My earliest memory of that experience comes from reading Alfred Zimmern's classic The Greek Commonwealth. Zimmern took for granted that the ancient Greeks lived in the same world as the ancient Hebrews, and that you might gain insight into early Greek literature by reading the Hebrew prophets, or vice versa. I had been raised in a religious community that read the Bible in religion classes and the Greeks in history classes -- two different worlds. How strange it was to tear down that wall and see them both inhabiting the same planet.
The books I'm going to describe below are boundary-breaking in the same way. None of them is as well-known as it deserves to be, and all provide the intellectual rush that comes from linking previously separated parts of your brain.
The Ornament of the World by Maria Rosa Menocal recreates the vanished world of al Andalus, the Muslim empire that once dominated what is now Spain. Menocal turns upside down our notions of medieval and modern. Medieval al Andalus was a place of tolerance and high civilization in which Jewish and Christian culture flourished alongside Islam. Ultimately, it was replaced by the modern nation-state of Spain, which protected its fragile national identity by forcing Jews and Muslims to convert to Christianity, and then set up the Inquisition to enforce those suspect conversions. In Menocal's book it is the medieval world that is capable of handling contradiction and living with ambiguity, while the modern world arrives with an oppressive and sterile uniformity.
The boundary this book breaks is the one between Christendom and the Dar al Islam. One major theme of the book is how the high civilization of al Andalus seeded the rise of European culture. Greek writers that had been forgotten in the Latin west were translated into Arabic in Baghdad and survived in the libraries of al Andalus. When Christians began to reconquer parts of Spain, they acquired not only some of these libraries, but also Arabic-speaking Christians and Jews who could re-translate these works into Latin. This is how Thomas Aquinas came to know Aristotle and Fibonacci brought Arabic numerals (and the ever-useful concept of zero) to Europe. It probably is how Dante learned the story of Mohammed's trip through Heaven and Hell, guided by the archangel Gabriel.
Entire languages were transformed in al Andalus. Jewish poets like Halevi followed the model of Arabic and recreated Hebrew as a language of man and not just of God, of love songs as well as prayers. Under similar influence, Castilian became the first of the European vernacular languages to usurp the role of Latin in high literature. Immigrants out of al Andalus brought Arabian inventions like the astrolabe that made possible the European age of exploration. They also brought entire forms of literature; Menocal connects the dots between Arabian Nights and The Canterbury Tales and The Decameron. The foundation of Jewish Kabbalah, The Zohar, was written in Castile. Moses Maimonides came from al Andalus, and Spinoza from the Jewish community that emigrated to Amsterdam to escape the Inquisition. Menocal sees the ruins of the Islamic and Jewish communities of al Andalus as the necessary background to understanding the early 17th century Don Quixote.
Isn't it a Cervantes-like delusion to imagine we can read the novel outside its complex and tragic historical setting, a setting that does not have to be detailed in Don Quixote itself precisely because it is the everyday fare of its author and its readers, and which perhaps cannot be detailed on pain of being burned?
The story of al Andalus has its own romantic qualities. It begins with an 8th-century power struggle in the Islamic caliphate, when the Abbasids overthrow and massacre the previous Umayyad dynasty. The last surviving Umayyad escaped to the farthest western arm of the Islamic world, where he overthrew the client government in the Iberian peninsula and began establishing the basis for a rival caliphate. His descendants built Cordoba to be a world capital, a rival of the Abbasids' new city of Baghdad. It was beautiful Cordoba that a Saxon writer of the 10th century described as "the ornament of the world."
The Umayyad dynasty of al Andalus fell in the 11th century and much of Cordoba was destroyed, including the legendary gardens of Madinat al Zahra. Subsequently, the region divides up into rival city-states -- some Muslim, some Christian -- that battle among each other until Spain is united under Catholic rulers. But many of the Catholic city-states had maintained the tolerance established by the Umayyads, and Menocal does not present the Inquisition as inevitable.
The fact that Ferdinand and Isabella did not choose the path of tolerance is seen as an example of the intractability and inevitability of intolerance, especially in the premodern era. But their actions may be far better understood as the failure to make the more difficult decision, to have the courage to cultivate a society that can live with its own flagrant contradictions. They chose instead to go down the modern path, the one defined by an ethic of unity and harmony, and which is largely intolerant of contradictions.
Ultimately, the author leaves us with a question:
Is the strict harmony of our cultural identities a virtue to be valued above others that may come from the accommodation of contradictions?
The Jesus Sutras by Martin Palmer recreates the culture of the Silk Road, where East and West were not sharply divided. Ostensibly the book is about the scriptures produced by the little-known Taoist Christian community before it was wiped out in a 9th-century Chinese purge of foreign religions (which was aimed at Buddhism). But like Marco Polo, Palmer can't resist passing on the good stories he comes across while investigating the Taoist Christians.
Mostly, these stories involve influences that almost everybody else has forgotten. For example: the Silk Road kingdom of Gandhara, where pagan Greek-speaking artists ran into Buddhism while escaping from the Christian oppression of the late Roman Empire. Any first-rate American art museum has one or two examples of Gandharan art if you look for them. They're very striking, because they show Greco-Roman people in traditional Buddhist poses and settings. Oddly enough, this was the beginning of representational Buddhist art. The early Buddhists didn't make statues of Buddha. Instead, they represented him indirectly and abstractly, sometimes as a set of footprints. With no Buddhist models to work from, the Gandharans based their image of Buddha on Apollo. That's why Buddha wears a toga, has a solar halo, is clean-shaven, and has a bump on the top of his head of curly hair.
Palmer makes a more speculative connection between the Virgin Mary and the goddess Quanyin. Oversimplifying greatly, the male Bodhisattva of Compassion Avalokitesvara goes down the Silk Road, runs into the Virgin Mary, and comes back East as Quanyin.
Everybody knows about the Roman Catholics and the Greek Orthodox, but the Thomarist Christians of India are not so well known, so Palmer tells us about them. They trace their origin to the Apostle Thomas, who (according to local legend) was martyred in Madras.
Palmer's story starts with his rediscovery of the ancient Christian monastery of Da Qin in far western China. But Da Qin is just a stone's throw from Lou Guan Ti, so we hear its fascinating legend as well:
Traditionally Lao Zi [more commonly written Lao Tzu] is thought to have been an adviser at the emperor's Court. Famous throughout the country for his wisdom, he eventually grew tired of the corruption he saw at Court. Believing that all of China had become as degraded as the Court, he decided to leave.
The story goes that a watchman, told by the gods to be vigilant for a sage leaving China, built a lookout tower at the Pass to the West. One day he saw a sage riding upon an ox and rushed from his tower to invite him to stay the night. Recognizing that his guest possessed great wisdom that would be lost when he left the country through the Pass, the watchman pressed Lao Zi to write down his philosophy of life. The next morning, legend says, having stayed up all night writing, Lao Zi shook the dust of the kingdom from his feet and departed for the West, never to be seen again. But his book, which became known as the Tao Te Ching, survived and is the foundation of Taoism.
Eventually, Palmer gets around to telling us what's in the sutras of the Taoist Christians. And while that doctrine is interesting in its own right, the real reason to read the book is for all the surrounding stories. You'll never again think of East and West as entirely alien to each other. If Islam and the Mongols hadn't intervened, the Silk Road would have created a mediating culture.
The Shape of Ancient Thought by Thomas McEvilley is a tome, not to be picked up lightly. But it tells the surprising story of the mutual influence between ancient India and ancient Greece. The bird's eye view of that story goes like this: a set of ideas that McEvilley calls the monism complex develops in India sometime before 500 BC. Simplifying enormously, the monism complex revolves around the idea that there is one cause or one set of causes behind everything that happens, and all things partake of one substance. That idea gets taken west by Jains and other missionaries who travel to other lands as a method of overcoming their egos. (In other words, it's really hard to reach enlightenment if you're surrounded by peasants who think you're a holy man, but if you travel to a country where everybody thinks you're weird, you have a better shot.) Some of these folks wind up in what is now the west coast of Turkey, where they inspire the pre-Socratic philosophers like Thales, Anaximander, Empedocles, Parmenides, and the early Pythagorians. Indian mystical ideas were simultaneously influencing Greek mystery cults like the Orphics.
Whether by cause or coincidence, Greece starts its golden age at about the same time as these ideas show up. After 200 years of rapid progress, the monism complex and its associated notions has turned into the logic of Aristotle and the dialectic method of Plato. At that point, it gets re-introduced into India via the Greek-speaking or Greek-influenced Silk Road kingdoms like Bactria and (once again) Gandhara, at which point Greek ideas start to influence the development of both yoga and Buddhism.
That short description does little justice to McEvilley's huge book, which gives an excellent introduction to all sorts of Indian and Greek thought and culture. It is also a treasure-trove of religious and philosophical tidbits. Consider this bizarre practice:
In the stage of Pasupata practice known as the "seeking of dishonor," the devotee was to efface his ego through courting contempt and abuse from his fellow humans by actions deliberately feigned but appearing to be forthrightly despicable. "He who is despised," explains the Pasupata Sutra, "lies happy, free of all attachment."
An unjust act creates bad karma for the perpetrator and good karma for the victim, a process which the seeker of dishonor manipulates like this:
The aspirant is told to behave like a vampire, deceptively and deliberately draining off the good karma of others and secretly transferring his own bad karma to them. While they seem to be mistreating him, he is really mistreating them.
After you've reviewed a number of permutations of ideas (like karma) that you may thought you understood, you'll never look at them the same way again.
If you have any other examples of boundary-breaking books, add them to the comments.