THE ENLIGHTENMENT
CHAPTER 17 PP. 542-569 FROM PRENTICE-HALL
WORLD HISTORY (2007)
Background to the Revolution
Medieval scientists, known as “natural
philosophers,” did not make observations
of the world and nature so much as rely
on ancient authorities, especially Aristotle,
for their scientific knowledge. 
Changes in the 1400s and 1500s caused
European scientists to adopt new views
and methods.
(pages 511–512)
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Background to the Revolution (cont.)
Renaissance humanists studied the newly
discovered works of Ptolemy,
Archimedes, Plato, and other ancient
thinkers. 
They learned that some ancient thinkers
had disagreed with Aristotle and other
accepted authorities.
(pages 511–512)
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Background to the Revolution (cont.)
Technical problems, like calculating how
much weight a ship could hold, spurred a
movement towards observation and
measurement. 
New instruments like the telescope and
microscope made fresh observations and
discoveries possible. 
Printing spread ideas more quickly than
ever before.
(pages 511–512)
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Background to the Revolution (cont.)
The study of mathematics in the
Renaissance contributed to the scientific
achievements of the sixteenth and
seventeenth centuries. 
The great scientists of the day believed that
the secrets of nature were written in the
language of mathematics. 
These intellectuals–Copernicus, Kepler,
Galileo, Newton, and others–developed
new theories that became the foundation
of the Scientific Revolution.
(pages 511–512)
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A Revolution in Astronomy
Born in the second-century A.D., Ptolemy
was antiquity’s greatest astronomer. 
Medieval philosophers constructed a
geocentric (Earth is at the center) model
of the universe called the Ptolemaic
system. 
It is a series of concentric spheres with a
motionless Earth in the middle.
(pages 512–515)
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A Revolution in Astronomy (cont.)
According to Ptolemy, the planets are in
different, crystal-like spheres. 
They rotate, which accounts for the
movements of the heavenly bodies. 
The tenth sphere is the “prime mover,”
which moves itself and gives motion to the
other spheres. 
Beyond this is Heaven, where God and all
the saved souls reside.
(pages 512–515)
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A Revolution in Astronomy (cont.)
Nicholas Copernicus of Poland published
his famous work, On the Revolutions of
the Heavenly Spheres,
in 1543. 
He believed his heliocentric (with the Sun
in the center) system was more accurate
than the Ptolemaic system. 
Copernicus argued that all the planets
revolved around the sun, the Moon
revolved around Earth, and Earth rotated
on its axis.
(pages 512–515)
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A Revolution in Astronomy (cont.)
The German mathematician Johannes
Kepler also helped destroy the Ptolemaic
system. 
His observations confirmed that the Sun
was at the center of the universe, and he
tracked the elliptical orbits of the planets. 
Ptolemy had insisted that the orbits were
circular.
(pages 512–515)
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A Revolution in Astronomy (cont.)
The Italian scientist and mathematician
Galileo Galilei answered one of the
two remaining questions for the new
astronomy: What are the planets made
of? 
He was the first European to make regular
observations with a telescope. 
He saw mountains on the Moon and the four
moons orbiting Jupiter. 
Ptolemy had said the heavenly bodies were
pure orbs of light, but now it appeared
they were material.
(pages 512–515)
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A Revolution in Astronomy (cont.)
Galileo’s work began to make Europeans
aware of the new view of the universe. 
He got into trouble with the Catholic Church,
which ordered him to abandon the new
system because the Copernican
conception contradicted that of the
Church and the Bible. 
In the Copernican system, the heavens
were not spiritual but material, and God
was no longer in a specific place. 
Most astronomers believed the new
conception, however.
(pages 512–515)
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A Revolution in Astronomy (cont.)
The Englishman Isaac Newton responded to
the second question for the new
conception of the universe: What explains
motion in the universe? 
He was a mathematics professor at
Cambridge University. 
Newton published his views in Mathematical
Principles of Natural Philosophy, also
known as the Principia. 
He defined the three laws of motion in the
universe.
(pages 512–515)
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A Revolution in Astronomy (cont.)
Crucial to his view was the universal law of
gravitation: every object in the universe
is attracted to every other object by a
force called gravity. 
This explained why planetary bodies did not
go off in a straight line, but traveled in
elliptical orbits. 
Newton gave the world a picture of the
universe as a huge, regulated, uniform
machine. 
This picture dominated the modern
worldview until Einstein’s theory of
relativity.
(pages 512–515)
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Breakthroughs in Medicine
and Chemistry
In the Late Middle Ages, medicine was still
dominated by the teaching of the Greek
physician Galen (second century A.D.). 
His views about anatomy were often wrong
because he used animals, not people, for
dissection.
(page 515)
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Breakthroughs in Medicine
and Chemistry (cont.)
The new anatomy of the sixteenth century
was based on the work of Andreas
Vesalius, published in his On the Fabric
of the Human Body (1543). 
He reported his results from dissecting
human bodies as a professor of surgery
at the University of Padua, presenting an
accurate view of the individual organs and
general structure of the human body. 
He erroneously believed that the body had
two kinds of blood.
(page 515)
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Breakthroughs in Medicine
and Chemistry (cont.)
William Harvey’s On the Motion of the Heart
and Blood (1628) showed that the heart,
not the liver as Galen had thought, was
the beginning point of the blood’s
circulation. 
He also showed that the same blood runs
through veins and arteries and that the
blood makes a complete circuit through
the body. 
Harvey’s work was based on close
observation and experiment.
(page 515)
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Breakthroughs in Medicine
and Chemistry (cont.)
The work of Robert Boyle in chemistry was
also based on close observation and
experiment. 
He formulated Boyle’s Law about gases–
the volume of a gas varies with the
pressure exerted on it. 
In the eighteenth century, Antoine Lavoisier,
the founder of modern chemistry, invented
a system of naming the chemical
elements.
(page 515)
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Women and the Origins of
Modern Science
One of the most prominent female scientists
of the seventeenth century was Margaret
Cavendish. 
In works such as her Observations Upon
Experimental Philosophy, she criticized
the belief that humans, through science,
were the masters of nature.
(pages 515–516)
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Women and the Origins of
Modern Science (cont.)
In Germany, many women scientists were
astronomers. 
They often received training in family
observatories from their fathers or
husbands. 
Maria Winkelmann was the most famous;
she assisted her husband, the famous
Prussian astronomer Gottfried Kirch, and
discovered a comet.
(pages 515–516)
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Women and the Origins of
Modern Science (cont.)
Winkelmann was denied a post as assistant
astronomer at the Berlin Academy
because of her gender. 
In the view of most people of the
seventeenth century, science and
scholarship conflicted with the domestic
roles women were expected to fulfill.
(pages 515–516)
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Descartes and Reason
The work of the French philosopher René
Descartes strongly reflects the Western
view of humankind that came from the
Scientific Revolution. 
In his Discourse on Method (1637), he
asserts that he can rationally be sure of
only one thing–his own existence. 
He asserted he would accept only those
things his reason said were true.
(pages 516–517)
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Descartes and Reason (cont.)
Descartes asserted that while he could not
doubt the existence of his mind–“I think,
therefore I am”–he could doubt the
existence of the material world. 
He concluded that the material world and
the mental world were two different
realms. He separated mind and matter. 
This made matter something inert and
independent of the observer that could be
investigated by a detached rationality.
(pages 516–517)
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Descartes and Reason (cont.)
Descartes has been called the father of
modern rationalism. 
This system of thought is based on the idea
that reason is the chief source of
knowledge.
(pages 516–517)
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The Scientific Method
During the Scientific Revolution, people
were concerned about how they could
best understand the physical universe. 
They created the scientific method. 
The philosopher Francis Bacon was most
responsible for this method.
(page 517)
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The Scientific Method (cont.)
Bacon emphasized arriving at conclusions
about nature using inductive reasoning,
or making generalizations from particular
observations and experiments organized
to test hypotheses. 
He believed science was to give humankind
new discoveries and the power to serve
human purposes by conquering “nature in
action.” 
The control and domination of nature
became an important concern of science
and its accompanying technology.
(page 517)
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PHILOSOPHY IN THE AGE OF REASON
• Enlightenment sparked by scientific revolution of
1500s and 1600s
• Scientific discoveries of 1500s and 1600s changed the way
people looked at the world
• Natural law- rules that can be discovered through reason
• People started to believe that reason could solve social
problems as well as scientific problems= The Enlightenment
Left: Rene Descartes, French scientist of the late
Renaissance, stressed human reasoning in
understanding the world
Right: Immanuel Kant, German philosopher of
late Renaissance/early Enlightenment era, first to
speak of an “enlightenment”
OPPOSING VIEWS OF SOCIETY
• Thomas Hobbes and John Locke: conflicting views
• Hobbes: supported strong government (absolute monarchy),
thinks people are basically terrible, developed idea of a social
contract
• Locke: people basically good, had natural rights (life, liberty,
property), supported limited government
John Locke, whose
ideas inspired
revolution around
the world!
Of Hobbes and Locke,
which do you think had
more of an impact on
the American Revolution?
THE PHILOSOPHES
•
•
•
•
Montesquieu and the Separation of Powers
Freedom of Thought: Voltaire
Denis Diderot’s works: First Encyclopedia
The Social Contract: Jean-Jacques Rousseau
Left: Voltaire, French author of Candide
Right: Rousseau, author of The Social Contract
NEW ECONOMIC THINKING
• Mercantilism- government regulates prices and
tariffs to gain favorable balance of trade
• Laissez-faire economics= government should stay
out of the economy, free trade
• Adam Smith- argued for free market, said economy
runs on a system of supply and demand
• Smith also believed government should stay out of
economy, but did have a responsibility to protect
society
SOME THINGS TO THINK ABOUT:
• How did the Scientific Revolution that took
place during the Renaissance affect the
Enlightenment?
• How were the opinions of Hobbes and
Locke different, as they relate to
government’s role?
• What kinds of ideas or topics did the
Philosophers address in their writings?
• How did Rousseau’s and Voltaire’s beliefs
differ?
ENLIGHTENMENT IDEAS SPREAD
• New ideas challenge society
• People began to question “divine right” & class system
• Church & government censored writers, banned books
• Writers sometimes wrote fiction to expose corruption without
getting in trouble (Jonathan Swift, Voltaire, Montesquieu)
• Salons in women’s homes, Philosophers’ ideas spread
• Started with noblewomen hosting poetry readings in homes
• Middle class women began to do it as well
Re-creation of a French Salon from the
Museum of Decorative Arts in Lyon, France
NEW IDEAS REFLECTED IN LITERATURE
AND THE ARTS
• Movement of Baroque to Rococo
• Heavy, bright, grandiose to light, charming, and elegant
• Religious and military themed art to lighter topics
• Popular in spite of Philosophers dislike
Portrait of Carl Gustaf Wrangel
by David Klöcker Ehrenstrahl
Jean-Frédéric Schall Gardener in Straw Hat
Composers inspired by Enlightenment
• Introduction of what we call classical music
• Opera and ballet become popular all over Western Europe
• Bach, Handel, Haydn, Mozart
•
•
Drawing of Mozart
By Doris Stock, 1789
painting of
J.S. Bach
• New literary form: the Novel
• Growing middle class wanted stories in prose form
• Daniel Defoe, Robinson Crusoe
ENLIGHTENED DESPOTS LIKE THE NEW IDEAS
• Reform attempts by Frederick II
• Prussian king from 1740 to 1786, absolute monarch
• Allowed free press, religious toleration, reduced
torture use
• Catherine the Great’s response
• She studied works of Philosophers & admired them
• Religious toleration, reduction of torture, criticism
of serfdom
• More reforms by Joseph II
•
•
•
•
Traveled in disguise to get a feel for regular people
Like his mom(Maria Theresa), wanted to improve peasants’ lives
Religious equality for Protestants and Jews, abolition of serfdom
Many of his reforms were canceled after his death
LIVES OF THE MAJORITY
• Slow to change
• Early 1700’s
• Most people lived in country, didn’t hear new ideas
• Late 1700’s
• Enlightenment ideas started to spread to even the lower classes
• Some people didn’t want change, just wanted stable lives
• Others started revolutions to try to bring about social change
Three Peasants
Engraving by Albrecht Dürer
QUESTIONS TO THINK ABOUT:
• What did people opposed to the Enlightenment do to
stop these new ideas from spreading?
• Why did the philosophers want to share their ideas
with the rulers of Europe?
• Why was life so slow to change for many Europeans?
BIRTH OF THE AMERICAN REPUBLIC
• Britain as a global power
Location- island, large navy= good position to control trade
Few restrictions on trade= good for business
Won wars against France
gained control of Spanish slave trade (later abolished slavery in
their territories)
• 1707= union of England, Scotland, & Wales (Ireland added later)
• King George III
•
•
•
•
• 60 year reign started 1760
• Placed his friends in important positions to strengthen his power
• Got them to Parliament to gain support for his policies
• Many of his policies did not work out well for him
MID-1700S IN AMERICAN COLONIES
• String of colonies on east coast of what would become US, not
united or connected
• Britain applied mercantilist policies to force colonists to buy from
them and sell to them
• Navigation Acts were supposed to regulate trade and production,
(were not enforced)
• Smuggling was so common that the colonists didn’t see anything
wrong with it
• Colonists were more diverse than in Great Britain, social lines were
blurred
• Colonists set up their own assemblies and practiced open and free
discussion
COLONISTS UNHAPPY WITH THE SITUATION
• Various actions by Parliament and King George III were
making colonists mad (taxes)
• Colonists rebel
• March 1770= Boston Massacre
• 1773- Boston Tea Party
• First Continental Congress met in Philadelphia to discuss options
• Colonists declare their independence
• April 1775= Revolutionary War started in Massachusetts
• 1776= 2nd Continental Congress set up the Continental Army with
George Washington in charge
• Thomas Jefferson wrote Declaration of Independence,
full of Enlightenment ideas
• Life, liberty, pursuit of happiness Popular sovereignty=
government by consent of the governed
Adopted by Continental Congress on July 4, 1776
AMERICAN REVOLUTION
• Advantages:
• Britain: better trained soldiers, huge navy, natural resources,
support of about 1/3 of colonists and some Native tribes
• Colonists: home court advantage, strong leadership, dedicated
to winning their independence
• France supports the colonies
• 1777- Colonists won the Battle of Saratoga, France decided to join
(so did other nations)
• Washington held his troops together in dire circumstances
• Treaty of Paris ends the war
• 1781- French blockade of Chesapeake Bay forced British to
surrender (Yorktown)
• 1783- Treaty of Paris ended the war, forced Britain to recognize
the United States of America
A NEW CONSTITUTION
• Articles of Confederation
• Too weak, focused on states’ rights, not central gov’t
• 1787- framers met to write new constitution (Washington,
Madison, Franklin, etc.)
• Huge impact of Enlightenment ideas
• Took Montesquieu’s idea of separation of powers & checks and
balances
• Federal Republic- states within a nation, each with rights
• Government as social contract (Locke, Rousseau)
• elected president and legislature (could be replaced)
• Bill of Rights guaranteeing certain freedoms
• Became supreme law of the land in 1789 (over 235 years old!)
SYMBOL OF FREEDOM
• Our struggle for independence inspired revolutions
in Latin America and France
• Many other nations have constitutions that are
based on ours!
QUESTIONS TO THINK ABOUT:
• What Enlightenment ideas are found in the
Declaration of Independence?
• What advantages did the British have in the
American Revolution? What advantages did the
colonists have?
• What Enlightenment ideas are found in the
Constitution?
WORKS CITED:
• Ellis, E. G., & Esler, A. (2007).Prentice Hall world
history. Boston, Mass.: Pearson Prentice Hall.
• All photographs are from Wikimedia Commons and
are in public domain due to one of the following
reasons:
• Copyright expired due to age of the work
• Reproduction of a work already in public domain
• No copyright exists