Lecture 20

Enlightenment, or the Age of Reason.


Introduction

The last lecture saw the contradictions between the feudal European governments and the emerging bourgeoisie expressed through religious conflicts. When we now turn to the 17th and 18th centuries we shall see these contradictions intensify and prepare the ground for political revolutions. The intellectual climate to accompany this development was one of liberation from previous beliefs, dominated by the idea of personal freedom of thought and rational attitude to the study of the forces of nature.

The new rational attitude made the period between the Thirty Years' War and the French Revolution into the Age of Reason or the period of Enlightenment (German Aufklärung, French Siècle de Lumières). The move towards a new society took different directions in the different parts of Europe. The most important developments took place in England and France. Although the driving forces for change were the same and the developments in the two countries were intimately linked, the results were very different.

Europe before the French Revolution

In France the Calvinist reformation had established itself as the Huguenot movement, which aimed at taking over control of the country. The Huguenot wars of 1562 - 1594 had ended in disastrous defeat. Thousands of Huguenots were slaughtered during the Saint Bartholomew's night massacre of 1572, and the declaration of an independent Huguenot state in southern France could only delay the victory of the autocratic forces. Huguenot refugees had found new homes in Germany.

Half a century later France had emerged from the Thirty Years' War as the leading power in western Europe, its autocratic feudal state structure not only intact but considerably strengthened. France's fledgling bourgeoisie thus had to look after its economic interests in the framework of a feudal state. Recognizing the need to develop the infrastructure of the country to allow it to compete against Holland and England, king Louis XIV promoted the construction of roads, canals and ports, but he also spent lavishly on extravagant projects such as Versailles and established himself as the ultimate incarnation of the absolute monarch, declaring: "L'état, c'est moi" ("I am the state"). As a result, autocratic feudalism survived in France until 1789, when it was swept away through the French Revolution.

In England the end of feudalism came earlier, but in instalments. The power of the Catholic church in England was not broken by public unrest but by royal decree of king Henry VIII, who declared the separation from Rome and establishment of the Church of England in 1532 for the sole purpose to divorce his first wife Catherine. (Divorce was not an option for Catholics.) During the years that followed he disbanded the monasteries and handed their land over to the aristocracy.

The main economic activity was sheep farming pursued by feudal landlords, but the lucrative wool trade, which could have strengthened a merchant class, was controlled by the Dutch cities. The large sheep estates had been created during the first half of the 16th century through expropriation of the villages which - like villages on the continent and elsewhere - had traditionally given their peasants temporary access to land for the planting and harvesting of crops but kept the land as common property. Through the process of progressive "enclosure" (surrounding of parcels of land with hedges or fences) the English aristocracy had excluded the peasants from the use of their land.

By the late 15th century many homeless peasants roamed the country. An act of 1495 introduced prison terms for begging and vagrancy. But the closure of the monasteries had meant an end to church support for the poor, and prison terms did not reduce the general poverty. A second act of 1547 allowed the use of beggars as unpaid labour. When the peasants rose in revolt in 1549 the government brought in foreign mercenaries to defeat them. (Anderle et al., 1966) The third act against vagrancy of 1597 had to include an acknowledgment of the state's responsibility for the welfare of the poor but increased the penalties for the "undeserving poor" (those who refused to work for low or no wages).

England's aristocracy had gained control over the countryside at home but watched the developing colonial trade with concern. The Dutch challenged the Spanish/Portuguese sea monopoly by establishing the Dutch East India Company and commissioning Hugo Grotius to justify their attempt at gaining access to the spice trade. Grotius declared that the ocean is the property of all and that national claims do not extend beyond 3 nautical miles from the shore (the distance of a cannon shot at the time).

To participate in the expected colonial windfall England sent exploratory mission into all parts of the world. The first person to sail around the world in 1519 - 1521, Fernão Magalhães (Magellan), had been Portuguese. The second and third, Francis Drake in 1577 - 1580 and Thomas Cavendish in 1586 - 1588, were English. (The goods obtained in Chile and Peru by Drake gave him and those who financed his voyage a profit of 4,700 per cent; Anderle et al., 1966) Others remembered for their exploratory voyages include John Davis, explorer of the Davis Strait between Greenland and North America, Henry Hudson who explored the Hudson Bay of Canada, and William Baffin, explorer of Baffin Bay north of the Davis Strait. (The Hudson's Bay Company, established in 1670, still operates in real estate and natural resources today, with headquarters in Toronto, Canada.)

The decision which country would dominate the seas for the next 300 years came in 1588, when the fleet of Elizabeth I defeated the Spanish Armada. A decade later, in 1600, Britain established its own East India Company.

England was now in a position to rival Holland and France as an economic power, but the question of who held political power was still not settled and eventually was fought out in a civil war. The Civil Wars of 1642 - 1646 and 1648 - 1650 saw the reactionary royal forces face the parliamentary forces for a republic under the command of Oliver Cromwell. England was declared a republic in 1648; king Charles I was executed. Three years later the Navigation Act of 1651 reserved all transport of imported goods to English ships only. It had to be enforced by war against Holland in 1654.

The Civil Wars replaced the feudal regime of the monarchy by the bourgeois republic; they were England's bourgeois revolution. Like all revolutions they could only be successful through the participation and support of the common people. But the landless peasants and other poor fought against the monarchy to improve their lives, not to install a bourgeois government that would continue their suffering. The republican government was very aware of this, and the control of the armed forces - made up by common people in arms - was one of its greatest concerns. When public unrest threatened to grow out of control the bourgeoisie decided in 1660 to call king Charles II, the son of Charles I, back from exile.

King Louis XIV of France, who was greatly concerned about the establishment of a bourgeois republic in England, saw the return of the Catholic Charles II to England as an opportunity to turn back the development. He subsidized Charles II financially to re-establish autocratic rule. This was of course not what the bourgeoisie had had in mind when it had invited Charles II back. To ask the common people again for help was too great a risk, so in 1687 parliament turned to the Protestant William of Orange of Holland for help to depose James II, the autocratic son of Charles II, but this time under strict terms of agreement.

William's victory over James II in 1688 known as the "glorious revolution" marks the beginning of the British system of constitutional monarchy with an elected lower house (Parliament) that exercises political power and an upper house (House of Lords) where members of the old aristocracy exercise their feudal right to be members by birth. Among the various laws William signed during his reign were the Habeas Corpus Act (no arrest without cause), the Toleration Act (guaranteed freedom of religion), the Act of Settlement (independence of the judiciary) and the Bill of Rights (regulation of the role of king and parliament).

By the end of the 17th century England was thus the first country in which freedom of thought had been legally established. To demonstrate the difference between England's bourgeois government and Europe's feudal states of the time we have a very brief look at other European countries at the beginning of the 18th century.

The Thirty Years' War had left Germany weakened and divided. The German rulers watched the development in England and realized that they, too, had to modernize their countries or fall further behind. The two strongest political royal powers in the German realm were Maria Theresia of the Habsburg dynasty, who ruled over the Austrian-Czech-Hungarian conglomerate, and the Prussian king Frederick II the Great. Both initiated reforms but kept power in the hands of the absolute ruler; where they restricted the influence of the feudal aristocracy they did it not to increase the power of the bourgeoisie but with the aim to strengthen their own position.

Maria Theresia abolished tax exemptions for large landowners, secured the independence of the judiciary from the political administration, introduced textbooks into the universities and reorganised the university administration. But she did not increase the autonomy of the universities; on the contrary, she reserved the right to veto the election of faculty deans for herself. Forced by a peasant revolt she recognized the need for a public health system and support for the poor. A pious Catholic, she did not promote new ideas, and the bourgeois spirit of individual freedom of thought had no place in her reign.

A similar development occurred in Prussia. When king Frederick I died his son Frederick the Great declared that from now on all political decisions would be made only by him. His subjects had to suffer greatly from wars that cost the lives of more than 180,000 soldiers and caused widespread hunger. When Frederick learned about the introduction of the potato from South America and its value as low-cost staple food, he ordered the peasants to plant the new crop and used his troops to enforce the order.

But Frederick was an absolute monarch who admired the Enlightenment. He practiced religious tolerance and allowed more than 300,000 religious refugees of all denominations into his country, so that by the end of his reign 15% of the population was not born in Prussia. He introduced compulsory primary education into every Prussian village. He invited intellectuals from other countries to come to his residence in Berlin, hoping to establish a centre of modern thought for Europe. But the Prussian climate of discipline and militarism kept the scholars of the time away. (Voltaire, who had attracted the wreath of Catholics and Protestants alike, accepted the invitation and managed to live in Berlin for three years before he, too, left for Switzerland.)

The intellectual climate 1648 - 1789

To understand the development of science in the time before the bourgeoisie came to political power we have to have a clear perception of the intellectual climate of the time. We have to remember that much new information flooded the cities of Europe. Extraordinary tales from unknown continents reached the ports and came as leaflets and brochures from the printing presses. Could you trust those stories of unseen riches and strange animals and people? The debate over the structure of the solar system and the incredible consequences of the Copernican system occupied peoples' minds everywhere: How could it be that the Earth revolves around the Sun or rotates around its own axis, yet we do not feel it?

There has rarely been a time in history when the talk at afternoon tea parties and in after dinner smoking rooms was dominated by questions of science as much as during 17th and 18th century Europe. Anyone who planned to get ahead in society had to be in touch with the latest discoveries. Armillary spheres and globes of the terrestrial and celestial variety became must-have items and conversation pieces for every bourgeois household and were manufactured in large numbers. The learned gentleman of bourgeois standing would even carry a pocket globe on his travels.

It is important to realize that despite Galilei's convincing observations the question whether the true character of the solar system was better described by the Copernican or the Ptolemaic system was still not settled. More than 25 years after Galilei's death the Dutch map maker and engraver Cellarius published his star atlas, which still showed "the World according to the Ptolemaic and the Copernican hypothesis" and included for good measure a compromise developed by Tycho Brahe, in which Sun and Moon circle the Earth but the other planets revolve around the Sun.

Debating circles sprang up everywhere, many as a means to improve the social standing of the host, but many also for the purpose of scientific study. Public lectures attracted large audiences, and scientific demonstration experiments became an element of public entertainment. To assist the exchange of views, plan and report on new experiments and formulate important new questions, scientific academies were established in all major European countries.

The best country to lead the debate and develop new ideas was England. Desiderius Erasmus had lectured in Cambridge from 1509 to 1514, and both Cambridge and Oxford had become centres of humanist teaching. The Civil Wars and the "Glorious Revolution" had established a bourgeois government that guaranteed freedom of thought. England was therefore the first country to have its own Academy of Science, closely followed by France:

Foundation dates of scientific academies
1660 Royal Society of London
for the Promotion of Natural Knowledge
1666 Académie des Sciences (France)
1700 Akademie der Wissenschaften (Germany)
1724 Akademiya Nauk (Russia)
1743
1780
American Philosophical Society (USA)
American Academy of Arts and Sciences (USA)

 

During the 18th century England was the first country to finance a large scientific expedition across the world ocean. In 1768 its government sent James Cook to Tahiti in the South Pacific to observe the transit of planet Venus across the Sun. Following that assignment Cook was to find and explore the land of the southern hemisphere that, according to Ptolemy, existed to counterbalance the land mass of the north. Expressed as a percentage of the British state budget of the time the expense is comparable to the cost incurred by the USA when it decided to get a man to the Moon.

Science in the 17th and 18th centuries

The major stumbling block for the general acceptance of the Copernican system was that it had created more problems than it had solved. According to Ptolemy the universe was governed by two types of movement: Objects close to the centre of the universe fall to the centre, while objects at the outside of the universe move on circles. If the Earth was no longer at the centre of the universe, why do objects fall to the ground?

Galilei had spent much effort on this problem. Through experiment he had established that all objects regardless of shape or size fall with the same speed (if one disregards the frictional effect of the air). By observation and measurement he had shown that the distance fallen is proportional to the square of the time that passes and had derived the shape of the path of a projectile as a parabola. One of his most important conclusions was that it is impossible to decide whether a body is at rest or moving at constant speed:

"Motion, insofar as it is and acts as motion, to that extent exists relatively to things that lack it; and among things which all share equally in any motion, it does not act, and is as if it did not exist." (quoted from Westfall, 1971)

How much Galilei's thinking was still influenced by Ptolemy can be seen it his distinction between "natural motion" and "motion which is not natural." Galilei defined two types of "natural motion," the free fall - for which he had developed the correct description - and movement on circles. (An example of "not natural motion "is the motion of a cannon ball: It is produced by the combination of free fall and an initial thrust.) Like Ptolemy, Galilei explained motion as if it were a property of the moving bodies:

Newton's Laws; the Universal Law of Gravity

To establish the correctness of Copernicus required two major steps: Motion had to be understood not as a property of bodies but as the result of acting forces; and gravity had to be understood not as a tendency towards a centre but as a property of matter.

Scientists in several countries - Christiaan Huygens in Holland, Robert Hooke and Isaac Newton in England, Gottfried Leibnitz in Germany - were working on the problem. The key to the understanding of forces in circular motion came from Kepler's observation that planetary orbits were not circular but elliptic and from his law that the planets move faster when they are closer to the Sun. This led to the understanding of revolving motion as a balance of the centrifugal force and the gravitational force: When a planet gets closer to the Sun it experiences a larger gravitational attraction from the Sun. To balance it and stay on orbit it has to increase the centrifugal force by a corresponding amount and therefore moves faster in its orbit.

In 1679 Isaac Newton formulated the result of the analysis in three laws:

Newton's Laws, as they have been called ever since, were the cornerstone of the study of motion until the arrival of the theory of relativity in the 20th century and remain the basis for everyday physics. Aerodynamics, fluid dynamics, hydraulics and many other areas of science are based on them; the daily weather report is derived from a numerical model of atmospheric motion based on his second law.

Newton himself described his first two laws as inherited from Galilei; but as we have seen Galilei did not think in terms of forces and would not have formulated the laws in Newton's words. More importantly, Newton owed the inspiration to his second law to Hooke, who had outlined his ideas in a letter to him and later accused Newton of plagiarism.

But Hooke, who described the interplay between centrifugal force and gravitational attraction correctly, did not quantify it, as Newton's Second Law does. In today's notation it states that if a force F acts on a body of mass m, the resulting acceleration a is given by the relationship

F = ma

Newton's own contribution goes further than that. By careful quantitative analysis of Kepler's observations he deduced the Universal Law of Gravitation in 1684: Any body of mass M at distance r from another body of mass m exerts a gravitational attraction g on that body that is proportional to the product of the two masses and inversely proportional to the square of their distance, or

g = (G M m) / r2

where G is the universal gravitational constant.

Newton's Laws expressed a totally new understanding of nature. Gravity was now recognized as a universal property of all matter, a place vacated by motion, which now was the result of a balance of forces. It was this shift in the general understanding of nature that decided the argument between the Ptolemaic and Copernican systems and established the latter - with Kepler's corrections - as the correct description of the solar system. It also opened the way for the understanding of other natural phenomena: In 1740 Bernoulli showed that ocean tides are the result of the gravitational attraction of the Moon and the Sun. His theory of the "equilibrium tide" was a scientific breakthrough; before him tides were explained as being generated by the ocean breathing in and out and other unscientific ideas.

Quantification of science; the calculus

The new insight into the laws of nature had another important consequence: It fostered the desire for quantitative understanding. If motion is the balance of forces, how exactly do the forces balance? It was known since antiquity that if a body moves from place A to place B in the time span Dt and the distance between A and B is Dx, its velocity is v = Dx/Dt. (A car that takes 2 hours to travel a distance of 80 km travels at a speed of 80/2 = 40 km/h.) But Newton's Second Law does not quantify velocity, it quantifies acceleration, ie. the change of velocity with time. How, then does one determine a velocity if it changes all the time, like the velocity of planets on elliptic paths?

To determine changing velocities required new mathematical techniques, known today as calculus. They were developed independently during the same time by Newton in England and by Leibnitz in Germany.

The development of the calculus was a vital component of the new physics. Without it Newton's Laws could have only resulted in an improved philosophy of nature. The calculus allowed quantification of processes; it opened a totally new discipline, the quantitative study of forces, for which Leibnitz coined the name "dynamics."

Newton must have seen this clearly. While he had no problem to acknowledge priority of thought (somewhat too generously, as we have seen) for his First and Second Law to Galilei, he was furious when he learnt about the work of Leibnitz and went on a vitriolic attack, accusing Leibnitz of plagiarism and fraud. Leibnitz was rather baffled by this and did not respond in kind.

A closer look at the lives of Newton and Leibnitz can assist our analysis of the social conditions under which science developed during the Enlightenment. Newton lived and worked in England, the country of free thought and private initiative. As professor of mathematics at Trinity College in London he had all facilities to perform new experiments at his disposal and was paid to move science forward.

Convinced of his own grandeur and unable to tolerate the slightest criticism, Newton used his position to crush opponents wherever he could. He wrote articles to defend his priority of thought over Leibnitz and had them published under the names of his students. It is indeed doubtful whether under today's norms of ethical behaviour in science he would not have been dismissed from the university.

But Newton was not so much interested in science as in his position in the new emerging society. At the age of 54 he was appointed warden of the mint and retired from scientific work. He continued to be honoured by the ruling class, was knighted and became president of the Royal Society, a position he abused for his continued crusade against Leibnitz.

Leibnitz lived in Germany and had to follow his scientific interests under the conditions of a feudal state. Not being of noble stock himself, he had to procure his living through whatever employment he could find. Working for feudal rulers of small dukedoms he spent his time on the construction of hydraulic presses, wind mills, clocks and carriages, worked as a mining engineer and assisted in the organization of the education system.

Most of Leibnitz' scientific achievements resulted from a five year period when he was unemployed and found the time to apply his mind to unresolved issues of science. The fruit of this short time span was enough to spread his fame across Europe. The French Academy of Sciences made him a foreign member, and he was instrumental in establishing an Academy of Sciences in Berlin.

It is often said that during the 17th and 18th centuries science was "pure science", ie. science not determined by the needs of society, and that its development can therefore be understood and analyzed without reference to the great social upheaval of the time. Westfall, for example, argues that the science of Newton was not driven by "technological problems set by the economic system."

This description of 17th century science is correct if one defines the impact of the social and economic system through the demand for technological solutions to practical problems. But for millennia before the 17th century science and technology had been separate activities, and their close alliance to which we are used today was only just developing during the Enlightenment. The time were much if not most science is undertaken for technological innovation had not yet arrived. A first hint at such development may be seen in Leibnitz' life: He most certainly used his deep understanding of the dynamics of forces to improve the suspension of the duke's carriages and the efficiency of his mills, but his achievements as a scientists and mathematician were not the result of improved carriage suspensions.

Using technological problems as a yardstick for the degree of social and economical conditioning of scientific activity may be a way to analyze the development of modern science, which we will have to explore in later lectures. Using it for the 17th century cannot lead to a correct analysis. As we have said on several occasions before, science develops where a need arises, and the need of the 17th century was to resolve the Ptolemaic-Copernican controversy.

This need had taken on a new urgency with the expanding activity in world-wide navigation that required a better astronomy. To settle the controversy once and for all was therefore not just an academic dispute but occupied the minds of all debating circles of society. Without the intellectual climate of the time Newton, Leibnitz and others would not have achieved what they did achieve; they possibly would not even had come upon the questions that did occupy their lives under the given circumstances.

Experiment, craftsmanship and applied science

The step from qualitative description of nature to quantitative analysis and prediction of its dynamics was not restricted to questions of astronomy; it sparked scientific activity in many fields and led to the invention of scientific instruments specifically designed for the quantification of physical observations.

In Italy Evangelista Torricelli, Galilei's successor in the chair of mathematics at the Academy of Florence, continued Galilei's tradition of experimentation. By filling a tube with mercury and inverting it into a dish he developed a method to produce a sustained vacuum and invented the barometer to quantify variations in atmospheric pressure. Pascal used his instrument to show that air pressure decreases with height. Both judged their mathematical work as more important than their experiments in physics - Torricelli never published anything about the barometer, work for which he is mainly known today.

Galilei had tried to use the same method to establish an objective measurement of heat by placing an inverted air-filled tube in a liquid and varying the liquid's temperature, causing the liquid in the tube to rise against the air inside. But the liquid level in the tube depended both an its temperature and on the prevailing air pressure, and attempts to eliminate the effect of air pressure through the use of a closed tube proved technically too difficult. Daniel Fahrenheit developed the first working thermometer in 1709 and introduced a temperature scale. Alternative temperature scales were developed by Réaumur in France and by Celsius in Sweden. The three men again illustrate how science in the 18th century was moving closer to technology and engineering: Celsius was a professor of astronomy, Fahrenheit a maker of scientific instruments, Réaumur an industrial scientist and inventor who had compiled an inventory of France's natural resources at the request of the king.

Christiaan Huygens, to whom Newton owed much when he developed his ideas, contributed to improved measurement of time by inventing the regulation of the speed of clocks with a pendulum. Despite his outstanding work Huygens lived most of his life in the shadow of others; his groundbreaking theory of light had to wait another 150 years before it found widespread use.

The new attitude to experiment as the basis for scientific investigation also led to an appreciation of craftsmanship and artisans and thus prepared today's close association of science with technology. Before Galilei most students at universities would laugh at the idea that anything could be learned from men whose knowledge was gained only through practical experience. The English chemist Robert Boyle expressed the position of the Enlightenment when he said that

"many phenomena in trades are, also, some of the most noble and useful parts of natural history; for they show us nature in motion, and that too when turn'd out of her course by human power; which is the most instructive state wherein we can behold her. And, as the observations hereof tend, directly, to practice, so may they also afford much light to several theories."

Scientists of the Enlightenment did not refuse to work on problems of practical applications. An analysis of four years of the Royal Society shows that of the topics discussed at its meetings 59% were "(potentially) useful in one way or other" and only 49% could be classified as "pure science." (Hall, 1983)

On the continent the link between science and its immediate practical use was probably even stronger, since scientists were state employees and could be ordered to apply their skills to military or other problems at any time. Westfall (1993) analyzed the work and lives of 630 scientists of the time and concluded that only 148 of them, or 23.5%, never concerned themselves with technological applications.

Summary

References

Anderle et al. (1966) Weltgeschichte in Daten. VEB Deutscher Verlag der Wissenschaften, Berlin.

Hall, A. R. (1983) The Revolution in Science 1500 - 1750. Longman, London.

Westfall, R. S. (1971) Force in Newton's Physics, the Science of Dynamics in the Seventeenth Century. Macdonald, London.

Westfall, R. S. (1993) Science and technology during the scientific revolution: an empirical approach. In J. V. Field and F. A. J. L. James (eds.): Renaissance and Revolution; humanists, scholars, craftsmen and natural philosophers in early modern Europe. Cambridge University Press, Cambridge.


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