Enlightenment
―The 17th
Century‖
―The Age of
Reason‖
The Scientific Revolution
16 th-17th century
•Printing presses introduced in 1480s
•Basic assumptions of scientific fields
overthrown
•Main fields astronomy, anatomy,
botany, physics, mathematics
•Confined to scientific communities,
texts in Latin
Medieval Sciences—Older Views
•Aristotelian physics: four elements –
earth, air, water and fire
•Ptolemaic view of universe - the
Earth was the center of the universe
•Medicine: four humours of the body
•Genetics: inherited learning
Essentially, this theory held that the human body was filled
with four basic substances, called four humours, or
•Philosophy: person think
humors, which are in balance when adeductiveis healthy. All
diseases and disabilities resulted from an excess or deficit of
one of these four humors. The four humors were identified
as black bile, yellow bile, phlegm, and blood
Johannes Kepler (1571-1630)
•Astronomia Nova “The New
Astronomy,” 1609
•Looking at recorded sightings of
Mars
•All planets moving in elliptical
orbits
Galileo Galilei (1564-1642)
•1609 telescope
•1632 Dialogues on the Two Chief
Systems of the World (forced by
Church to recant)
•Universe subject to
mathematical laws
•Nature inherently logical
Isaac Newton (1642-1727)
•Overhauled principles of
physics
•Principia Mathematica, 1687
•Three Laws of Motion,
Principles of inertia, gravity
Isaac Newton (1642-1727)
Newton’s Three Laws of Motion
I. Every object in a state of
uniform motion tends to
remain in that state of
motion unless an external II. The relationship between an
force is applied to it. object's mass m, its
acceleration a, and the applied
force F is F = ma.
III. For every action there is an
equal and opposite reaction.
John Locke (1632-1704)
•Father of modern psychology, sociology
•Essay Concerning Human Understanding
•Two Treatises on Government (1689) —
Natural rights
–all knowledge is derived by experience
•Letter Concerning Toleration (1689)
Enlightenment
―The 18th
Century‖
Philosophy of the Enlightenment
•“philosophes,” “Republic of
Letters”
•Stress on reason, optimism, civic
reform
•Religious tolerance and political
equality
•Faith in science and education
•Believed in improvement and
experimentation
•Secular and cosmopolitan
18 th Century Changes
•Stable food supply
•Industrial Revolution
(approx. 1750s-1850s)
•Commercial revolution
•Social mobility
•New strains on government
Science v. Religion
Belief in God based on reason •End to witch trials, ca. 1700
rather than revelation or the
teaching of any specific
religion. •Criticism of the French
A form of natural religion, Deism
originated in England in the
Monarchy and the French
early 17th century as a Church
rejection of orthodox
Christianity. Deists asserted •Deism
that reason could find evidence
of God in nature and that God
had created the world and then
left it to operate under the •Toleration, hatred of
natural laws he had devised.
superstition
Voltaire (1694-1778)
•Granddaddy of Enlightenment
•Defender of religious toleration
•Critic of French church and
state
•Favored enlightened
monarchies
Baron de Montesquieu (1689-1755)
•Spirit of the Laws, 1748 •Inspired American Constitution
•Balance of Powers theory •Admired British system,
critic of French
Jean-Jacques Rousseau (1712-1778)
Social Contract, 1762
•Theory of the “General Will”
•Civilization corrupting
influence
•Inspiration to French Revolution
in a democratic society the
state represents the
general will of the citizens,
and that in obeying its laws
each citizen is pursuing his
own real interest
Diderot and D’Albert’s Encyclopedie
•Literary compilation of
Enlightenment thought
•Published 1751-1772
•28 volumes with over 70,000 articles
“Enlightened Despots”
•Joseph II of Austria (1780-1790)
•Frederick II of Prussia (1740-1786)
•Catherine II of Russia (1762-1796)
•Reduced power of clergy, aristocrats
•Centralization, legal reform, education
Consequences of the Enlightenment
•Urban Reforms
•Educational reforms
•Abolition Movement
•Challenges to the Church
•Spur to Revolution: American,
French, Haitian