The Scientific
Revolution
What Was the Scientific Revolution?
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A revolution in human understanding and knowledge about
the physical universe
17th century
Began with Kepler, Galileo
Ended with Newton
“Science” Before
the Scientific Revolution
• Based almost entirely
on reasoning
• Experimental method
or observation wasn’t
used at all
• Science in medieval
times
• Alchemy
• Astrology
A medieval alchemist
Factors Leading to
the Scientific Revolution
• Rise of
universities
• Contact with
non-Western
societies
• The
Renaissance
• Exploration
Rationalism
• Reason, not tradition, is the
source of all knowledge
• René Descartes (1596–1650)
• French philosopher and
mathematician
• Cogito ergo sum (“I think,
therefore, I am”)
• Deductive reasoning
René Descartes
The philosophy of rationalism holds that all knowledge comes
from reason. René Descartes was one of the most important
philosophers and mathematicians of his time; many regard him
as the father of modern rationalism. In Discourse on Method and
The Meditations, he reasoned that all of his prior knowledge was
subject to doubt because it was based on traditional beliefs
rather than on reason. He pondered what he could honestly say
he knew to be true, going so far as to doubt whether he was
awake or dreaming—or if he even existed. He then began to
reconstruct his world view: he knew that his thoughts existed,
which then suggested the existence of a thinking being—himself.
Descartes then came to his famous conclusion, “Cogito ergo
sum,” which means “I think, therefore, I am.”
Empiricism
• The belief that experience is
the only true source of
knowledge
• Roger Bacon
• Shift toward empiricism a
hallmark of the Scientific
Revolution
• Helped lead to the
development of the scientific
method
Roger Bacon
Francis Bacon and
the Scientific Method
• 1561–1626
• English philosopher and
empiricist
• Inductive reasoning
• Argued for experimental
methodology
English philosopher Sir Francis Bacon laid the theoretical
groundwork for what became known as the scientific method.
His ideas about science incorporated what is known as
inductive reasoning, which involves using concrete facts to
extrapolate broader conclusions. (Inductive reasoning is the
opposite of deductive reasoning.) Bacon argued that scientists
should work from the specific (observable data) to the general
(rules and theories based on that data). He believed that all
scientific research should rely on careful observation and
experimentation rather than simply relying on one’s own
thought and reasoning, as earlier scientific thinkers had. The
data obtained should then be recorded and analyzed according
to logic and reason, then used to produce a testable
hypothesis.
The Scientific Method
Science as a multiple-step process:
1. Scientists
identify a
problem
2. Form a
hypothesis
that can be
tested
3. Perform
experiments
to test the
hypothesis
4. Record
results of
experiments
5. Analyze
results of the
experiment to
form a
conclusion that
either proves
or disproves
the hypothesis
Roots of Scientific Thought: Aristotle
• 4th century BCE Greek
philosopher and scientist
• Wrote several scientific works
• His work laid the foundation for
scientific study through the
medieval era
• Gravity/Theory of falling objects
• Astronomy: Crystal spheres
Roots of Scientific Thought: Ptolemy
• 2nd century CE Greek
astronomer, mathematician,
and geographer
• The Almagest (Syntaxis)
• Geocentric (earth-centered)
model of the universe
• Motion of the planets
Models of the Universe:
Geocentric vs. Heliocentric
Geocentric: the Earth is at the
center of the universe; all
heavenly bodies move around
the Earth
Heliocentric: the Sun is at the
center of the universe; all
heavenly bodies move around
the Sun—including the Earth
Nicholas Copernicus (1473–1543)
• Polish astronomer and
mathematician
• Commentariolus (1514)
• Concerning the Revolutions
of the Celestial Spheres
(1543)
Tycho Brahe (1546–1601)
• Danish astronomer
• Amassed accurate
astronomical data
• Theorized a system
distinct from both the
Ptolemaic and
Copernican ones
• Argued that the Moon
and Sun revolve
around the Earth while
other planets revolve
around the Sun
Johannes Kepler (1571–1630)
• German astronomer and
mathematician
• Student of Tycho
• Didn’t agree with Tycho’s
interpretation of data
• Disagreed with Copernicus,
claiming that other bodies
moved in elliptical motion, as
opposed to circular motions
• Theorized three laws of
planetary motion using
Tycho’s data
Galileo Galilei (1564–1642)
• Italian mathematician,
astronomer
• “Father of Science”
• Telescopes and astronomical
discoveries
• Theory of falling objects;
disproved Aristotle
Galileo’s
telescopic
drawing of
the moon
Galileo vs. the Catholic Church
• The church
condemned
heliocentric
conceptions of
the universe
• The Roman
Inquisition
• Galileo’s trial
• Galileo recants,
put under house
arrest
19th-century depiction of Galileo before the Inquisition tribunal
Sir Isaac Newton (1642–1727)
• English astronomer,
physicist, and
mathematician
• Synthesized the works of
Copernicus, Kepler and
Galileo
• The Principia
Considered by many to be the greatest figure of the Scientific
Revolution, Newton synthesized the works of Copernicus, Kepler, and
Galileo in formulating his theories on gravity and motion. After
decades of research, he presented the foundation of these theories
(along with other observations concerning mathematics and
geometry) in the Principia, perhaps the most influential science book
ever written. The Principia presented a new view of the world, one
expressed in entirely mechanical terms, with Newton portraying the
universe as a large clock that operated by a consistent set of rules. The
book was well received by the academic community of Europe at the
time and his new world view became the accepted paradigm until the
atomic age.
Legend holds that Newton “discovered” gravity when an apple fell on
his head from a nearby tree, although many believed Newton—who
loved to tell stories—made the whole thing up.
The Significance of
the Scientific Revolution
• Abandonment of ancient and medieval systems
• Development of the scientific method
• The Enlightenment
Critical Thinking Questions to Answer
• Explain the reasons as to why the Scientific
Revolution occurred.
• Give two (2) examples as to how the Scientific
Revolution effects your every day life today. Explain.