The Islamic Keepers of Science
This second fall of Italy as a world leader of science (the first being the fall of the Roman Empire) was not unlike what had happened to the Islamic Empire at the very dawn of the Renaissance. Through the long centuries of the Dark Ages, it was not Christianity but Islam that had kept the flame of science alive. Turkish Ottoman muskets and superior military technology had conquered the Balkans, Ukraine, Crimea, Palestine, Lebanon, Syria, Arabia, and much of North Africa, creating a vast Ottoman empire. Scholars in this golden age of Islam laid the foundation for much of modern Western thinking in ways few people realize today, down to the language and the numerical and mathematical systems we use. The word algebra, for instance, comes from al-gabr, Arabic for “completion,” one of two ways of solving quadratic equations developed by “the father of algebra,” Muhammad ibn Musa al-Khwārizmī, whose last name (al-Khwārizmī), when translated into Latin, is Algoritmi, the root of the word algorithm.
Baghdad’s House of Wisdom madrasa, where al-Khwārizmī taught, was the largest university and the greatest repository of books in the medieval world. Its scholars studied the ancient Greek, Persian, and Sanskrit texts and, based on what they learned there, developed their own science in astronomy, cartography, chemistry, geography, mathematics, medicine, and zoology. In fact, the approach of using the empirical observation of nature to discover the objective truth of things was first used not by Francis Bacon but by an eminent Islamic scientist, Ibn al-Haytham.
It was al-Haytham’s Optics and other Arabic texts, translated into Latin, that informed and inspired the early European thinkers of the Renaissance. The first English astronomer, Walcher of Malvern, noted for using an astrolabe to measure the time of several solar and lunar eclipses, was also the first English scholar of Arabic and one of the first translators of Arabic treatises into Latin (from which he likely learned much of his science), in the late eleventh century. Roger Bacon, the thirteenth-century scientist and Franciscan friar, described a cycle of observation, hypothesis, experimentation, and independent verification, which sounds an awful lot like the modern scientific method, and which he got from studying Optics. Al-Haytham is the first scientist we know of, as the term is used today, to describe someone guided by empirical observation of nature. Optics, written between 1028 and 1038, was translated into Latin and printed in Europe in 1572, and was read by the most influential scientists of the day, including Kepler, Galileo, and Descartes. The book describes the scientific method Francis Bacon would soon champion—to start with observation and induction, being cautious about conclusions and wary of the swaying power of opinion. As al-Haytham put it,
[We should begin] our investigation with an inspection of the things that exist and a survey of the conditions of visible objects. We should distinguish the properties of particulars, and gather by induction what pertains to the eye when vision occurs and what is found in the manner of sensation to be uniform, unchanging, manifest and not subject to doubt. After which we should ascend in our enquiry and reasoning, gradually and orderly, criticizing premises and exercising caution in regard to conclusions—our aim in all that we make subject to inspection and review being to employ justice, not to follow prejudice, and to take care in all that we judge and criticize that we seek the truth and not be swayed by opinion.
But by the time al-Haytham was read by the great minds of Western science, Muslim freedom of inquiry had long since been sacrificed, and Islamic science was no more. British nuclear physicist and Iraqi scholar Jim al-Khalili, who has written extensively about early Islamic science, notes,
There were very few . . . Christian scholars whose achievements could rival their Muslim counterparts until the end of the fifteenth century and the arrival of Renaissance geniuses such as Leonardo da Vinci. By that time, European universities would have contained the Latin translations of the works of all the giants of Islam, such as Ibn Sīna, Ibn al-Haytham, Ibn Rushd, al-Rāzi, al-Khwārizmi and many others. In medicine in particular, translations of Arabic books continued to be studied and printed well into the eighteenth century.
Among the European scholars influenced by their Islamic counterparts before them were Roger Bacon, whose work on lenses relied heavily on his study of Ibn al-Haytham’s Optics, and Leonardo of Pisa (Fibonacci), who introduced algebra and the Arabic numeral characters after being strongly influenced by the work of al-Khwārizmi. Some historians have even argued that the great German astronomer Johannes Kepler may have been inspired to develop his groundbreaking work on elliptical orbits after studying the work of the twelfth-century Andalusian astronomer al-Bitrūji (Alpetragius), who had tried and failed to modify the Ptolemaic model.
But at the very moment Protestantism and the practitioners of the new science were blossoming in Italy, Germany, France, and England, and beginning to draw on the works of their Muslim counterparts, science was shutting down in the Islamic world.
The first reason was politics. A conservative, literalist scientist-theologian named al-Ghazāli, who is influential in Muslim thinking to this day, wrote a critique of Muslim scientists, or Mu’tazilites, called The Incoherence of the Philosophers, in which he attacked their assimilation of the ideas of Aristotle and the concept of a natural causality of things. Writing of fire burning cotton, he said,
The one who enacts the burning by creating blackness in the cotton, [causing] separation in its parts, and making it cinder or ashes is God, either through the mediation of His angels or without mediation. As for fire, which is inanimate, it has no action. For what proof is there that it is the agent? They have no proof other than observing the occurrence of the burning at the [juncture of] only contact with the fire. Observation, however, [only] shows the occurrence [of burning] at [the time of the contact with the fire], but does not show the occurrence [of burning] by [the fire] and that there is no other cause for it.
They should stick closer to the text of the Quran, he argued. Be more “authentic.” The cause of things was not nature, but God.
Those who followed al-Ghazāli adopted the same literalist view as Christian fundamentalists do today: the only cause of anything was God, and the texts of the old books, in this case not the Bible but the Quran and the Hadīth (the recorded conversations of the Prophet Muhammad), gave Muslims everything they would ever need to know about their faith, and so the sort of philosophical debate and reasoning practiced by the Mu’tazilites was not only unnecessary—it was un-Islamic. As for science, what was the point? If the cause of everything was God, God was the only answer.
This fundamentalist interpretation led to many of the antiscience, anti-Western beliefs that have held back progress in more fundamentalist Muslim countries to this day. “The innate religious conservatism of the school of thought that grew around [al-Ghazāli’s] work inflicted lasting damage on the spirit of rationalism and marked a turning point in Islamic philosophy,” argues Al-Khalili.
But the second reason was perhaps even more powerful: the Islamic world’s failure to do what the Europeans, and particularly the followers of Martin Luther, were doing: adopt the printing press, a new technology that was making knowledge much more widely available. While devout Muslim scholars were painstakingly hand-copying holy books with artistic fealty, Lutherans were printing Bibles by the thousands and putting knowledge in the hands of the people to judge for themselves.
The DNA of Western Thought
Each arm of the double helix of Western Christianity—Roman Catholicism and the emerging Protestantism—embodied the two distinct worldviews of the authoritarian and the antiauthoritarian: that rules, methods, and laws were either proscribed from on high or built up by individuals in consensus.
These two views had always been present, but they were amplified in 1517, when Martin Luther posted his Ninety-Five Theses challenging church authorities to debate principles that seemed defensible only by virtue of the church’s authority over its subjects. In Luther’s view, the church had become corrupt, telling people they could buy their way into heaven by purchasing “indulgences,” the proceeds of which the church used to finance building St. Peter’s Basilica in Rome. “Why does not the pope, whose wealth is today greater than the wealth of the richest Crassus [a legendarily greedy first-century Roman businessman],” Luther asked, “build this one basilica of St. Peter with his own money