BookBlog |
|
Adina Levin's weblog.
Mostly for conversation about books I've been reading. Other stuff too.
Where to Find Me RSS Feed Books to Read Next: The Self-Made Tapestry: Pattern Formation in Nature The Symbolic Species: The Co-Evolution of Language and the Brain A Mediterranean Society Small Worlds To Do List
Frequently browsed blogs Archives |
Sunday, September 29, 2002
The editorial argues that the US should invest aggressively in new energy sources in order to free ourselves of dependency on Middle East oil. This is no radical environmentalist pamphlet or obscure foreign policy white paper. The idea has become mainstream. Perhaps it will happen in the forseeable future (though clearly not in the short term.) The death of artificial life
I recently read Steven Levy's book on Artificial Life. I enjoyed the book very much, since the a-life theme weaves together many of the threads of research into complex adaptive systems, and is a useful way of thinking about the relationship between the various topics. Levy also tells a human story of the scientific pursuit of artificial life, the tale of a motley crew of eccentric scientists, pursuing their work at the margins of the scientific mainstream, who join together to create a rich new area for exploration. The book was written in 1992; ten years later, the results of the pursuit of a-life have been decidedly mixed. Despite substantial scientific progress, the more ambitious ideas of artificial life seem to have retreated to the domain of philosophy. And as a scientific field, the study of artificial life seems to have returned to the margins. The topic is fascinating, and the progress seems real -- why the retreat? One way to look at progress and stasis in the field is to consider how scientists filled in the gaps of von Neumann's original thesis. The brilliant pioneer of computer science, in Levy's words, "realized that biology offered the most powerful information processing sytem available by far and that its emulation would be the key to powerful artificial systems." Considering reproduction the diagnostic aspect of life, von Neumann proposed a thought experiment describing a self-reproducing automaton. The automaton was a mechanical creature which floated in a pond that happened to be chock full of parts like the parts from which the creature was composed. The creature had a sensing apparatus to detect the parts, and a robot arm to select, cut, and combine parts. The creature read binary instructions from a mechanical tape, duplicated the instructions, and fed the instructions to the robot arm, which assembled new copies of the creature from the parts floating in the pond. The imaginary system implemented two key aspects of biological life: * a genotype encoding the design for the creature, with the ability to replicate its own instructions (like DNA) * a phenotype implementing the design, with the ability to replicate new creatures (like biological reproduction) The thought experiment is even cleverer than it seems -- von Neumann described the model in the 1940s, several years before the discovery of DNA! In the years since von Neumann's thought experiment, scientists have conceived numerous simulations that implement aspects of living systems that were not included in the original model: * Incremental growth. The von Neumann creature assembled copies of itself, using macroscopic cutting and fusing actions, guided by a complex mechanical plan. Later scientists developed construction models that work more like the way nature builds things; by growth rather than assembly. Algorithms called L-systems, after their inventor, biologist Astrid Lindenmeyer, create elaborate patterns by the repeated application of very simple rules. With modification of their parameters, these L-systems generate patterns that look remarkably like numerous species of plants and seashells. (There is a series of wonderful-looking books describing applications of the algorithms). * Evolution. Von Neumann's creature knows how to find parts and put together more creatures, but it has no ability to produce creatures that are different from itself. If the pond gradually dried up, the system come to a halt; it would not evolve new creatures that could walk instead of paddle. John Holland, the pioneering scientist based at the University of Michigan, invented a family of algorithms that simulate evolution. Instead of copying the plan for a new creature one for one, the genetic algorithm simulates the effect of sexual reproduction by occasionally mutating a creature's instruction set and regularly swapping parts of the instruction sets of two creatures. One useful insight from the execution of genetic algorithm simulations is that recombination proves to be a more powerful technique for generating useful adaptation than mutation. * Predators and natural selection. In von Neumann's world, creatures will keep assembling other creatures until the pond runs out of parts. Genetic algorithms introduce selection pressure; creatures that meet some sort of externally imposed criterion get to live longer and have more occasions to reproduce. Computer scientist Danny Hillis used genetic algorithms to evolve computer programs that solved searching problems. When Hillis introduced predators in the form of test programs that weeded out weak algorithms, the selection process generated stronger results. Genetic algorithms have proven to be highly useful for solving technical problems. They are used to solve optimization problems and model evolutionary behavior in fields of economics, finance, operations, ecology, and other areas. Genetic algorithms have been used to synthesize computer programs that solve some computing problems as well as humans can. * Increasingly complex structure. Evolution in nature has generated increasingly complex organisms. Genetic algorithms simulate part of the process of increasing complexity. Because the recombination process generates new instruction sets by swapping of large chunks of old instruction sets, the force of selection necessarily operates on modules of instructions, rather than individual instructions (see Holland's book, Hidden Order, for a good explanation of how this works). * Self-guided motion. Von Neumann's creatures were able to paddle about and find components; how this happens is left up the the imagination of the reader -- it's a thought experiment, after all. Rodney Brooks' robot group at the MIT AI lab has created simple robots, modeled after the behavior of insects, which avoid obstacles and find things. Instead of using the top-heavy techniques of early AI, in which the robot needed to build a conceptual model of the appearance of the world before it could move, the Brooks group robots obey simple rules like moving forward, and turning if it meets an obstacle. * Complex behavior. Living systems are complex, a mathematical term of art for systems that are composed of simple parts whose behavior as a group defies simple explanation (concise definition lifted from Gary Flake). Von Neumann pioneered the development of cellular automata, a class of computing systems that can generate complex behavior. John Conway's Game of Life implemented a cellular automaton that proved to be able to generate self-replicating behavior (apparently after the Levy book was published), and, in fact, was able to act as a general-purpose computer (Flake's chapter on this topic is excellent). Cellular automata can be used to simulate many of the complex, lifelike behaviors described below. * Group behavior. Each von Neumann creature assembles new creatures on its own, oblivious to its peers. Later scientists have devised methods of ways of simulating group behavior: Craig Reynolds simulated bird flocking behavior, each artificial bird following simple rules to avoid collisions and maintain a clear line of sight. Similarly, a group of scientists at the Free University in Brussels simulated the collective foraging behavior of social insects like ants and bees. If a creature finds food, it releases pheremone on the trail; other creatures wandering randomly will tend to follow pheremone trails and find the food. These behaviors are not mandated by a leader or control program, they emerge naturally, as a result of each creature obeying a simple set. of rules. Like genetic algorithms, simulations of social insects have proven very useful at solving optimization problems, in domains such as routing and scheduling. For example scientists Erik Bonabeau and Marco Dorigo used ant algorithms to solve the classic travelling salesman program. * Competition and co-operation. Robert Axelrod simulated "game theory" contests, in which players employed different strategies for co-operation and competition with other players. Axelrod set populations of players using different algorithms to play against each other for long periods of time; players with winning algorithms survived and multiplied, while losing species died out. In these simulations, co-operative algorithms tend to predominate in most circumstances. * Ecosystems. The von Neumann world starts with a single pond creature, which creates a world full of copies of itself. Simulators Chris Langton, Steen Rasmussen and Tom Ray evolved worlds containing whole ecosystems worth of simulated creatures. The richest environment is Tom Ray's Tierra. A descendant of "core wars," a hobbyist game written in assembly language, the Tierra universe evolved parasites, viruses, simbionts, mimics, evolutionary arms races -- an artificial ecosystem full of interations that mimic the dynamics of natural systems. (Tierra is actually written in C, but emulates the computer core environment. In the metaphor of the simulation, CPU time serves as the "energy" resource and memory is the "material" resource for the ecosystem. Avida, a newer variant on Tierra, is maintained by a group at CalTech). * Extinction. Von Neumann's creatures will presumably replicate until they run out of components, and then all die off together. The multi-species Tierra world and other evolutionary simulations provide a more complex and realistic model of population extinction. Individual species are frequently driven extinct by environmental pressures. Over a long period of time, there are a few large cascades of extinctions, and many extinctions of individual species or clusters of species. Extinctions can be simulated using the same algorithms that describe avalanches; any given pebble rolling down a steep hill might cause a large or small avalanche; over a long period of time, there will be many small avalances and a few catastrophic ones. * Co-evolution. Ecosystems are composed of multiple organisms that evolve in concert with each other and with changes in the environment. Stuart Kauffman at the Santa Fe institute created models that simulate the evolutionary interactions between multiple creatures and their environment. Running the simulation replicates several attributes of evolution as it is found in the historical record. Early in an evolutionary scenario, when species have just started to adapt to the environment, there is explosion of diversity. A small change in an organism can lead to a great increase in fitness. Later on, when species become more better adapted to the environment, evolution is more likely to proceed in small, incremental steps. (see pages 192ff in Kauffman's At Home in the Universe for an explanation.) * Cell differentiation. One of the great mysteries of evolution is the emergence of multi-celled organisms, which grow from a single cell. Levy's book writes about several scientists who have proposed models of cell differentiation. However, these seem less compelling than the other models in the book. Stuart Kauffman developed models that simulate a key property of cell differentiation -- the generation of only a few basic cell types, out of a genetic code with the potential to express a huge variety of patterns. Kaufman's model consists of a network in which eac node is influenced by other nodes. If each gene affects only a few other genes, the number of "states" encoded by gene expression will be proportional to the square root of the number of genes. There are several reasons that this model is somewhat unsatisfying. First, unlike other models discussed in the book, this simulates a numerical result rather than a behavior. Many other simulations could create the same numerical result! Second, the empirical relationship between number of genes and number of cell types seems rather loose -- there is even a dispute about the number of genes in the human genome! Third, there is no evidence of a mechanism connecting epistatic coupling and the number of cell types. John Holland proposed an "Echo" agent system to model differentiation (not discussed in the Levy book). This model is less elegant than other emergent systems models, which generate complexity from simple rules; it starts pre-configured with multiple, high-level assumptions. Also, Tom Ray claims to have made progress at modeling differentiation with the Tierra simulation. This is not covered in Levy's book, but is on my reading list. There are several topics, not covered in Levy's book, where progress seems to have been made in the last decade. I found resources for these on the internet, but have not yet read them. * Metabolism. The Von Neumann creature assembles replicas of itself out of parts. Real living creatures extract and synthesize chemical elements from complex raw materials. There has apparently been substantial progress in modelling metabolism in the last decade; using detailed models gleaned from biochemical research. * Immune system. Holland's string-matching models seems well-suited to simulating the behavior of the immune system. In the last decade, work has been published on this topic, which I have not yet read. * Healing and self-repair. Work in this area is being conducted by IBM and the military, among other parties interested in robust systems. I have not seen evidence of effective work in this area, though I have not searched extensively. * Life cycle. The von Neumann model would come to a halt with the pond strip-mined of the raw materials for life, littered with the corpses of dead creatures. By contrast, when organisms in nature die, their bodies feed a whole food chain of scavengers and micro-organisms; the materials of a dead organism serve as nutrients for new generations of living things. There have been recent efforts to model ecological food chains using network models; I haven't found a strong example of this yet. Von Neumann's original thought experiment proposed an automaton which would replicate itself using a factory-like assembly process, independent of its peers and its environment. In subsequent decades, researchers have made tremendous progress at creating beautiful and useful models of many more elements of living systems, including growth, self-replication, evolution, social behavior, and ecosystem interactions. These simulations express several key insights about the nature of living systems. * bottom up, not top down. Complex structures grow out of simple components following simple steps. * systems, not individuals. Living systems are composed of networks of interacting organisms, rather than individual organisms in an inert background. * layered architecture. Living and lifelike systems express different behavior at different scales of time and space. On different scales, living systems change based on algorithms for growth, for learning, and for evolution. Many "artificial life" experiments have helped to provide a greater understanding of the components of living systems, and these simulations have found useful applications in a wide range of fields. However, there has been little progress at evolving more sophisticated, life-like systems that contain many of these aspects at the same time. A key theme of the Levy book is the question of whether "artificial life" simulations can actually be alive. At the end of the book, Levy opend the scope to speculations about the "strong claim" of artificial life. Proponents of a-life, like proponents of artificial intelligence, argue that "the real thing" is just around the corner -- if it is not a property of Tierra and the MIT insect robots already! For example, John Conway, the mathematics professor who developed the Game of Life, believed that if the Game was left to run with enough space and time, real life would eventually evolve. "Genuinely living, whatever reasonable definition you care to give to it. Evolving, reproducing, squabbling over territory. Getting cleverer and cleverer. Writing learned PhD theses. On a large enough board, here is no doubt in my mind that this sort of thing would happen."(Levy, p. 58)That doesn't seem imminent, notwithstanding Ray Kurzweil's opinions that we are about to be supplanted by our mechanical betters. Nevertheless, it is interesting to consider the point at which simulations might become life. There are a variety of cases that test the borders between life and non-life. Does life require chemistry based on carbon and water? That's the easiest of the border cases -- it seems unlikely. Does a living thing need a body? Is a prion a living thing? A self-replicating computer program? Do we consider a brain-dead human whose lungs are operated by a respirator to be alive? When is a fetus considered to be alive? At the border, however, these definitions fall into the domain of philosophy and ethics, not science. Since the creation of artificial life, in all of its multidimensional richness, has generated little scientific progress, practitioners over the last decade have tended to focus on specific application domains, which continue to advance, or have shifted their focus to other fields. *Cellular automata have become useful tools in the modeling of epidemics, ecosystems, cities, forest fires, and other systems composed of things that spread and transform. * Genetic algorithms have found a wide variety of practical applications, creating a market for software and services based on these simulation techniques. * The simulation of plant and animal forms has morphed into the computer graphics field, providing techniques to simulate the appearance of complex living and nonliving things. * The software for the Sojourner robot that expored Mars in 1997 included concepts developed by Rodney Brooks' team at MIT; there are numerous scientific and industrial applications for the insect-like robots. * John Conway put down the Game and returned to his work as a mathematician, focusing on crystal lattice structure. * Tom Ray left to the silicon test tubes of Tierra, and went to the University of Oklahoma to study newly-assembled genome databases for insight into gene evolution and human cognition. The latest developments in computational biology have generated vast data sets that seem more interesting than an artificial world of assembly language parasites. While the applications of biology to computing and computing to biology are booming these days, the synthesis of life does not seem to be the most fruitful line of scientific investigation. Will scientists ever evolve life, in a computer or a test tube? Maybe. It seems possible to me. But even if artificial creatures never write their PhD thesis, at the very least, artificial life will serve the purpose of medieval alchemy. In the pursuit of the philosophers stone early experimenters learned the properties of chemicals and techniques for chemistry, even though they never did found the elixir of eternal life. Thursday, September 26, 2002
Offering a full line of enlightenment(TM) products
From the schedule of a new Yoga studio in the neighborhood: * Yoga lifestyle clothing by Puma * Pure Ayurvedic Skincare developed by Christy Turlington and Partners * Herbal Products to awaken your Yoga ..... in other words, clothes, makeup, and perfume to help everyone else recognize the state of your inner enlightened being. Wednesday, September 25, 2002
What Went Wrong with What Went Wrong
Based on a recommendation from a blog reader, I picked up "What Went Wrong: Western Impact and Middle Eastern Response" by Bernard Lewis. Given the mixed Amazon reviews, I borrowed the book from the library. The obvious criticisms of the book's style are correct -- What Went Wrong is a collection of transcribed lectures, hastily taken to print after September 11th. The essays are not edited together to support a thesis, and they do not provide a satisfying answer the question in the book's title. Even so, one might expect that lectures given by one of the world's leading experts in Middle Eastern history might contain substantive information based on primary source research, combined with insightful interpretations and a powerful, implicit argument driven by the scholar's point of view, developed through decades of thought on the topic. Such a book would be worth reading, though it would require more work by the reader to assemble the thesis by means of marginal notes. The book has interesting facts and stories. But Lewis' interpretations are badly inadequate, even from the perspective of someone with a sketchy understanding of Muslim history. The subject of the book is the response of the "Middle East" to increasingly evident Western economic and military superiority in modern times. Lewis is an expert on the Ottoman empire, and the book focuses primarily on the Ottoman Turks, secondarily on Iran, and very little on Arab regions (not at all on other Muslim countries which are out of the book's scope). After several painful defeats in the late 17th century to European armies, Ottoman rulers initiated a series of campaigns to study and integrate Western military, economic, and technological advances. The trouble is that Lewis seems to take for granted the flaws in Ottoman culture that he purports to explain. Lewis reports that initiative to learn from Europeans was a traumatic change. "For Muslims, first in Turkey and later elsewhere, this brought a shocking new idea that one might learn from the previously despised infidel." The Ottoman rulers turned to the Ulema, the masters of Islamic law, and requested an exemption from the traditional prohibition against accepting infidel teachers. Yet the intellectual insularity shown by the Ottoman empire was not typical of earlier Islamic regimes, which embraced and integrated external cultural influences and non-Muslim expertise. Baghdad, the capital city of the Abbasid dynasty, was laid out by a Jewish mathematician and a Persian astronomer. Al-Khwarizmi, the Muslim mathematician, explained the Indian number system in Arabic, and made innovative contributions to algebra. Abd al-Rachman III, the ruler of Muslim Spain at the height of its power and cultural influence, had a Jewish vizier, Hasdai ibn Shaprut. Lewis explains the Ottoman ignorance of Western ways as an outcome of Muslim prohibitions against traveling and settling in foreign lands. This geographical insularity also was not typical of earlier Muslim regimes. In the medieval era, the Muslim world was a key link in a world system of trade that linked Europe and Asia. Muslim merchants spent their lives in caravans and ships; there were longstanding Muslim settlements in Southeast Asia and China. The interesting question is not why the belated efforts of the Ottoman empire to adopt infidel knowledge failed. With its underlying attitudes toward "foreign influence" it does not seem so surprising that these efforts were too little, too late. The question is why the Ottoman empire was so much more insular and narrow-minded than the Muslim regimes that came before it. Lewis does mention the decline in Muslim science since medieval times. In the medieval era, Muslim scientists sought out Greek, Indian, and Persian knowledge, and made innovative contributions to mathematics, astronomy, and medicine. By the Ottoman period, Muslim scientists were no longer seeking new sources and adding to the world's store of knowledge, "they had their own science, handed down by great scientists of the past." What happened to the Muslim intellectual tradition in the mean time that destroyed its ability to learn and innovate? Lewis writes that Ottoman efforts to jumpstart the economy by importing factories failed to take root. But he includes no evidence or analysis of underlying economic structures that might have inhibited or fostered economic progress. Two points of comparison. Throughout the medieval era, the Muslim world played a major role in international trade. In the 16th century and later, European ships discovered alternate sea routes to the Far East, and established permanent colonies, cutting out the Muslim segment of the trade route. In 1568, the Ottomans drew up a plan to dig a canal through Suez, to render the Red Sea route competitive again. The following year, they started to dig a canal between the Don and the Volga rivers, to improve the northern trade route. But these plans were abandoned, in favor of head-on war with Russia and Vienna. Why did the Ottoman military initiatives supersede economic ones; did they miss the connection between money and power, or did they believe that territorial conquest would serve them better? In contemporary era, the Arab regions were graced with oil wealth. They imported unskilled Chinese laborers to build oil platforms and refineries. The Chinese workers learned the technology, saved their money, and within a generation had developed world-leading businesses in construction and transportation logistics. Why didn't Arabs take advantage of their privilege and money to move up the value chain and dominate the worldwide oil, chemical, and shipping industries? One might attribute Middle Eastern economic stagnation to flaws in the Muslim legal and financial systems. Lewis doesn't make this argument, but he does make much of the fact that concept idea of secular law comes from the Christian world, where a separation between church and state was needed to keep chronic religious wars from wrecking society. Lewis explains that European colonial and post-colonial regimes imposed systems of secular, Western law, which were sometimes adopted and often resisted by Middle Easterners. Anti-Western Muslim governments throw off the imported systems, and return to the Sharia, the traditional Muslim law code. Contemporary Sharia systems in places like Iran and Afghanistan are often mocked for being medieval and backward, legislating repression of women and brutal corporal punshment (no, I'm not in favor of the Texas death penalty, either). But there is no empirical reason that a system of Muslim jurisprudence needs to be backward. After all, European laws once featured trial by ordeal, and prevented women from owning property. A living tradition of Muslim law might be able to adapt to current economic and social conditions. How did the Sharia change from a system that had once reflected the standards of justice of its time to one that insisted on avoiding change? Lewis writes that Western ideas of equal rights and democracy, which underlie Western legal systems, likewise caught on slowly in the Middle East, and were often imposed by outsiders. Colonial and Western-dominated post-colonial regimes insisted on full rights for non-Muslims, and the ending of slavery (though they ignored restrictions on women). Ideas of liberty were sometimes used by internal reformers, but were often resisted as foreign grafts. But there is no logical reason that Islam itself could not make these changes -- even without a secular system. Islam is based on ideals of equality and justice -- why could these ideas not be extended to enfranchise women, free slaves, and institutionalize the rights of non-Muslims, as they were practiced in the most tolerant Islamic societies. Likewise, there is a Muslim tradition of consultative government. Why has this not been developed into a system of government that takes into account the voices and needs of different sectors of society. Lewis' analysis of the failure of the Middle East to adopt Western technology is weak and superficial. Lewis provides some interesting primary-source documentation about the slow adoption of modern clocks and calendars into Ottoman administration. The resistance to modern timekeeping is illustrated with anecdotes of the leisurely pace of life, even today, in Middle Eastern countries. But Lewis doesn't ask the interesting questions about why the technology of time was ignored. In Western society, technologies of time were adopted in government and business administration, industrial production, and transportation. The Ottoman empire had a fairly advanced administrative system. What was missing in Ottoman government and economic institutions that they did not see the benefit of these technologies, or were unable to implement them? Norvell De Atkine, the US military trainer, argues that contemporary Middle Eastern armies failed to successfully assimilate modern weapons, not because of lack of technology, but because of flaws in organizational culture. Middle Eastern governments brought in Western trainers and technology, but the troops were unable to use and maintain the systems because of their aversion to sharing information. An officer trained in the use of a weapons system would not share that knowledge with rest of his men, because sharing knowledge would reduce his power. Did Ottoman armies and administrations have these problems sharing information -- is this what made it diffiicult to embrace new technology and methods? In the early days of Muslim conquest, were armies this bad at communicating, and successful nevertheless? Lewis doesn't say. Some of Lewis' explanations about the Middle East's failure to Westernize are simply laughable. Lewis makes much out of the reluctance of Middle Easterners to appreciate European classical music. Lewis attributes Middle Eastern indifference to European classical music to a general aversion to foreign influence, and in particular to a dislike of polyphonic technique, which uses the same organizational genius as Western team sports, parliamentary government, and corporate structures. Lewis doesn't notice the many and substantial foreign influences on Middle Eastern music, which come from the East instead of the West. Muslim classical musical styles were heavily influenced by Indian and pre-Muslim Persian styles. Popular Middle Eastern music is full of influences from Central and Eastern Europe. Today, music from India is extremely popular in the Middle East. Muslims do like foreign music, they just happen to find eastern styles more congenial than western styles! By contrast, Lewis talks approvingly of the adoption of European architectural styles. He does not mention that medieval Muslim empires created their distinctive architectural styles from the elements of existing buildings. In Eastern regions of Muslim dominance, mosques were converted from Byzantine churches. In medieval Spain, Muslim took the columns, literally and figuratively, from the ruins of Roman buildings. Muslim architecture always incorporated foreign influences; this was the rule, not the exception. Throughout the book Lewis describes the tensions between modernizers, who wished to replace the traditions of Muslim society with European imports, and traditionalists, who wished to recover a lost world of cultural purity. Lewis himself seems to agree with the assumptions underlying this debate, and he takes the side of the modernizers. Lewis seems to embrace the assumption that a strong civilization builds its own culture out of native materials; but a weak civilization needs to adapt to cultural norms of the stronger power. Lewis doesn't consider that a strong civilization is one which is able to embrace, absorb and transform diverse influences. In other words, Lewis makes the same mistake as the subjects of his historical inquiry. Here's what I take away from the book, based on Lewis' evidence and other reading. The decline in Muslim civilization occured long before it the evident decline of the Ottoman empire. The Ottoman empire was militarily powerful in its day, and wealthy at its prime, but it lacked the cultural flexibility required to innovate and adjust to change. But why was the Ottoman empire so insular and inflexible? Lewis describes the phenomenon, but doesn't explain it. By the way, I haven't read Said's Orientalism (yet), which criticizes Bernard Lewis in particular, and Western scholarship in general, for colonalist and racist stereotypes of the inferiority of Muslim cultures. The problem with What Went Wrong isn't that Lewis' criticisms are biased, it is that they are shallow; they don't explain very real flaws of Middle Eastern societies in modern times, which are flaws even with respect to the greatest historical achievements of Muslim civilization. Tuesday, September 24, 2002
Traditional Muslim Blessing
"May there always be coffee at your house," wishing ones friends prosperity and the joy of hospitality. From a web page on Arab contributions to society. The Ornament of the World: How Muslims, Jews, and Christians Created a Culture of Tolerance in Medieval Spain
The Ornament of the World, by Maria Menocal, is a fascinating but flawed book about Muslim culture in medieval Spain. The exciting parts of the book are the stories of cultural influence among Muslims, Jews, and Christians. These cultural influences shed light on some fundamental chapters in history that are told often but explained poorly. * You may have learned in European history class that medieval Arab culture preserved Greco-Roman classical knowledge during the Europe's dark ages. Menocal's book tells the story how classical works of science and philosophy, preserved in Arabic, were transmitted to Christian Europe. In the 8th-10th centuries, most of the Iberian peninsula was ruled by the Umayyad dynasty, with Cordoba as its capital. The Umayyad rulers, in competition with the Abbassid Caliphate based in Baghdad, established Cordoba as a center of higher learning, building an extensive library and funding leading scholars. In the 11th century, the Umayyad government fell, the Iberian peninsula became divided into dozens of warring city-states, and Christian rulers from the North of Spain gradually increased their domains. The Christian-controlled areas continued to be heavily influence by Muslim culture. Alfonso IV of Castile, ruler of the Taifa of Toledo, wanted to publicize this learning within Christian Europe, and funded the translation process. Jewish and Arab scholars read texts in Arabic, and recited them out loud in Castilian. Christian scholars listened to the spoken Castilian and wrote in Latin. * If you studied European literature, you probably have some recollection of the troubadours of Provence, who pioneered the poetry of courtly romance. In the 11th to13 centuries, a seemingly remote region in the south of today's France, heretofore known for bloody turf wars between rival Frankish feudal lords, suddenly produced a flowering musical and literary culture. Where did this surge of civilization come from? The region of Provence is located on the Northeast side of the Pyrenees. The constant warfare among the citystates of the Iberian peninsula offered attractive opportunities for free-lance Frankish knights, who crossed the mountains to seek their fortune, and helped to conquer Muslim cities. These knights were captivated by the music and poetry of Andalusian culture, and returned to Provence, bringing with them groups of professional singers of Arabic songs, traditions of stylized lyric poetry, and romantic conceptions of love. * If you have a basic background in Jewish history and philosophy, you may recall the Kuzari, medieval work by Judah Halevi. The frame-story of the Kuzari is the correspondence between a Jewish scholar and the King of a central Asian tribe called the Khazars, who requested an explanation of various beliefs and philosophies; in order to introduce the best tradition to his people. The Kuzari includes logical "proofs" of the existence of God, and arguments for the superiority of revealed religions truth to philosophies based on reason. Menocal tells more of the story. The correspondence with the Khazars was conducted several generations earlier, in the 10th century, by Hasdai ibn Shaprut, the foreign minister to the Umayyad caliph Abd al-Rachman III. That correspondence compared Judaism with Christianity and Islam. Halevi lived and worked two hundred years later, and was a student of Moses Ibn Eza, philologist, poet, and fan of the Andalusian culture, in a time when all three monotheistic faiths struggled with the implications of Greek philosophy. Halevi spent most of his career as a peripatic scholar and poet in Jewish intellectual circle. Later in his life, he had a change of heart, and advocated a return to Judaism cleansed of the corruptions of secular life and philosophical influences. He wrote the Kuzari arguing that philosophy is incompatible with faith, wrote beautiful poems about Israel in exile, yearning for God, and he died on a pilgrimage to crusader-controled Jerusalem. Menocal writes in a romantic and nostalgic style that derives in part from her subjects own elegaic esthetic, and from her own nostalgia for the world of Andalusia. Sometimes the style works, especially when describing works of architecture built as monuments and memorials. She describes the initial design of the Alhambra palace gardens: "The first gardens built on the red hill by those exiles from Cordoba were, like Abd al-Rahman's palm tree, the echoes and reconstructed memories of a mourned homeland." Sometimes the romantic language is overwrought and awkward, as in these description of the writing of Shmuel Hanagid, the vizier of Grenada, military general, Jewish communal leader and Hebrew poet. "The third poem, to praise the third victory, had flowed most easily of all, and he could now more effortly flex those new muscles that sang of arms and men and God... In that loving and revolutionary embrace by a powerful and supremely self-assured man, Heberew was redefined, and cultivated as a language that could transcend the devotional and theological uses to which it had lately been limited." Particularly irritating is the use of purple prose to cover the lack of information. For example, the author describes the libraries of Cordoba as follows: "The rich web of attitudes about culture, and the intellectual opulence that it signified, is perhaps only suggested by the caliphal library of, by one count, some four hundred thousand volumes, and this at a time when the largest library in Christian Europe probably held no more than 400 manuscripts." An impressive collection of books, to be sure. But who read those books? What classes of society were literate? What role did higher education play in society? What was a typical curriculum? Were the books mostly copies of classical manuscripts, or did they include new scholarship? No answers, just vague sentences such as: "Just as essential to the social and cultural project embedded in those libraries was a series of attitudes about learning of every sort, about the duty to transmit knowledge from one generation to another, about the interplay between the very modes of learning that were known to exist..." The book provides context for a better understanding of the history of Christian, Muslim, and Jewish cultures, sheds light on a fascinating historical period, and whets ones appetite for more information. It is definitely worth reading. Thursday, September 19, 2002
Rice-cookers and self-knowledge
I just burned a pot of rice. Several years ago, I purchased a rice cooker, because I always, invariably, without fail, burn rice on a stove. This morning, I went to cook some rice and realized the rice cooker needed cleaning. So I put rice and water in a pot, heated to boil, turned down the heat, and went off to make a couple of phone calls & emails. And Voila. Fortunately, the kitchen has a heat detector but no smoke detector. We'll see if I've trashed the very nice, gift Calphalon pot. One of the benefits of being an adult is that you know your own strengths and weaknesses, and can compensate with workarounds. Then, every once in a while, you ignore old lessons... Wednesday, September 18, 2002
Back from the road
I'm back from several weeks on the road, visiting friends and family. Bunches of posts are in the queue... Tuesday, September 17, 2002
The Mapmakers
While on the road, I read The Mapmakers, by John Noble Wilford, Pulitzer prize-winning science writer for the New York Times. The book tells the stories of the scientists and explorers who pioneered the techniques and practice of mapmaking. The book explains early ingenious efforts to measure the size and shape of the earth, and the invention of techniques for surveying territory and projecting the sphere of the earth onto paper. Wilford is particularly good at telling tales of pre-20th century adventurers: * the Frenchmen who travelled to Lapland and Peru to figure out how the sphere of the earth is out of true * John Harrison, the watchmaker with working class origins, who built the first clock precise and reliable enough to measure longitude, and fought the aristocratic science establishment that refused to give him credit for the discovery * James Cook and George Vancouver, who added the coasts of the South Pacific and Western North America on European maps, and subtracted the Northwest Passage and the lush, legendary Terra Australis. * The members of the India Survey who infiltrated and mapped Chinese-controlled Tibet in the 1860s while posing as lamas, including Nain Singh, who used a prayer wheel to store slips of paper with compass and distance measurements instead of prayers, paced off distances with rosaries containing 100 beads instead of the traditional 108, and carried a sextant, compass, thermometer and mercury container in a false-bottomed box. The book slows down somewhat with the advent of 20th century team science, but still tells interesting stories about the use of new technology to map previously inaccessible territory; side-looking radar under clouds in Amazon rain forest, radio echo sounding under the Antarctic ice sheet, seismic mapping under the earth, sonar under the ocean floor, satellites and spacecraft on the moon and Mars. The Mapmakers purports to be world history, but it has a strong European focus. Wilford does include few pages about sophisticated early mapmaking practices in China. But he almost completely ignores Muslim and Indian geography. The book contains just one brief reference to ibn Khaldun, the medieval Muslim traveler and geographer, and nothing on Al Idrisi, who was commissioned by Roger II, the Christian king of Sicily, to update navigational records, and created the famous early atlas called "The Book of Roger." The Mapmakers briefly mentions that one Francis Wilford, a member of India Survey, was a student of ancient Hindu geography. Given early Indian sophistication in astronomy, math, and government administration, one wonders what earlier sources of geographic knowledge he drew on. According to an Indian friend of mine, many early maps were destroyed to keep them out of the hands of British colonial rulers. Wilford writes about the dire level of geographic ignorance of Medieval Europeans, whose maps routinely placed Paradise at the Eastern border of China, without noting that during the same period, there was a longstanding, ongoing system of travel and trade from Arabia through India and Southeast Asia to China (see books by Abu Lughod and KN Chaudhuri, among others), conducted by Arabs, Jews, Indians, and sometimes Chinese. I don't know what sorts of maps were used by these travelling merchants, but they must have used something, because they got from place to place regularly and routinely. Wilford tells the story of mapmaking as a process of technological development and scientific discovery. Readers are left on their own to infer the social contexts of mapmaking from the details of the tales of "exploration": in the 16th-19th centuries, European colonial expansion; in the 20th century, the hunt for oil and gas resources, and the advances of military missiles, and submarines, and spy satellites. The sociopolitical history of mapmaking is a different book than the one Wilford wrote; that would also be and interesting story to read. Tuesday, September 03, 2002
The smallest houseguest
A very little lizard scampered into my house one day when I opened the door to the deck. If it can feed itself on things it finds indoors, it's doing me a favor, so I haven't chased it away. It looks brown on the hardwood molding, mottled on the berber carpet, and albino in the bathtub. I shoo it from the bathtub if I want bath privileges. |