Unit 4.8 — 1450年至1750年间的延续与变化

European overseas expansion between 1450 and 1750 is often remembered by the shorthand "God, Gold, and Glory," and the documents here show all three motives genuinely present at once — but they also show economic motive steadily crowding out the other two as the period goes on, from an early mix of trade and crusading zeal into a mature system in which chartered companies wielded government-level power specifically to protect profit. Economic motives were not the only driver of European expansion, but they were the most consistently dominant one, both because they appear in every phase of the period and because, by the seventeenth century, they had absorbed the political and religious justifications that once stood beside them.

Contextually, none of this expansion was possible before the technological base of the caravel, the magnetic compass, and the mariner's astrolabe let Iberian sailors travel reliably out of sight of land — tools refined from Chinese, Islamic, and Indian Ocean origins rather than invented in Europe. Once that technology existed, the state-sponsored program built by Prince Henry the Navigator at Sagres shows economic motive was present from the very start of organized European exploration, but never alone. Document 1 is drawn from Zurara's own Chapter VII, where the royal chronicler lays out five reasons for Prince Henry's voyages in ranked order; the passage quoted here is the second of those five, describing the hoped-for "ready market" for merchandise and the "great profit" trade would bring — sandwiched between a first reason built on zeal to serve God and King and a fifth reason devoted entirely to spreading the Christian faith. Zurara was the court chronicler writing under Prince Henry's own patronage, so his account naturally frames the prince's motives in the most flattering light, and a reader should be cautious about taking his ordering and phrasing as a neutral inventory of Henry's true priorities — but even a chronicler working to celebrate his patron could not write commercial motive out of the story entirely.

That same blend of religious and economic motive appears on the water a generation later. Document 4's anonymous crew member, arriving in India with Vasco da Gama's fleet, gives possibly the most economical two-word summary of European motive in the whole unit: "Christians and spices." Coming from someone physically on the voyage rather than someone writing from a royal court, this document's historical situation — a sailor's own account of what his expedition was actually chasing — corroborates that ordinary participants understood the enterprise as inseparably religious and commercial at once, not purely profit-driven.

Economic motive becomes harder to separate from raw political control once colonization actually begins. Document 2 shows Columbus, writing directly to the official who helped finance his voyage, promising gold, spices, cotton, and enslaved people "as they choose to send for" — a letter whose purpose was explicitly to secure continued Spanish funding, which explains why it foregrounds exactly the material rewards Columbus knew his audience wanted to hear about. Document 3's Treaty of Tordesillas then shows Spain and Portugal translating that promised wealth into a formal, government-level division of the entire unclaimed world along a line drawn purely by mutual agreement between two crowns — evidence beyond the documents that reinforces this: the treaty's casual assumption that Christian monarchs could partition inhabited land between themselves shows how completely economic ambition had already fused with claims of political and religious authority by 1494.

Document 5 supplies the clearest counter-evidence that greed, not policy, was what actually governed conduct on the ground: Bartolomé de las Casas — a former encomienda holder writing after renouncing his own claim to Indigenous forced labor — described Spanish colonists turning on Indigenous peoples "like fierce wolves and tigers and lions." Las Casas's purpose in writing was to persuade the Spanish crown to restrain colonial abuses, so his account should be read as a deliberately urgent brief for reform rather than neutral reporting, but his firsthand experience as a former colonist gives his description of naked economic exploitation on Hispaniola real evidential weight.

By the seventeenth century, economic motive had absorbed political and even military authority outright. Document 6's VOC charter granted a commercial company the power to sign treaties with foreign rulers and wage defensive war in the name of the Dutch state — a government handing sovereign powers to a trading company purely so it could better protect its own profits, which is a qualitatively different arrangement from Prince Henry's court-sponsored voyages two centuries earlier. Document 7's Bosman, a company employee describing the mechanics of examining and purchasing captive Africans on the Gold Coast, writes with the flat, procedural tone of a merchant recording routine business practice; his historical situation — an insider embedded in the Dutch trading system rather than an outside critic — shows just how thoroughly the pursuit of profit had normalized the commodification of human beings by the early eighteenth century.

Taken together, the documents show economic motive present in every phase of the period, but not acting alone: it began the fifteenth century intertwined with religious crusading zeal, and it ended the period having absorbed political and military authority into itself entirely. The clearest complexity is this shift in ratio rather than a simple constant — expansion in 1450 was economically motivated among several comparably weighted motives, while expansion by 1700 had folded God and Glory into an economic system so completely that a trading company could make war in a king's name.

When Spanish and Portuguese ships began crossing the Atlantic regularly after 1492, they carried more than crops and settlers — they carried pathogens that would empty out the very workforce colonial economies depended on. The disease side of the Columbian Exchange is a necessary starting point for any explanation of why the Atlantic slave trade grew into a system moving millions of people, but it was not sufficient by itself: European colonizers' choice to solve their labor problem specifically through the racialized, hereditary enslavement of Africans, rather than through some other available option, was shaped just as heavily by the profitability of the cash crops those colonizers had already chosen to grow. The Columbian Exchange's demographic catastrophe was the trigger that created the labor emergency, but the specific, sustained, and expanding form that emergency took — the transatlantic slave trade — was equally driven by an independent economic logic that would have pushed colonizers toward large-scale coerced labor even without the scale of Indigenous population loss that actually occurred.

Some historical context makes the starting point clear. Portuguese and Spanish sailors of the fifteenth and sixteenth centuries had already assembled the caravel, the magnetic compass, and the mariner's astrolabe — tools refined from Chinese, Islamic, and Indian Ocean origins — into a package capable of sustained transoceanic travel. That technological base is what made Columbus's 1492 voyage, and the sustained contact between hemispheres that followed it, possible in the first place; without it, the entire causal chain this essay traces could not have begun.

The disease side of the exchange did the initial damage. Smallpox, measles, typhus, and influenza moved through Indigenous communities in the Americas faster than Europeans themselves could travel, and because centuries of isolation from Afro-Eurasia had left Indigenous populations with no prior exposure to these pathogens, the result was a demographic catastrophe historians estimate killed between fifty and ninety percent of the pre-contact population within a century. Spain's existing coerced-labor systems could not absorb a loss of that magnitude: the adapted Incan mit'a rotation and the newly created encomienda system had both been built around a labor pool that disease had just cut down by half or more, leaving colonial mines and estates structurally short of workers almost as soon as they were established.

Yet the labor shortage alone does not explain why the solution took the specific shape of Atlantic slavery rather than, say, indentured European labor or a scaled-back colonial economy. That shape came from what colonizers were trying to produce. Sugar cultivation in the Caribbean and Brazil was extraordinarily labor-intensive and extraordinarily profitable within the mercantilist logic that treated colonies as sources of raw wealth for the mother country, and it was precisely that profitability that made plantation owners willing to organize an entire three-leg triangular trade system — manufactured goods to West Africa, captives across the Middle Passage, plantation goods back to Europe — to keep the labor supply flowing continuously rather than treating it as a one-time replacement for a lost Indigenous workforce. The scale bears this out: roughly twelve million Africans were transported across the Atlantic between the late fifteenth and early nineteenth centuries, a number driven upward across three full centuries by ongoing sugar demand, not merely by the one-time demographic shock of the sixteenth century.

The strongest complexity in this argument is that the demographic-collapse cause and the profit-driven cause were not competitors but reinforcing partners operating on different timelines. Indigenous population loss explains why coerced labor became urgently necessary in the first place and why colonizers looked outside the Americas for workers at all; the profitability of sugar and other cash crops explains why that coerced labor persisted, expanded, and became specifically and permanently racialized across the following two centuries, long after the initial sixteenth-century population collapse had already run its course. Treating either cause alone as sufficient understates the case: it was disease that opened the door, but sustained colonial profit that kept the door propped open for three hundred years.

(a) The magnetic compass is a strong example: Chinese navigators were using it for maritime direction-finding by the eleventh century, roughly two hundred years before European sailors adopted and refined it into a tool for open-ocean travel in the fifteenth and sixteenth centuries. (The mariner's astrolabe, which passed from Greek astronomy through Islamic scholarship before reaching Iberian sailors, or the lateen sail, borrowed from Indian Ocean dhow design, would also earn credit here.)

(b) Columbus's 1492 voyage is best explained through the Gold motive: Columbus sailed west across the Atlantic under Spanish sponsorship specifically to find a direct sea route to Asian markets that would let Spain bypass the overland middlemen who controlled the existing Silk Road and Indian Ocean trade networks, and his own writing to the Spanish crown promised gold and profitable goods as the payoff of the voyage. (Da Gama's 1498 voyage combining Christian alliance-seeking with the spice trade, or Prince Henry's Sagres-based program mixing anti-Muslim crusading aims with the search for African gold, would also earn credit.)

(c) The treaty reflected the assumption that Christian European monarchs held the automatic right to claim and divide newly encountered land between themselves purely by mutual agreement, with no consideration given to the political authority, land rights, or consent of the Indigenous peoples who already inhabited the territory being divided.

(a) The Fronde pitted French nobles and the regional parlements against the centralizing authority of chief minister Mazarin during Louis XIV's minority, and it counts as internal because the nobles and parlements resisting the crown were already subjects operating inside the French state's existing legal and political structure — they were fighting over how an authority they already lived under should be exercised, not whether it should exist at all.

(b) The Pueblo Revolt of 1680, led by the religious leader Popé, who coordinated dozens of Pueblo communities across a roughly 400-mile network using knotted cords to synchronize the uprising date, was caused directly by decades of forced labor under the Spanish encomienda system combined with Spanish missionaries banning traditional Pueblo ceremonies and destroying sacred kivas — a direct assault on both the labor and the religious practice of a population that had never consented to Spanish rule in the first place. (Metacom's War, Maroon communities such as Palmares, or Ana Nzinga's resistance in Ndongo and Matamba would also earn credit with an appropriately specific cause.)

(c) An internal challenge sought to renegotiate the terms of an authority relationship that already existed — French nobles wanted to limit how far Mazarin's crown could centralize power over them, not to escape French rule altogether — while an external challenge sought to reject an authority relationship that an outside power was trying to impose for the first time, as when the Pueblo peoples fought to expel Spanish rule from territory Spain had never legitimately governed by Pueblo consent.

(a) The potato, carried from the Americas to Europe as part of the Columbian Exchange, produced far more nutrition per unit of cultivated land than traditional European grains such as wheat, and it grew successfully in the cold, wet climates where those grains often struggled. Its adoption expanded the food supply available in parts of northern and eastern Europe, and that expanded food supply supported measurable population growth in the regions that took it up over the following century.

(b) Under mercantilism, a European state typically required its colonies to ship raw materials — such as sugar, tobacco, or silver — back to the home country and then purchase manufactured goods made from those same raw materials from the home country, rather than trading freely with other states or manufacturing goods themselves. This policy kept the colony functioning as a captive market and supplier, which was meant to keep the balance of bullion flowing toward the home country rather than its rivals.

(c) The joint-stock company let multiple investors pool their capital and share both the risk and the profit of a voyage, so that no single wealthy individual had to bear the full cost of financing an oceangoing expedition alone. The VOC extended this model further by holding a government charter that granted it not only a trading monopoly but state-like powers — building forts, raising armies, and negotiating treaties — which let it sustain a permanent, ongoing presence in Asia instead of financing only a single voyage at a time.