that events and actions are predetermined, thus problematizing ideas of moral responsibility and divine justice.
SEE ALSO 왘 Does God exist? (pp.140–9) A crater on the Moon has been named after Avicenna (the Latinized name of Ibn Sina) in recognition of his remarkable achievements as an astronomer and scientist.
Among his scientifi c claims that have proved correct is that sight is not a power of the eye to grasp an object, but that a source of light emits luminous particles that travel at a fi nite speed and that the eye picks up. He also observed the silhouette of the planet Venus against the Sun and thereby correctly inferred that Venus must be closer to the Sun than is the Earth.
AVICENNA THE SCIENTIST
Theological tensions exist between Avicenna’s ideas and the teachings of the Koran.
KEY IDEAS
WHO’S WHO IN PHILOSOPHY 261
Anselm left his family home in Aosta in Piedmont at the age of 23, with the intention of becoming a monk, and after some years of traveling, he joined the Benedictine Abbey at Bec in Normandy, France. He rose swiftly through the ranks and was made Abbot in 1078. Bec was a powerful monastery and a major seat of learning. As Abbot, Anselm traveled frequently to England and, in 1093, was appointed Archbishop of Canterbury, head of the Church of England.
Anselm summed up his philosophical enterprise as “faith seeking under- standing,” meaning that reason deepens one’s grasp of truths established by
Born in Tus in modern-day Iran, al-Ghazali rose to become one of the most celebrated scholars of the golden era of Islamic philosophy. His lectures at the Nizamiyyah school drew in hundreds of scholars and brought al-Ghazali great wealth and respect.
Eventually he began to regard the views in The Opinions as un-Islamic, and produced a sceptical companion work, The Incoherence of the Philosophers, which set about refuting them by using philosophical argument rather than appealing to faith. This attack on philosophical reason was suffi ciently powerful for Averroes (see p.263) to feel the need to produce an extended defense in the Incoherence of the Incoherence.
revelation. He devised various arguments in support of the main articles of the Christian faith, such as the Trinity and the Atonement. But Anselm is best known as the inventor of the “ontological argument” (see pp.140–1), which appears in the Proslogion. This argument does not just try to establish the existence of the greatest conceivable being, but also the various attributes that God must have in virtue of being the greatest: that he is omnipotent, omniscient, self-existent, and so on. Despite having powerful detractors, including Aquinas and Kant, debate over Anselm’s argument has resurfaced in recent years.
Anselm of Canterbury
b 1033–1109 n Italy
A gifted scholar, Anselm produced his masterpiece, the Proslogion, in 1078. He became Archbishop of Canterbury, and held the position until his death, despite long power struggles with the Crown which forced him into exile several times.
Al-Ghazali
b 1058–1111 n Persia
Al-Ghazali was head of the prestigious Nizamiyyah school in Baghdad from 1092 to 1096, when he wrote The Opinions of the Philosophers, expounding the Neo-Platonist and Aristotelian views of Islamic scholars, including al-Farabi and Avicenna.
After some years al-Ghazali resigned his post at the Nizamiyyah school, gave away his wealth, and took up a spiritual journey as a wandering Sufi in the holy lands. His autobiography, The Delivery from Error, suggests that this decision followed his recognition that revealed truth cannot be discovered by philosophical argument, but only through devoting oneself to mystical practices. He later returned to teaching and to his home of Tus, where he spent his fi nal years.
Interest today in the work of al-Ghazali often focuses on his analysis of causality, in which he denies direct material causes between events, arguing that causal regularities are made possible by the will of God.
Abelard attended the Cathedral School of Nôtre Dame, Paris. He was a brilliant student, and became a charismatic teacher. By the age of 22 he had set up his own school in Paris, and went on to acquire the Chair at Nôtre Dame aged just 34.
Renowned for his skills in dialectic, Abelard stood against the popular realist approach, stating that universal terms, such as
“oak tree,” are just words
that do not denote anything real over the many particular oaks that exist.
Abelard met Hélọse in 1117, when she was just 16. She became pregnant and gave birth to a son named Astrolabe.
Pierre Abelard
b 1079–1142 n France
Remembered less for his philosophy than for his tragic love affair with his pupil Hélọse, Pierre Abelard was nevertheless a remarkable scholar and teacher. A proponent of the Scholastic method of philosophy, he opposed the dominant realist position on universals inherited from Plato (see pp.244–7).
Maimonides came from a line of Jewish scholars and studied the Torah under his father. Although they lived under a liberal Islamic regime in Andalusia, its fall to the conquering Almohades in 1148 forced the family into exile, fi rst in Spain and then, from 1158 on, in Morocco.
They eventually settled in Egypt, where Maimonides became physician to the Wazir of the Sultan Saladin.
The Guide for the Perplexed is an attempt to ground Jewish theology in Aristotelianism, while at the same time
Moses Maimonides
b 1135–1204 n Spain
Maimonides wrote on Jewish law as well as medicine, but philosophers remember him for his Guide for the Perplexed.
The Guide exerted considerable infl uence on medieval Scholasticism, in particular on Aquinas and Duns Scotus.
departing from Aristotle where he is in confl ict with scripture. The Guide offers various proofs for the existence of God and determines some of his attributes—for example, that he is not corporeal. With these proofs, Maimonides defended a form of
“negative theology:” that is, the idea that we cannot do justice to God by describing him in anthropomorphic terms, and since no predicate is adequate, we can only approach a description of him obliquely, via what he is not.
They married in secret, but when the marriage became public, Abelard sent Hélọse off to become a nun. Her family castrated him in revenge and Abelard became a monk. Some of the letters that the two exchanged have survived, and the affair has become one of the great romance stories of European literature.
Abelard continued to court controversy and make enemies—his work was condemned as heretical in 1121, and in 1132 he survived an attempt on his life. He summed up his life in his History of My Misfortunes of 1132. Eventually he left the monastery and became a hermit.
The lovestruck Hélọse of romantic legend was also herself a brilliant scholar; she was to become abbess of her convent.
Averroes (left), imagined in conversation with Porphyry, the great third-century Neo-Platonist teacher and author.
WHO’S WHO IN PHILOSOPHY 263
LIFE AND WORKS
KEY IDEAS
SEE ALSO Reason and faith (p.157) • Al-Ghazali (p.261) • Avicenna (p.259) • Plotinus (pp.254–5)
• Plato (pp.244–7) • Aquinas (pp.264–5)
Averroes lived in Andalusia at the time of Islamic rule when intellectuals enjoyed comparative freedom from political interference. Descended from a family of judges, he was educated in law and medicine as well as theology and philosophy. He became a judge in Seville and Córdoba in 1169 and was subsequently court physician to the Caliph of Córdoba. During this latter
period he produced his extensive commentaries—38 in all—on Aristotle.
The Incoherence of the Incoherence was a refutation of al-Ghazali’s defense of orthodox Islamic teaching against the Aristotelian and Platonic elements in much scholarship. Averroes’s defense of philosophical reason brought him into confl ict with the clerics and in 1195 he was accused of heresy and banished.
Averroes’s philosophy is essentially Aristotelian with Neo-Platonic elements.
In common with other Islamic thinkers of the era, he held that the universe is organized as a hierarchy, with Allah, who is pure form, at one end and formless matter at the other. Allah is the supreme good and that to which the human soul aspires to acquire knowledge. However, contrary to al-Ghazali, he claimed that there are distinct routes to the acquisition of such knowledge: revelation and reason.
Thus, in The Incoherence of the Incoherence, Averroes attacked al-Ghazali’s attempt to show that reason is incapable of demonstrating key metaphysical truths, and thereby reinstated the claims of philosophy to adjudicate on theological issues. This is not to say that revelation has no
place: simply that there are different paths to the truth. Averroes held the view that what is immortal in human beings is a universal soul—that is, one shared by all. So there is a collective immortality, but no personal survival: an idea reminiscent of Buddhism and anathema to later Christian thinkers.
Averroes (Ibn Rushd)
b 1126–1198 n Spain
Averroes, the last of the great philosophers of Islam’s golden era, was the greatest commentator on Aristotle.
His work led to the rediscovery of Aristotle by medieval Christian thinkers, and it is here that it had most infl uence, as Islamic religious study turned away from philosophy.
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Such as that God exists.”
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Born in the kingdom of Naples to a noble family, Thomas Aquinas began his education at the monastery of Monte Cassino at the age of fi ve. He subsequently studied at Naples, where he discovered Aristotle, and in around 1243 he resolved to join the Dominican order.
In an effort to dissuade him from this route, Aquinas’s brothers kidnapped and imprisoned him for two years. Among other methods, they tried to tempt him with a prostitute, but Thomas drove her away with a fi rebrand and burned a crucifi x on his door. When his brothers fi nally relented, Aquinas joined the order and was sent to study under the Aristotelian teacher Albertus Magnus in Cologne and Paris. He remained under Albertus’s tutelage for many years until, in 1257, he attained his master’s degree and license to teach.
AQUINAS THE TEACHER
Aquinas traveled and taught in various European centers of learning, engaged actively in the theological controversies of the day, and wrote prolifi cally. However, on December 6, 1273, he had a mystical experience and stopped writing (leaving his great work the Summa Theologiae unfi nished), saying that all he had written seemed like straw compared to what had been revealed to him. Four months later, the Pope ordered him to attend the Council of Lyons, but during the journey, he was taken ill and died.
Although Aquinas was sometimes dubbed “the dumb ox” because of his slowness of speech and his stocky build, his intellect and character impressed all around him. His teacher Albertus Magnus was prophetic in saying that
“one day the bellowing of this ox will resound throughout the world,” and in 1323, Thomas Aquinas was pronounced a saint by Pope John XXII. His Scholastic philosophy has received a resurgence of attention in recent years.
Thomas Aquinas is considered by many to be the greatest theologian of the Catholic Church. His brand of philosophy, called “Thomism,”
still informs Catholicism today.
AQUINAS 265
LIFE AND WORKS
Thomas Aquinas
b 1225–1274 n Italy
The rediscovery of Aristotle’s works after the Dark Ages (500–1000) ushered in a new era of intellectual endeavor in Europe. Aquinas was the most important fi gure in this reawakening, and his work has remained the intellectual underpinning for the metaphysical, cosmological, and ethical commitments
of the Catholic Church to this day.
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ESSENTIAL TEXTS Summa contra Gentiles;
Summa Theologiae;
commentaries on Aristotle.
Aquinas believed the mind at birth to be a “tabula rasa” or blank slate, and so all our knowledge must come to us from our sense-experience. He distinguished two distinct avenues by which we can acquire knowledge. One is to reason on the basis of evidence gleaned from the world around us. The other is revelation. But while Aquinas drew a clear division between what he termed “natural” and
“revealed” theology, he believed that their discoveries ought to be compatible, for both represent God-given routes to the discovery of the same reality. So it is unsurprising that he should regard the
work of the great pagan philosopher Aristotle, properly interpreted, as ultimately consonant with Christian teaching; and this is why he devoted much of his intellectual energies to the construction of a resolution between these two systems of thought.
ESSENCE AND EXISTENCE Aquinas inherited from Aristotle an interest in being, and he adheres to the notion that each thing has an “essence”
or defi ning characteristic that makes it the thing that it is. But the question of what something is, the question of its essence,
is distinct from that of whether it is, the question of its existence. A unicorn may,
for example, be defi ned as a one- horned horse: this is its essence; but knowing this tells us nothing about
whether or not any exist. The essences of all things in the created world can
be said to precede their existence, meaning that God would have had the idea of it in mind before it was created. However, God’s essence is the only one that did not precede his
existence and so he is the only being for whom the fact that he is and
what he is are identical.
DOES GOD EXIST?
Although God’s existence is revealed to us in the Bible,
and can be accepted on faith, Aquinas believed his
existence could also be KEY IDEAS