A take on how the scientific revolution happened
This piece proposes a speculation, or what I call a WAG, concerning how and why modern science appeared when it did. I have previously given an account of why it arose where it did, this piece is about why it happened when it did and what factors caused it to develop then.
To avoid confusion, I include a short glossary1 of terms that I will employ here that have specialized meanings in the context of the discussion.
The revolutionary change brought by gunpowder
My story begins with an earth-shattering event: the fall of Constantinople in 1453. With its impressive city walls, Constantinople was virtually impervious to attack, a barrier to Western Europe which multiple waves of onslaughts couldn’t break. During the 1453 siege, these walls were broken by use of advanced gunpowder artillery:
When the huge stone balls struck the walls at an advantageous spot, the effects were devastating. “Sometimes it destroyed a complete portion of wall,” an eyewitness reported, “sometimes half a portion, sometimes a greater or smaller part of a tower, or a turret, or a parapet, and nowhere was the wall strong enough or sturdy enough or thick enough to withstand it, or to hold out totally against such a force or the velocity of the stone ball.” It must have seemed to the defenders that the whole history of siege warfare was unraveling in front of their eyes. The Walls of Theodosius, the product of two millennia of defensive evolution, crumbled wherever it was hit. The defenders were amazed and horrified by what they saw.
Gunpowder cannon had brought down the greatest masonry fortification in history. Siege guns of this sort required a great deal of money to acquire and operate. This meant monarchs with access to cash revenues from customs and feudal levies from towns paid in cash rather than military service could acquire and use such wall-busting technologies while their vassals could not. Rebellious nobles could no longer count on the safety provided by their castles, which shifted the balance of power towards the monarchs. We see the Kingdoms of France and Spain joining England and Portugal as unified states, whose rulers would have ideas for expansion. Humans have a hard-wired drive to acquire prestige, to become one of the “cool kids.” Rulers are no exceptions. For them military success brings prestige.
As masonry fortifications became ineffective, they were soon replaced with earthworks whose construction favored inelastic contact with cannon shot, which spread the force of impact over a large volume, neutralizing the destructive effect of cannon. Such softer, non-rigid fortifications are easier to take by storm than high vertical walls and so require more men to defend. This and the rising power of ranged, gunpowder weapons relative to hand-to-hand combat meant rulers increasingly had Aragorn’s dilemma. Aragorn solved his need for more men with a magic sword, but earthly kings needed more prosaic solutions.
Figure 1. Soldiers per thousand population in the European Great Powers2
The solution to Aragorn’s dilemma: mo’ money
Figure 1 shows that they solved their problem. The combined armies of the Great Powers grew some 14-fold over 1500-1800. Some of this growth reflected rising population, but most of the growth was relative to population, which increased nearly seven-fold. “The sinews of war are infinite money,” as Cicero put it. The increase in manpower relative to population meant state rulers had learned to extract more money from those they ruled. How did they do this?
Figure 2. British economic growth and tax revenues over 1500-1800
Figure 2 shows the situation for Britain. Leaving aside the revenue spike in the 1540’s, the Tudors were able to raise revenue equal to 1.1% of GDP. The revenue spike reflected Henry VIII’s confiscation of church wealth:
Henry was an extravagant spender, using proceeds from the dissolution of the monasteries and acts of the Reformation Parliament. He converted money that was formerly paid to Rome into royal revenue.
The pre-Civil War Stuarts were able to raise even less revenue than the Tudors, averaging 0.8% of GDP, in a world engulfed by the Thirty Years War (see early 17th cent. spike in armies in Figure 1). Chronic financial crisis led to civil war (1642-51) and the execution of Charles I. The new government levied taxes above those of both the Stuarts and the Tudors. These revenues were used, among other things, for the first of the Anglo-Dutch wars. When the Stuarts returned to the throne, they averaged a tax rate of about 1.3%—slightly above the Tudor level—to raise 2.4X more revenue. This was used to prosecute two more wars against the Dutch.
The Glorious Revolution (1688) deposed Charles II and introduced government accounting such as that used in business, and a modern financial system in the form of a central bank, which increased the efficiency and perceived fairness of taxation, allowing two to three-fold higher tax rates to be tolerated without incurring another revolution. The substantial increase in revenue this brought paid for no less than five major wars over 1689-1783. The British government was able to raise more than seven times the pre-Glorious Revolution revenue in the 1790’s to meet the threat of the French Revolution.
Only about half of this additional revenue had come from the higher tax ratesl the rest came from economic growth. This seems obvious today, but this was a new phenomenon. Economic growth can be defined as rising economic production after correcting for population growth—that is, growth in real GDP per capita. Figure 2 shows a plot of real British GDP per capita. It is flat until around 1675, after which it began to rise. In fact, for the vast majority of the time since the rise of civilization there was no sustained increase in economic output per person. Although technological improvements that grew the economy in aggregate happened from time to time, these were accompanied by a rise in population so that the ratio between the two did not change much—a phenomenon called the iron law of wages.
The search for more money and more power
In such a world, a ruler needed more subjects to generate more revenue (and more military power), which meant they needed more territory. Hence wars were fought over territory, in which various monarchs contested for prestige in eyes of their peers by being the most badass conqueror. This idea of prestige is mirrored in the title of “the Great” used for some monarchs and not others, mostly based on their prowess as conquerors.
Imagine the situation rulers found themselves in around 1500. The nature of war had changed, more men would be needed to pursue prestige and so more revenue. But conquest was hard; all of the surrounding monarchs had the modern weapons. Rulers had a choice of taking on their neighbors, where victory went to those whose money ran out last, or to strike outside of Europe in search of easier domains to conquer and tax. The Spanish and Portuguese were the first to do so. Spain carved out a conventional territorial empire by conquering the rich, but less militarily advanced American civilizations, as Cyrus, Alexander and Pompey each had done with the rich lands of the Near East. Portugal sought a different way, attempting to capture the riches of the spice trade by finding a sea route to the Indies that circumvented the Venetian middlemen. In doing so they created a commercial empire, dominating oceanic trade and gaining the profits it generated.
In an effort to emulate them, the British and Dutch established East India trading companies around 1600 to take advantage of trading opportunities pioneered by the Portuguese. The English efforts were less successful than the Dutch and a far cry from the lucre the Spanish crown received from their New World conquests, which, by itself, was nearly as large as all English revenues in 1600.
If the English ruler was ever to be somebody, they need to find a way to generate more revenue from what they had. To this end they founded (or acquired by conquest) commercial colonies, unsuccessfully in North Carolina (1585), and successfully in Virginia (1607), Bermuda (1612). New Hampshire (1623), Barbados (1627), Nevis (1628), Montserrat and Antigua (1632), Jamacia (captured from Spain in 1655), South Carolina (1663), New York (founded by the Dutch in 1624, conquered by British in 1664), and Delaware (founded by Sweden in 1638, conquered by the Dutch in 1655 and then by Britain in 1664). These were successful in the sense that they created thriving self-sustained societies, but they did not do for Britain what the Mexican and Peruvian conquests had done for Spain.
This was not the only iron in the fire. From the days of Edward III (1327-77) revenues could be raised by the uncontroversial and traditional practice of levying taxes (custom duties) on trade. Custom duties were first introduced in England in 1275 and were uncontroversial by the 15th century. This meant another way to increase revenues for the Crown was to oversee the creation of new trades upon which a tax would be applied. One can see this as an “internal” version of the colonization strategy. New colonies or trades, being new, lack entrenched political interests to resist efforts to tax them. Thus, a sensible strategy to boost state power would be to encourage the development of new trades and then tax them.
Solution to the revenue problem: capitalism
How do you do that? A ruler can award prestige to those who create new economic activity, the taxation of which grows state revenue. Economic activity is the product of labor and labor productivity. Productivity is a function of the capital with which labor works. A state pursuing greater revenues would seek to create a class of individuals who accumulate productive capital as a symbolic prestige marker, that is, capitalists. Application of this growing capital increases productivity, GDP per capita and tax revenues. I cover this process in more detail here,
A ruler can grant prestige by bestowing honors such as knighthood on successful capitalists that serve as symbolic markers of prestige. A ruler can indirectly bestow prestige simply by respecting property rights, allowing such creators to safely flaunt the wealth that comes from capital accumulation. Wealth is another symbolic prestige marker. Prestige acquired by capitalists encourages others to do the same; engage in capital accumulation in order to grow the economy and state revenue in service of state objectives.
This plot shows the relation between rising per capita GDP after 1700 and cumulative surplus person-years. Surplus persons are the portion of the population over that needed to operate the pre-capitalist agrarian economy. Prior to the invention of capitalism, there was nothing productive for this surplus to do; they became paupers until they died from one of Malthus’s positive checks on population. Once on the scene, capitalists found productive things for people to do, and surplus population ceased to be a thing. Instead, population rose above the “Malthusian limit” of previous centuries. Once everyone was employed, wages would rise, incenting efforts to increase productivity that led to rising per capita GDP and living standards.
Scientific revolution as a response to capitalist demand
How did capitalists do this? They made use of new techniques that produced more of an existing product for the same cost than previous methods, or they started making and selling new things that people were willing to pay for that did not previously exist. In order to do this, capitalists needed new knowledge. But not just any sort of knowledge; practical knowledge (inventions) that could be employed in business (or the battlefield) to achieve real world results. That is, the knowledge had to be empirically demonstrable and usable by people other than the inventor (that is, replicable). This demand by capitalists for inventions led tradesmen, engineers, and other clever people to supply them, and the rate of invention rose as shown in Figure 3.
The raw material needed for producing inventions is knowledge of how the natural world worked. This was the domain of natural philosophers. The need for knowledge that worked reliably in the real world meant there was a premium value (in terms of prestige) placed on knowledge that was empirically validated. Natural philosophers who create empirically valid knowledge are what we call scientists. The scientific revolution was, in part, a response to this demand for inventions and for the knowledge that can be used to generate inventions.
Figure 3. Innovation rate in science and technology over the preceding 25 or 50 years.
Figure 3 shows the rate of innovation during the four centuries after 1500. The data shows similar (low) rates of scientific discovery and technological innovation during the sixteenth century which rose in the seventeenth century. At this early time capitalism was in its infancy and had a long way to go before it would make a significant impact. Scientists and inventors were often the same people, and the former were still categorized as natural philosophers in academia. But as capitalism began to make an impact on economic growth in the last third of the seventeenth century, the rate of invention began to rise above the rate of scientific advancement. Inventors and scientists were increasingly not the same people, though they would often work together.
Acceleration of the scientific revolution
A century of capitalism resulted in the evolution of a critical mass of businessmen, engineers and skilled craftsman capable of developing and commercializing new technology at an enhanced rate. Armed with previous technical discoveries, they did exactly that, giving rise to the industrial revolution. This is indicated in Figure 3 by the rise in invention in the latter half of the eighteenth century. It was at this time that intellectuals like Adam Smith first became aware of the capitalist revolution that had been underway for a century. In the absence of national economic statistics, the sort of changes I am talking about here are very difficult to see. An example of this is how Thomas Malthus introduced his theory more than a century after it had been made obsolete (in Britain) by the rise of capitalism.
The late 19th century shows a further surge in innovation that Brad DeLong explains was due to the “development and establishment of industrial research labs and modern corporations.” Up until around 1870, the process had been that capitalists took in inventions, mixed them with capital and workers to convert resources and labor into output, the sale of which produced sales and profits. A fraction of the profits was then reinvested back into the capitalist process to speed up the capital accumulation process—the holy grail of capitalism. This process could become limited by the supply of inventions. One way to overcome this limitation might be to apply capitalism to the innovation process itself. Rather than wait for the inventions to come to them, why not apply capital to the inventors to increase their productivity the way they did with ordinary workers? This is what the industrial research lab was about, and Figure 3 suggests they were on to something.
I spend my career working in an industrial research group as a bioprocess engineer and can personally attest to the increase in my own research productivity achieved by moving from grad school, where our research group’s progress was limited by skill at grantsmanship, to industry where research guidance and obtaining funding was handled by professional managers. My knowledge creation in industry was much faster and validation in the real world of the production plant was routine.
Even with industrial laboratories, there was still a limitation. Researchers like me work well within the scientific paradigm. At some point your research group will have done all their current knowledge can deliver. You need new science or technology from external sources. Here governments played a role similar to industrial research centers, but with a focus on basic research by funding university research in an effort to boost the rate of scientific discoveries.
Conclusion
We have seen a process in which the military revolution creates a state demand for increased revenue per subject. Obtaining this revenue requires growth in GDP per capita, which requires capital accumulation. That is, to deal with the demands of the military revolution, capitalism evolved. To feed capitalism, inventions and the scientific knowledge upon which they are based were required. To this end, science evolved.
Science: the objective observation, identification, description, experimental investigation, and validated explanations (theories) of social and natural phenomena, often making use of mathematics. The value of scientific descriptions and theories is ultimately based on their correspondence with empirical reality and ability to make predictions.
Capitalism: an economic system in which a country's trade and industry are controlled by private owners/managers (businesspersons) for profit. A subset of businesspersons (capitalists) manage the business and profits in such a way as to increase the capital they control.
Military Revolution a series of changes in war-fighting characteristics from the late 15th to the early 18th centuries that dramatically changed how wars were conducted in Europe.
Prestige: A property possessed by some people that makes others admire them, treat them deferentially, and see them as role models. Prestige is often signaled by the presence of symbolic markers such as wealth or honors. Most importantly, prestige promotes the spread of the beliefs and behaviors of the prestigious.
Austria, Britian, France, Germany, Netherlands, and Spain