Book Excerpt: Shores of Knowledge

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Bill recently spoke with historian Joyce Appleby on Moyers & Company to discuss her latest book, Shores of Knowledge: New World Discoveries and the Scientific Imagination. The following excerpt is the introduction to the book.


When Christopher Columbus returned from the Western Hemisphere in the spring of 1493, he came with news that would decisively change Europe. No consequence would be more portentous than the conversation his discoveries prompted about the natural world, for he made the subject of nature suddenly interesting with all the odd things he brought home. Sailing back to Spain on the Niña, he packed the little caravel to the gunwales with fantastic objects from the Caribbean islands he visited. Six Taino natives, out of a dozen, survived the return trip, giving vivid proof that people lived in what geographers called the antipodes. Birds from the West Indies survived the trip better than the Tainos. Columbus had plucked flowers even more colorful than the brilliant parrots he found in the tropical rain forests. He showed his sponsors, King Ferdinand and Queen Isabella, a bit of gold that some natives had given him, thinking that it would guarantee funding for subsequent voyages — and he was right.

Over the course of the next three centuries, a succession of amateur investigators laid the foundation for the modern life sciences even though before the end of the fifteenth century, Europeans had been an incurious people. Finding these masses of land filled with mysterious people, unfamiliar plants, weird animals and striking topography produced the kind of shock essential to shaking free of the church’s venerable injunction against asking questions about nature. Men and women in China and Muslim Spain’s Córdoba had demonstrated a much stronger inquisitive spirit. In Europe, isolation and religious disapproval had curtailed curiosity for over a millennium.

Today, plying incessant questions to nature is one of the strongest features of the modern West. The stirring of Europeans’ interest in the physical world began at the end of the fifteenth century with the discovery of two continents lying between them and the Orient. Like most profound cultural changes, there were layers of habits and convictions to work through before Europeans could engage fully with the natural world. They had to break with the church’s prohibition of intrusive questioning about God’s domain — the phenomena of his created universe. The assumption that they already knew everything worth knowing had erected another barrier to the investigative spirit, as well as the predisposition to look backward to biblical or classical times for guidance and knowledge. The designation New World suggests the dimension of their surprise. That the forebears of those in the West, long distinguished for its scientific élan, had to be blindsided before they became inquisitive comes as a surprise. It’s also true, and this is a book about how it happened.

The Catholic Church had succeeded for a thousand years in keeping curiosity in check out of fear of probing questions about cosmic events like eclipses and comets. Such inquiries were deemed vain, a petty challenge to God’s all-encompassing knowledge. Of course the church couldn’t suppress all curiosity, certainly not a child’s endless queries about what and why. But even the spirits of children will be dulled if the answers they hear are always “because God willed it so.” The campaign against curiosity began with Augustine, who lived when Christianity was becoming the dominant religion in Europe.

In its heyday a century before Augustine was born, the Roman Empire stretched from Britain to North Africa and eastward from the Iberian Peninsula to both the Black and Red Seas. Germanic tribes began to make incursions into Rome’s domain in the third century. Emperor Constantine established a new capital on the Bosporus. Then the Empire split permanently into eastern and western parts, with the eastern center of religious life in Constantinople. Constantine, whose mother converted him, legalized Christian worship in 313. As the Eastern Orthodox Church grew in importance, the Western Empire declined. By the time Augustine, born in North Africa, had become a passionate Christian, the Visigoths had sacked Rome.

The accelerating decline of the Roman Empire had a profound effect. The humbling of this great power suggested the ephemeral quality of human endeavors. The replacement of the civility of Roman rule with the utter confusion wrought by the victo-rious Germanic tribes turned men and women’s thoughts to God’s order. Augustine evoked the imagery of the City of God and the City of Man to console his anxious contemporaries. He comforted them by emphasizing the transience of earthly things and hence their unworthiness of a true Christian’s concern.

More relevant to this study, Augustine, now a bishop, condemned curiosity about the material world. He stated unequivocally that “it is not necessary to probe into the nature of things, as was done by the Greeks.” “Nor need we be in alarm,” he elaborated, “lest the Christian should be ignorant of the force and number of the elements — the motion and order and eclipses of the heavenly bodies; the form of the heavens, the species and the nature of animals, plants, stones, fountains, rivers, mountains, about chronology and distances, the signs of coming storms; and a thousand others things which those philosophers either have found out or think they have found out.” “It is enough,” he concluded, “for the Christian to believe that the only cause of all created things… whether heavenly or earthly… is the goodness of the Creator, the one true God.”

At another time such a dogmatic position might not have reverberated through the ages, but the centuries after the fall of Rome were chaotic. The invading Germanic tribes, coming in waves over three centuries, had to build permanent settlements far from their origins, while Romans and their allies dealt with the destruction of their civilization. The church offered a haven from the turmoil. The bar to curiosity entrenched itself as an article of faith. In the ensuing centuries, Europeans pretty much stuck to home, concentrating their intellectual energy on establishing Christian institutions that would withstand doubt, despair and dissent.

Isidore of Seville advised leaving “to one side, like a secret, anything which the authority of the Holy Scriptures has not caused you to learn.” He called curiosity a dangerous presumption leading to heresy. “It embroils the mind,” he said, “in sac-rilegious fables.” Isidore lived in the seventh century, so his strictures might be of little import for people eight centuries later. But that in fact was the problem: Christians were supposed to adhere to a set of beliefs frozen in time.

Bernard of Clairvaux evoked the fall of Adam to castigate curiosity as “the beginning of all sin.” God had punished Adam and Eve severely for it. Men intent on learning the “height of the sky, the breadth of the earth and the depth of the sea” earned the disapproval of the thirteenth-century pope Innocent III as well. Monks were given manuals to help them stifle curiosity, which was thought to arouse inappropriate desires, both intellectual and sensual. Christians might not know everything about the world, but their God did, and that should be sufficient. Everything that existed was subordinate to God’s will; anything that happened had providential implications.

A very powerful and pervasive institution, the church claimed the authority to discriminate between legitimate and illicit knowledge, between permitted and prohibited questions, even between accepted and forbidden methods of acquiring knowledge. After the Reformation, Protestant leaders revived the attack on curiosity in the sixteenth century. John Calvin associated it with the deadliest of deadly sins: pride. King James I of England pointed to Eve for evidence of how curiosity could harm someone.

Europeans were little exposed to the larger world through travel. Religion had stirred crusades to the Holy Lands in the tenth, eleventh and twelfth centuries, but after that, the crusaders’ descendants stayed put. Overland trade with Asia was cut off for decades at a time. Still, there were some venturous souls. Merchants in Genoa and Majorca began visiting the islands off Africa. The Vivaldi brothers of Genoa set sail west to India, but were never heard from again.

When that most celebrated traveler, Marco Polo, returned to Europe in 1294, he landed in a Genoese prison. Fortunately for thousands of future readers, his cell mate happened to be a writer. To him, Polo recounted the details of his Venetian merchant family’s twenty years in the Orient and how his father met Kublai Khan, the grandson of Genghis Kahn. He described their encounters as diplomats and traders at the great Mongol court at Karakorum and the high drama of their escape from their possessive host in a perilous two-year voyage. Most Europeans got their first impression of China, India and Japan from this travel journal.

Henry the Navigator, a Portuguese prince, spent his considerable fortune sending expeditions down the west coast of Africa in the middle decades of the fifteenth century. He was determined to find out what lay south of Cape Bojador at the 24th parallel, which marked the farthest that Europeans had sailed down the west coast of Africa, but he dispatched others there, preferring to stay at home himself.

Henry was fired by the desire to wrest the Canary Islands from Spain and to find a coastal source for the gold and slaves traded in the interior of the African continent. Where he differed from his predecessors was in recognizing the importance of improving navigation. While fighting for Portugal against the Arabs in Morocco, he took stock of what their mariners knew about commercial linkages and the level of their sailing skills. He familiarized himself with Arab mapmaking. Never going to sea himself, Henry was content with gathering around him in his academy at Sagres a cadre of expert navigators, shipwrights, astronomers, pilots and cartographers, both Christian and Jewish. He was mindful of fears that the southern waters were filled with monsters and wrapped in deadly fog, but he calmly stated, “You cannot find a peril so great that the hope of reward will not be greater.” Like Columbus a half century later, ambition fueled his many navigational projects.

The ships that plied the Mediterranean were far too slow and large for oceanic travel. Venturing out in this unknown stretch of the Atlantic demanded new techniques and new equipment, accrued through trial and error. Arab navigators in the southern Mediterranean had introduced triangular sails, fore and aft, called lateen sails. They also added a small foremast, the mizzen, that improved steering. Henry incorporated these Arab inventions into his light, fast caravel, rigged for sailing close to the wind. From his estate perched on the rocky promontory jutting into the Atlantic in the southwest corner of Portugal, he sent pairs of these caravels to chart the winds and waters along the bulge of Africa.

From the 1420s until his death in 1460, Henry’s expeditions got ever larger; they located successful routes and found safe harbors for provisioning. Slowly, after many failed endeavors, they solved the problems of navigation in the South Atlantic. Once they brought back gold and slaves, the voyages became remunerative. Within a century, Africans composed a tenth of the population of Lisbon, a city still underpopulated from the Black Death of the previous century.

Henry died before Bartolomeu Dias rounded the Cape of Good Hope in 1487, but by that time explorations down the coast of Africa had found other royal patrons. When the Portuguese mariners got below the equator, the North Star was no longer in the heavens, which meant that they had to develop new celestial navigation with the Southern Cross, the constellation visible in the Southern Hemisphere almost any time of the year.

Adding to the pressure to find a sea route to the Indies was the fall in 1453 of Constantinople to the Ottoman Turks, who closed off trade with Europe. Bringing in cinnamon, cloves, nutmeg and pepper on overland routes became more costly and more fraught with peril. Going by water to the fabulous islands could cut out the Arab merchants who acted as middlemen. Having discovered the winds that would carry ships around the tip of the continent, Dias opened the way for others to reach the East Indies. A generation of sailors from the ports of Italy and the Iberian Peninsula could now follow where the geographic pioneering of Henry had pointed.

With prospects for great success, the Portuguese king had no compunctions about rejecting appeals for support from a Genoan named Christopher Columbus, who had a different idea about reaching the Indies. Discouraged, Columbus turned to Spain, where Queen Isabella and King Ferdinand had just joined their kingdoms to form a united monarchy in Spain. As rivals of Portugal, they sought a different route to the fabled riches of the Orient and offered to sponsor Columbus’s expedition. Even more important to the devout queen than catching up with the Portuguese was the possibility of extending the realm of Christendom in Asia. Columbus shared this goal. He extracted promises from them to receive 10 percent of all the goods found in the lands. His son wryly noted years later when the family was fighting over what they thought was due their father that the monarchs had probably not expected him to get back alive. But he did, after a seven-month round trip to the Caribbean.

News of the discoveries in the Western Hemisphere arrived when Europeans were still absorbing the philosophy of ancient Greece and Rome. After being cut off from these stores of knowledge and wisdom for a millennium, scholars acquired access to them through the libraries of the Muslims in Córdoba. The rebirth in the term “Renaissance” refers to the flowering of art and literature in response to this recovery of classical texts. After the Turks took Constantinople, many Greek scholars moved to Italy, bringing with them a thorough understanding of the -Greco-Roman writers whose worldly perspective was so different from the spiritual otherworldliness of medieval Europe.

Christians might not know everything about the world, but their God did, and that should be sufficient. Everything that existed was subordinate to God’s will; anything that happened had providential implications. This presented difficulties to Thomas Aquinas and others living in the thirteenth century who were trying to incorporate the newly accessed texts from Aristotle into the Christian tradition, for Aristotle had considered the desire to know a natural one. Aquinas’s solution was to distinguish among possible objects of curiosity on the basis of their contribution to Godliness.

Ancient writings brought in a questioning attitude that startled with its intellectual insouciance. They bristled with inquiries, hypotheses and stratagems for proof. To read them was to reassess what one thought one knew. The freshness of this engagement has to be measured against the medieval obsession with doctrine, form and faithfulness to sacred texts. An appreciation of the Greek and Roman philosophers, like news of the voyages of discovery, moved from the fifteenth-century preserve of classicists to a wider group of educated readers with the publication of translations of the texts.

As secular concerns intruded upon religious ones, a naturalism came to dominate paintings and sculpture. Michelangelo’s famous statue of David comes to mind. Philosophical prose became more direct and vivid. The desire to make the world a better place in which to live led some to ponder which forms of government were the best, an analysis that tended to undermine the awe that all governments had deliberately cultivated, the better to rule.

Greater knowledge of the ancients led to the recognition of how profoundly different in their tastes, mores, assumptions and convictions they were from fifteenth-century Europeans. The divergence of Greek learning from Christian cosmology added to the intellectual turmoil from the discovery of the New World. Slowly — social and intellectual change is always slow — it dawned upon Europeans that their world was a far different one in every measure conceivable. From this conclusion came the even more arresting awareness of change over time, of history itself, not as a narrative of events, but as a depiction of a bygone era that reveals the various ways that different societies have shaped human experience. The past became like a foreign country, but it took a much more thorough examination of it to turn this insight into a meaningful metaphor.

Europeans began studying the recovered works of Ptolemy, the first-century Greek who had collected in one volume all the geographic knowledge that had been acquired in his Greco-Roman world, just as the discovery of the New World was making more salient than ever how little they actually knew about the planet they lived on. With an old text and a new map, they began delving into just those subjects that Augustine had excoriated. Even Spanish churchmen who followed in the wake of the explorers became curious. They justified this new intellectual trait on the grounds that none of their authorities — biblical or ancient — knew anything about these strange continents accidentally discovered on the way to the Orient.

An avid appreciation for ancient philosophers created a whole new category — that of the humanists, who cultivated classical ideas and styles through a rigorous study of Greek and Latin. Greek and Roman thinkers had been famously curious, asking a myriad of questions about the heavens, the planets and earth’s human inhabitants. Reading their works couldn’t but nurture an investigative spirit. Responding to this, the humanists formed clubs to talk about the knowledge gleaned from the recovered texts. Their growing numbers signaled a discontent with the inward, logical reasoning of the Scholastics, who were the principal interpreters of the Christian dogma that had dominated thinking since Augustine’s time.

The new focus on the classics was not like sailing off into the Western Hemisphere, but studying Greek philosophy prepared some to ponder the puzzles that the discoveries turned up. Especially startling was Europe’s new location on the globe, no longer joined to the Middle East and Asia through a vast land bridge, but separated from Asia by two huge oceans and the linked continents of North and South America. Maps had to be redrawn and redrawn again as successive explorers returned with new sightings. Ironically, the fact that the existence of the New World was unknown to the ancient writers dented their reputation a bit. Greek geographers had planted serious doubts about there being life near the equator. Desiderius Erasmus, the great Dutch humanist, wondered in what other ways the ancients might be in error. This attitude of questioning, if pressed too far, led to conflicts with the Scholastics.

Turning toward this world, as ancient learning encouraged the humanists to do, meant attending to the objects people encountered every day — the animals, rocks, mountains, trees and stars — not to mention fellow human beings. Leonardo da Vinci’s many anatomical drawings exemplified this new fascination with the here and now. His accurate depictions of the human body merged art into scientific inquiry. Not until the nineteenth century did philosophers, mathematicians, artists and scientists go their separate ways. For three centuries, gifted amateurs in all these fields took the lead in examining natural objects, both domestic and foreign.

Printing with movable type, introduced in the second half of the fifteenth century, made the reproduction of writings and illustrations much less expensive than the written manuscripts that had preserved texts before. During these same decades, the reading public expanded with the switch from Latin to vernacular languages. Publishing and literacy enhanced one another as the catch basin for communication widened. The divergence of Greek learning from Christian cosmology added to the intellectual turmoil from the discovery of the New World. More and more men and women had to cope with the intrusion of novelty, but it would be a mistake to exaggerate the immediate impact. Still, there was a momentum going for new initiatives in exploration.

Greeks had long pointed to the Pillars of Hercules, the promontories flanking the Mediterranean’s opening to the ocean, with the warning ne plus ultra — go no farther. Portugal and Spain, facing the Atlantic, became the obvious kingdoms to reject this advice. During the 1580s and ’90s the Portuguese had been building victualing stations on African islands and for their commercial fleets en route to the trading centers in the East Indies. Meanwhile, a French navigator, Jean de Bethencourt, sailing for Castile in 1402, conquered the Canaries, which lay some 1,200 miles from Cadiz, winning for the Spanish a key station in the Atlantic. From the Canaries Spanish sailors could catch the best winds to carry them west. By the end of the fifteenth century, monarchs and financiers were ready to open up their purses to expeditions that would explore the world by sea.

Like Prince Henry, Columbus studied navigation. He made maps to depict his conjectures of what the globe really looked like. He also got in touch with Paolo de Pozzo Toscanelli, a Florentine astronomer and geographer of note, who had come into contact with writings long lost to Western Europe. Lorenzo the Magnificent had summoned an ecumenical council in 1439. The thirty-one Greek bishops who attended this extraordinary gathering brought with them the knowledge of ancient philosophy that had been preserved in the Byzantine Empire. They knew the speculations and experiments of the inquisitive Greeks. Toscanelli talked to these bishops in Florence, reigniting his zeal to figure out the shape of the earth.

It was one thing to know that the world was not flat and another to have an accurate idea of its size and shape. Europeans had neither. Worse, their heads were full of hideous pictures of what lay beyond the waters that lapped at their shores. Only with the great persuasive powers of a prince of the realm had Henry the Navigator got his sailors to press farther down the west coast of Africa. Most people believed that fantastic creatures inhabited the Ocean Sea, as they called the Atlantic. Others were sure that the bottom teemed with sinners who were burning in a molten mass that could suck in vessels that sailed out too far. Access to the writings of Strabo, a first-century Greek, dissuaded Toscanelli of the existence of these terrors. Strabo insisted that there was one world and it was habitable and its landmasses were joined by the Ocean Sea. Toscanelli went further and said that it would be possible to sail from Europe to India along the same parallel.

Men with grand visions like those of Columbus had existed before; he succeeded in implementing his plans because financiers, merchants and monarchs — usually given to caution — responded positively to his outsized ambition. Columbus’s plan contained two errors: he calculated that Japan was 2,400 nautical miles from the Canaries when it was actually over 10,000. As problematically, he did not anticipate there being a landmass between Europe and Asia! With the confidence of ignorance, he departed in August 1492 with some 120 men dispersed among two little caravels, the Niña and the Pinta and the larger Santa Maria.

Ardor for heroic adventures may have helped suppress the fear of Columbus’s seamen for what lay beyond the coastal waters. His sailors were lucky that Columbus knew about the clockwise circular wind patterns of the Atlantic, which would get them back home before exhausting their food supply. Elated by his success in making a landfall after nine weeks, Columbus sailed home convinced that he had found a landmass not far away from Asia whose store of riches he had read about in his favorite text, The Travels of Marco Polo.

In 1497 the king of Portugal commissioned Pedro Álvares Cabral to strengthen contacts with Asian merchants, sending him off with a fleet of thirteen ships. Blown off course in a storm, Cabral landed in Brazil and forthwith claimed it for Portugal before pushing on to India. Eager to tamp down the already disruptive competition between the two Catholic countries of the Iberian Peninsula, Pope Alexander VI had divided the globe between Portugal and Spain. Now he had to make a large jag in the established line (longitudes were then guessed at) to honor Portugal’s new possession.

Columbus’s discoveries were extraordinary enough to batter at the wall of inhibitions that surrounded questioning of Christian cosmology. There was no place in the European system of knowledge to fit in the plants, animals, minerals and humans he brought back. They challenged settled opinions and provoked unbidden questions; they tugged at the roots of faith. The voyages of discovery proved to be the catalysts for breaching the church’s curbs on curiosity, but it took time.

The intellectual consequences of Spain’s venture across the Atlantic long outlasted its empire. Slowly the age-old concern with acquiring wisdom through contemplation was pushed aside in the pell-mell search for mundane details about the earth and its contents. Old ways of knowing were turned upside down. A passion for collecting information through observation, measurement and description of new phenomena grew stronger, though it took successive generations to generate hypotheses about their meaning. This new form of pursuing information opened up the doors of inquiry to less educated amateurs, once excluded from the closed circles of the Scholastics and humanists who had to master ancient languages.

The engagement with natural phenomena involved Europeans in an inquiry about sex and sexuality. The nude bodies of the Amerindians provoked questions about the meaning of nakedness. Innocence and barbarity competed as answers. When explorers encountered willing sexual partners in the New World, their reports led to a new discourse about sexuality. Nor were sexual questions confined to humans. Botanists would use reproductive organs to categorize plants, and the sexual exclusivity among animals became the way naturalists defined species. Reproduction and the incorporation of new traits in the lineage of living things would form the basis of Darwin’s explosive explanation of human origins, bringing to a climax the four-century examination of natural phenomena that the discoveries of the world outside of Europe provoked.

No one had any idea of what would happen if ships sailed west across the Atlantic. Columbus’s sponsors certainly did not expect the most significant unintended consequences of all: the breaking open of the closed world of Christianity. A civilization marked by a reverence for sacred texts so deep that it disallowed questions about natural phenomena became the trailblazer in inquiries about nature. The Church Fathers had been correct. Curiosity was dangerous. Passing from amateur passions to sober investigations of biology, geology and astronomy, it upended the grand Christian narrative of the origins of life and the place of our planet in the universe. Over the course of four hundred years the research spawned by Columbus’s discovery of the New World set Europe apart from any other society on the globe, and, even more, from its own past.


Excerpted from Shores of Knowledge: New World Discoveries and the Scientific Imagination by Joyce Appleby. Copyright © 2013 by Joyce Appleby. With permission of the publisher, W.W. Norton & Company, Inc.

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