The “New Science” of the Seventeenth Century

From natural philosophy

to modern science

Revolution or Evolution?• Historians have long challenged the idea

of a single “Scientific Revolution”

• Most scholars see agree that the “new science” of the seventeenth century was the culmination of centuries of advances

• Still, it is impossible to deny that the seventeenth century witnessed an increase in knowledge, new methods, and growth of the scientific community

A paradigm shift?• In his pioneering 1962

work Kuhn argued that the Scientific Revolution represented a paradigm shift that allowed certain ideas to become “thinkable” – not just an inevitable outcome of the progress of science

Medieval Universities• In the Middle Ages, natural philosophers

saw nature as a book in which they could read the mind of God

• Thomas Aquinas had presented an ordered world which reflected the divine order of God

• Medieval science “stood on the shoulders of giants” and scholars believed that all human knowledge had been understood by the ancient philosophers

Humanism and science• Many of the most famous humanists were

not interested in ‘science’ per se – they were interested in eloquence and morals

• But their interest in classical antiquity also pushed them to study the texts of ancient philosophers and mathematicians more closely.

• Neoplatonism was influential, as was the mechanistic theories of the Greek physicist Archimedes

New methods of observation• Renaissance artists were keen on

observation and description of the world around them ‘the mind of a painter should be like a mirror’

• For example, Da Vinci encourages dissection of corpses; renaissance art and architecture works with geometry and light

• These artists develop tools and formulas that can be extended to the study of astronomy

Astronomy• Aristotle and Ptolemy were the two main

sources for astronomy – they supported the long-held idea that the sun, stars, and the planets revolved around the earth

• The earth-centred universe was important for a couple of reasons:– It was the foundation of theological

conceptions of the universe– On a more practical level, it was how the year

was measured and the calendar was devised

The Ptolmaic universe• Aristotle had described an orderly cosmos• Things could change on earth, but the

heavens were thought to be unchanging, moving in perfect circles

• People had noticed inconsistencies in this theory – simple observation of planets showed this

• The mathematician Ptolemy (85-165) had developed complicated formulas to explain the irregularities

Ptolemy’s universe

Nicholas Copernicus (1473-1543)• Based on mathematical formulas, he

suggested that the earth and the planets revolved around the sun

• This would solve many of the problems with the calendar and avoid the complicated and mathematical formulas upon which Ptolemy’s system relied

• Copernicus did not want to challenge the church or ancient authorities

• He did not base his theory on observation

Copernicus

• Copernicus did not have a system of physics that could explain an earth in motion

• His mathematical ideas were published just before his death in On the Revolution of the Heavenly Spheres (1543)

Observing the heavens

• The work of Copernicus was all theoretical• It took time for others to take up his

theories and to prove them by observation• Tycho Brahe was a Danish nobleman who

devoted much of his life and resources to observing the movement of the heavens

• An example of his audacity is that he discovered a new star – an impossibility according to Aristotle.

Tycho Brahe (1546-1601)• Brahe was not convinced

by Copernicus – he believed the planets orbited the sun and that the whole system revolved around the earth, which was less challenging to contemporary ideas.

• His observations were very accurate and formed the basis of Kepler’s work

Johannes Kepler (1571-1630)• He did support the

Copernican view of the universe – with modifications

• First, he argued that planets revolved around the sun in elliptical orbits – not the perfect circles that both Ptolemy and Copernicus relied on

Kepler

• His ‘Second law’ was that planets moved at different speeds depending upon their distance from the sun – not uniform speed as Copernicus had suggested

• Most scientists in the 17th century rejected this idea – but it was an integral part of the development of Newton’s laws of gravity.

Galileo Galilei (1564-1642)• Galileo not only set out

to prove Copernicus’ theory through observation, but also argued for a new partnership between religion and science

• Ultimately, his argument was unsuccessful

Tools of science: the telescope

• In 1610, Galileo procured a telescope and began making observations of the heavens

• He observed moons orbiting Jupiter – which proved that the earth was not the only planet with objects in orbit around it

• Initially, he received patronage for his work, but it quickly brought him into conflict with the church

Robert Bellarmine (1542-1621)• Cardinal Bellarmine, one of

the leading Jesuit scholars, led the attack on Galileo

• Argued against Copernicanism and had his work included in the Index of Prohibited Books

• In effect, he managed to silence Galileo for the time being

Galileo’s Trial• After Bellarmine’s death, Galileo again

began to promote helicentrism• The church charged him with heresy, both

for promoting Copernicus and for offending his patron Maffeo Barberini, who had become Pope Urban VII

• He was threatened with excommunication and death and he recanted his beliefs

• In secret, he continued to work on his theories until his death

Method in philosophy• Natural philosophers in the 16th century

lacked a common set of principles and goals for undertaking scientific experiments

• They believed that Aristotelian philosophy was no longer suitable arguing that the “moderns” should go beyond the ancients

• Philosophers like Descartes and Bacon attempt to come up with a method to discover truth using natural reason

Francis Bacon (1561-1626)• Advocates an empirical

approach to studying the world – based on observation through the senses – inductive reasoning

• Advocates for researchers to share their observations

• His work Novum Organum (1620) outlines his views

René Descartes (1596-1650)• Advocated the use of

deductive reasoning to come to truth – speculation could offer a solid basis for truth

• Promotes ‘universal doubt’ as a method to discover truth

• His principles are based on logic and math

The Scientific method• Bacon relies on sense perception and

observation (induction), while Descartes relies on logic and mathematics (deduction)

• Bacon and Descartes agreed about two things:– Don’t rely on ancient authorities – start fresh– Science should be defined by utility

Mechanistic world-view• Both Bacon and Descartes are

mechanistic – they think of human beings as machines with rational minds

• In England, scientists follow Bacon’s empiricism – conducting experiments and observations

• In France, scientists follow Descartes’ logical speculation – emphasizing mathematical and logical proofs

• In both countries, scientific societies were formed to share research and conclusions

Isaac Newton (1642-1727)• Newton shared an

interest in observation with Bacon and in mathematics with Descartes

• Newton attempted to break out of the mechanistic world view to describe forces – like gravity

Revolution in physics

• Newton’s major achievements include:– Three laws of motion– Law of universal gravitation– Invention of calculus– These three achievements were so profound

because they had practical applications in a number of areas – from understanding the nature of the universe to making parts for machinery

Conclusion• What makes the scientific revolution seem

distinctly modern is that it acknowledges that there are things about the world that can be known

• The ancients, like Plato and Aristotle, start to take a secondary place to observation through the senses and mental reflection

• Perhaps more importantly, a pan-European group of scientists emerges who share their results with each other