1. The Scientific Revolution
The Scientific Revolution marked the beginning of a dramatic shift in how people viewed the world. The medieval and early modern European outlook had been dominated by religion. As a result of this revolution, many came to see the world predominantly in secular and scientific ways. In the short term, the Scientific Revolution set the stage for the Enlightenment; its long-term repercussions can still be felt today.

2. What Was the Scientific Revolution?
A revolution in human understanding and knowledge about the physical universe
17th century
Began with Kepler, Galileo
Ended with Newton
The Scientific Revolution is generally viewed as a 17th-century phenomenon. Most historians consider it to have started with the astronomical discoveries of individuals like Kepler and Galileo and ended with the publication of Newton’s major works. We will describe these “bookends” of the Scientific Revolution in greater detail later in this discussion.

3. “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
More than anything else, science is a habit of mind. It involves using reason, observation, testing, and systematic thought to uncover truths about the world and about people, animals, and things in the world. “Science” as we know it today didn’t really exist before the Scientific Revolution. Instead, scientists in ancient and medieval times were really philosophers who drew conclusions based on deductive reasoning; they rarely conducted practical experiments.
Much of what was considered “science” in medieval times had very little basis in fact and drew more from superstition and religious belief. Similar in many ways to chemistry, alchemy aimed to develop potions that would do things such as change iron into gold, cure all disease, or bestow immortality. Astrology was based on the concept that the positions and conditions of celestial bodies could influence human existence, both positively and negatively. Practitioners of astrology would often claim that human suffering (including sickness) could be explained by the position of the stars.
A medieval alchemist

4. Factors Leading to the Scientific Revolution
Rise of universities
Contact with non-Western societies
The Renaissance
Exploration
A number of factors helped lay the groundwork for the Scientific Revolution:
The first universities appeared during the Middle Ages. Although universities initially focused primarily on topics like law and philosophy, they gradually expanded their offerings and came to establish professorships in areas such as mathematics, astronomy, medicine, and other science-related disciplines. Universities brought together leading scientific minds, encouraged intellectual debate, and sparked interest in research and discovery.
Muslim scholars of the Middle Ages made several important mathematical and scientific discoveries. During the 12th and 13th centuries, both the Crusades and the expansion of trade networks brought Europeans into greater contact with Muslim societies. Both cultural and intellectual exchanges occurred; this infusion of new ideas helped improve Europeans’ understanding of mathematical principles in particular and of science in general.
As the Renaissance dawned and inspired advances in art and literature, educated Europeans began to look beyond the church and the Bible for knowledge and truth. In addition to serving as patrons of the arts, wealthy families such as the Medicis in Italy also supported scientific research.
The Age of Exploration also provided impetus for the Scientific Revolution. The challenges of navigating across the Atlantic Ocean and around Africa motivated advances in mathematics, astronomy, and cartography (mapping). European monarchs interested in expanding their overseas empires (including King John of Portugal, King Ferdinand and Queen Isabella of Spain, and Queen Elizabeth I and King Charles II of England) provided funding and/or support for scientific research.

5. 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
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.”
Descartes’ conclusions were based on deductive reasoning, which involves using a general principle to draw conclusions about a specific instance. For example, once he had come up with Cogito ergo sum, he used it to draw a further conclusion: because the mind “cannot be doubted but the body and material world can, the two must be radically different.” In other words, Descartes drew a clear distinction between mind and matter—an idea that helped break down superstitions that had influenced science in the medieval era.
René Descartes

6. 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.”

7. 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
The philosophy of empiricism holds that the only real way to acquire knowledge is through experience—that is to say, through observation. Empiricism stands in opposition to rationalism, which holds that knowledge could be acquired through the exercise of one’s reason alone. Some of the first writings on empiricism came in the 13th century from Roger Bacon, an English scholar. In his work Opus Maius, Bacon wrote, “There are two modes of knowledge, through argument and experience. ‘Argument’ brings conclusions and compels us to concede them, but it does not cause certainty nor remove doubt in order that the mind may remain at rest in truth, unless this is provided by experience.”
One of the hallmarks of the Scientific Revolution was the new focus on empiricism. Empiricism also helped lead to the development of the scientific method.
Roger Bacon

8. 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.

9. 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.

10. Science as a multiple-step process:
The Scientific Method
Science as a multiple-step process:
Scientists identify a problem
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
The textbook discusses a five step process.

11. 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
Aristotle was a Greek philosopher and scientist who lived in the 4th century BCE. He is considered one of the most influential philosophers in Western thought. Although much of his work concerned topics like politics and ethics, he also wrote many works concerning biology, zoology, and physics. His works provided the theoretical foundation for science for centuries to come. Although Aristotle came up with many brilliant insights into philosophy and government, in science he relied on reason rather than empirical evidence and did not conduct experiments; consequently, many of his conclusions were incorrect. For example, he hypothesized that gravity occurred because objects were attracted to the Earth’s core, and theorized that heavier objects would fall to earth more quickly than lighter ones. He also came up with a theory of astronomy which hypothesized that a motionless Earth lay at the center of the universe surrounded by concentric crystal spheres. One sphere held the moon, another the sun, others held each of the five known planets at the time, and the last held what the ancient Greeks referred to as the “fixed stars.”

12. 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
Ptolemy, another ancient Greek, was an influential mathematician, astronomer, and geographer who lived in the 2nd century CE. Around 150, he wrote the Almagest (also known as the Syntaxis), his most important work. In it, he provided a comprehensive overview of mathematical astronomy and formalized the concept of a geocentric (meaning “earth-centered”) model of the universe. He also offered detailed mathematical rules describing the motion of each of the planets.

13. 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
Derived from the Greek words “geo” (meaning earth) and “centron” (meaning center), the geocentric view were generally the view pushed by Aristotle and Ptolemy (see above). Geocentricism was officially endorsed by the Catholic Church and taught at religious schools and universities.
Derived from the Greek works “helios” (meaning sun) and “centron” (meaning center), the heliocentric conception was the most prominent theory pushed during the Scientific Revolution.

14. Nicholas Copernicus (1473–1543)
Polish astronomer and mathematician
Commentariolus (1514)
Concerning the Revolutions of the Celestial Spheres (1543)
In 1514, Copernicus wrote Commentariolus, a short, handwritten notebook of observations in which he laid out the foundations of his heliocentric theories. He did not sign his name to Commentariolus and distributed it only to a few friends, fearing that the controversial nature of his thoughts might provoke the anger of the Catholic Church. The following year, however, he began to write Concerning the Revolutions of the Celestial Spheres, in which he expanded on the heliocentric model he had proposed in Commentariolus. He worked on the book for the rest of his life; it was finally published just before his death in Despite the importance of Copernicus’ work, at the time his theories did little more than spark debate among scientific thinkers and had little initial impact outside of academic circles. His ideas would provide the foundation for the revolutionary work of later scientists.

15. 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
Tycho Brahe is more often referred to by his first name, not his last. He made a name for himself as an astronomy lecturer at the University of Copenhagen and in the late 1570s came to the attention to one of the great “enlightened monarchs,” Frederick II of Prussia. Frederick offered to provide the funds for Tycho to construct an observatory; built on an island near Copenhagen, Tycho’s Uraniburg observatory became regarded as the finest in Europe. At Uraniburg, Tycho designed and built several new astronomical instruments and used them to create some of the most accurate star charts of the time. He also owned both a paper mill and a printing press and self-published a number of his works, including The Dream, considered one of the first works of science fiction.
Tycho is important largely because he gathered a huge amount of astronomical data with unprecedented accuracy. He also came up with a theory of the heavens that offered an alternative to both the Ptolemaic and Copernican models, arguing that the Sun and the Moon revolved around Earth while other planets in the solar system revolved around the Sun. The latter assertion helped answer observation-based criticisms about earlier conceptions of the Universe without requiring a heliocentric model of the universe.

16. 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
Kepler originally studied theology but ended up as a professor of mathematics. As a student of Tycho, he studied both his teacher’s works as well as the writings of Copernicus. Kepler claimed that while Tycho’s data was correct, his interpretations of the data were incorrect; he further argued that Tycho’s data actually proved Copernicus correct.
Kepler also took issue with Copernicus’ claim that astronomical bodies moved in circles, asserting instead that they moved in elliptical patterns—an assertion that later proved correct. Kepler used Tycho’s data and his own observations to develop three laws of planetary motion and proved the core of heliocentric theory.

17. Galileo Galilei (1564–1642) Italian mathematician, astronomer
“Father of Science”
Telescopes and astronomical discoveries
Theory of falling objects; disproved Aristotle
Galileo is considered the father of modern physics, astronomy, and more generally the “Father of Science.” He created several different telescopes (improving the power of with each successive model) and used them to record extraordinary amounts of data. His interpretations of the data yielded some remarkable discoveries, including:
Stars were farther away than planets
There were mountains on the Moon
Jupiter has four moons
Saturn has rings
He eventually compiled and published his observations in a 1610 work titled The Starry Messenger. Galileo’s work, combined with the previous discoveries of Copernicus and Kepler, left little doubt among the mainstream scientific community that the Ptolemaic model of the universe was incorrect.
He also conducted a famous experiment in which he showed Aristotle had been mistaken in his assumption that objects of different weights falling at different rates of speed. Having proven this, he went on to establish an explanation of speed and motion. Galileo also created a thermometer, which permitted more accurate data collection.
Galileo’s telescopic drawing of the moon

18. 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
Galileo’s scientific observations proving that the Earth wasn’t at the center of the universe had vast religious implications. The Catholic Church perceived heliocentric theories as questioning long-held doctrinal teachings about the nature of the heavens. The Church ultimately found it easier to condemn the heliocentric view of the universe as “foolish” and “formally heretical” rather than figure out how it could fit into a religious framework.
In 1630, Galileo had received conditional permission from the Vatican to publish the Dialogue. Months after its first printing in 1632, however, Pope Urban VIII ordered a halt to distribution of the book and created a special commission to investigate whether the work was heretical. The commission recommended that Galileo’s case be referred to the Roman Inquisition, which ruled on cases of suspected heresy. Galileo’s trial before the Inquisition tribunal began in April 1633.
Galileo defended himself by arguing that while the Church had earlier told him not to hold or believe Copernican theories, it had never told him not to teach about them. The tribunal threatened Galileo with torture, imprisonment, and even burning at the stake if he refused to recant his views; eventually, he succumbed. Sentenced to house arrest due to his fragile health and advanced age, Galileo was forced to recite prayers every day and wasn’t supposed to be allowed visitors, though neither of these were well enforced. In spite of the toll it had taken on him both mentally and physically, Galileo’s battle with the Church didn’t dampen his intellectual curiosity, and he continued to write, research, and publish. The trial had a chilling effect on scientists practicing in Italy and pushed the focus of mainstream science north to places like England and France. It also highlighted the tensions between religion and science.
19th-century depiction of Galileo before the Inquisition tribunal

19. 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.

20. 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.

21. The Significance of the Scientific Revolution
Abandonment of ancient and medieval systems
Development of the scientific method
The Enlightenment
The most obvious result of the Scientific Revolution was the rejection of ancient and medieval systems in science, astronomy, and medicine. After the Scientific Revolution, many previously accepted theories had been completely disproved or discarded.
The methods developed during the Scientific Revolution would fuel discoveries for centuries to come. Basing science more firmly in empiricism made conclusions more consistent, reproducible, and accurate.
The Scientific Revolution also set the stage for the Enlightenment. Like the pioneers of the Scientific Revolution, Enlightenment thinkers strove to make conclusions based on observation, logic, and reason, rather than on faith.
Though the Scientific Revolution had little immediate impact on society as a whole, its long-term repercussions can still be felt today. Perhaps more important than the specific advances in science, the Revolution represented a shift in worldview: it was an intellectual revolution that changed the way that people saw and interpreted the world around them.

22. 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.