The Age of Reason

We begin our discussion with …….

The Scientific Revolution

The 17th Century and the

The “Age of Genius”

Why Study History of Science?

• Because it is a pure form of thought

• Because it affected philosophy, literature, and the arts

• Because it changed the ideas of religion and man’s relationship to the concept of God

• Because it was the basis for the development of democratic societies.

Overview

• No specific starting date

• Could be linked to Leonardo da Vinci – the Middle Ages was focused on alchemy

• Rediscovery of Aristotle

• Influence of the Byzantine and Muslim worlds (chemistry)

Rejection of Aristotle

• His scientific views of the universe were questioned.

• His observations were limited by the equipment of his day, but at least he based his conclusions on observation.

• Still wrong.

• Believed that the earth was the center of the universe.

Copernicus, 1473-1543

• Polish clergyman and astronomer

• He concludes that the sun was the center of the universe

• Therefore …G(g)od must reside in the sun

Copernicus’s Observatory

You Stand Here

Tycho Brahe, 1546-1601• Brilliant mathematician• Believed Copernicus wrong.

Argued that earth was center of the universe.

• But, his efforts proved the truth of Copernicus’ theory of the universe

• Unfortunately, his personal life interfered with his professional recognition

Johannes Kepler, 1571-1630

• Brahe’s assistant• Finished Brahe’s theory of

the ‘ellipse’• Developed laws of planetary

motion• But, training as a minister

led Kepler to believe God must reside in the Sun.

Kepler’s System

Galileo Galilei, 1564-1642

• Follows Kepler’s view of the Universe

• Improved the telescope and discovered Jupiter’s planets

• Author of Starry Messenger• Concludes that ‘our’ solar

system was part of a larger system

• Church condemned him• Permanent house arrest

Galileo - 2• Also concluded that the moon was NOT luminous but

made of earth-like substances (challenges conventional wisdom)

• But, greatest achievement was elaboration of the experimental method/physics based on precise measurements rather than metaphysical or logical principles

• Formulated LAW OF INERTIA – determined that rest is NOT the natural state of objects – the dropping of weights of ten and one pound from the Tower of Pisa (strike ground at the same time)

Experimental Method• The study of cause and effect• Involves the deliberate manipulation of one

variable, while trying to keep all other variables constant

• Experiments can be replicated• Experiment yields quantitative data

(numerical amounts of something)• Diminishes likelihood of chance being the

reason for the result of an experiment

Empiricism• Asserts that knowledge comes from experience

(How do we know things?)• Branch of Epistemology (a branch of philosophy

devoted to the theory of knowledge)• In science (as a method) it is argued that all

evidence must be observable by the senses (tabula rasa)

• Linked to rationalism a philosophical study supported by John Locke, Thomas Hobbes, and David Hume

Francis Bacon – The Man1561-1626

• Lawyer and member of House of Commons

• Distrusted by Elizabeth but a favorite of James I

• Becomes one of most powerful politicians

• 1620, Publishes Novum Organum

• Bribery charge ends career. Dies in 1626 – bad chicken.

Bacon - The Thinker

• Represents first real departure from 16th Century thought.

• Preferred inductive reasoning to Aristotelian deductive reasoning – supported experimentation.

• Argued that the function of science was the betterment of human society.

• And, that science should be applied to real situations rather just be a series of abstract ideas.

Bacon – The Dead

• Believed that snow (cold) could preserve meat (practical application of scientific thought)

• Purchased chicken (stuffed it with snow) – contracted pneumonia

• Ate the chicken as a means of restoring his health (may have poisoned himself)

• Died ……. Experiment is said to have killed him

The Scientific Method(as credited to Bacon)

• Observe the Universe• Develop an hypothesis that is consistent with

observation.• Use the hypothesis to set a prediction• Test the predictions with experiments or

further observations, and modify hypothesis.• Repeat last two steps until consistency is

achieved between hypothesis and predictions

Deductive ReasoningFrom General to Specific

• All men are mortal• Socrates is a man• Therefore, Socrates is mortal

Inductive Reasoning

From Specific to General

Blaise Pascal• French mathematician, physicist, religious thinker

• Applied science (mechanical calculator), fluids, pressure, vacuum

• Founder of Probability Theory - influences study of economics

• Also, develops Projection Geometry – formalized perspective for artists

• Jansenism (the very conservative Catholic sect)1623-1662

Pascal’s Triangle provides

a visual explanation of

binomial coefficients –

critical to developing

probability

Renee Descartes, 1596-1650

• Poor of health, but brilliant• Linked to math and philosophy• Lawyer/soldier/teacher• Used deductive method to

explain math• Developed Analytical Geometry • Fascinated by optics• Died of pneumonia from drafty

room while tutoring royalty.

Descartes – The Philosopher

Cartesian Dualism“I think, therefore I am”

• Thinking proved existence, but nothing was true until it was proven true

• Descartes believed that there two distinctive elements, mind and matter.

• There is confusion over how the mind and matter are to interact.

• Descartes ultimately believes that God will provide the answer.

But – Descartes is ultimately proven wrong

Descartes metaphysical arguments are wrong …

However, he introduces mechanical or mathematical interpretations for phenomena, that allows scientists to move away from the reliance on spiritual interpretations of the past.

Descartes Link to the The Enlightenment

• All people can reason

• Special training is not necessary for reasoning.

• Argues for egalitarian society (basis of Enlightenment)

The Physical Sciences

Robert Hooke, 1635-1703The Microscope

Hooke • English natural philosopher/architect/surveyor• ‘Father of Microscopy’ and coined the term ‘cell’

to describe a basic unit of life• Argued with Newton (Newton, as president of

the Royal Society attempted to discredit Hooke)• Credited with ‘law of elasticity’ that permitted the

development of the first portable timepiece (watch)

• Worked with Christopher Wren (great architect)

Carl Linne 1707-1778

Classification of Species

Chemistry

Founders of European Chemistry

Henry Cavendish Hydrogen

Joseph PriestlyOxygen

Robert Boyle

• Father of Modern Chemistry• First to do controlled

experiments with a research group and to publish results.

• Helped found the Royal Society. (Refused the presidency of the group because the oath violated his religious beliefs)

• Created the vacuum pump• Credited with Boyle’s Law

(deals with the pressure of gas in a closed system)

• First to use term ‘chemical analysis’

14th child of Britain's wealthiest individual

1627-1691

Mechanical Developments

• Denis Papin - the steam digester (forerunner to the steam engine)

• Abraham Darby I – development of coke (critical to production of high-grade iron in a blast furnace)

• Otto von Guericke (1672) first generated electricity using a machine and Stephen Gray (1729) transmitted electricity

However,Descartes prepares the

scientific community for Isaac Newton

Isaac Newton, 1642 - 1727

• One of the foremost intellects of all time

• Major work was Principia• Served in government• Father of Calculus• Determined the nature of

gravity. Determined the force necessary to keep the moon in orbit.

• Never determined the cause of gravity.

Royal Society for the

Improvementof

Natural Knowledge

British Royal Academy

• Founded in 1660 (Charles II) – first of its kind in Western world

• Funded by British government

• Fellows of the Royal Society are awarded as an honor for life

• Dedicated to the free flow of information and communication in the sciences.

Biologyand

Medicine

WilliamHarvey

• English physician – trained in Italy

• Personal physician to James I and Charles I

• Earlier models suggested that veins were not connected

• First described the circulation system and the heart as a pump

• Did not affect medical practice – blood letting was still common procedure 1578-1657

Andreas Vesalius

• Belgian (Flemish), studied in Paris

• ‘Father of Surgery’• Author of early book on human

anatomy – accomplished by dissection

• Considered a great teacher (brought students close to the table)

• Leader in treatment of battlefield wounds

• Moved medicine into modern era1514-1564

A Medical Timeline• 1667 – First blood transfusion (lamb to boy, a

gentle lamb to quiet a disturbed youth) A 1490s effort to save the life of Pope Innocent VIII was unsuccessful.

• 1682 – Bacteria discovered• 1714 – First fine point syringe• 1717 – First inoculation against smallpox

(1796 – Edward Jenner is successful) • 1728 – Dentistry is recognized as a profession

Church Opposition …Sees a threat to belief systems

(new ‘religions’ and encouragement to question tradition)

Diesm• Observation of the natural world and reason

determine that the universe was created by a ‘supreme being’

• No need for organized religion or religious authority

• Rejects prophecy and miracles• Rejects concept of divine intervention in human

affairs – establishes the ‘Watchmaker’ theory of religion (Boyle and Descartes)

• Gains wide popularity during the Enlightenment

Skepticism

• Philosophical – examine knowledge and perceptions to determine truth

• Religious/Scientific – examine extraordinary claims and seek to disprove them using scientific method

• Empiricism – knowledge arises from experience …

• Link to Enlightenment ….

Consequencesof Scientific Study

• Creation of an international scientific community; scholars could engage in discourse about theories and ideas, thus expanding knowledge.

• The modern scientific method• Applied science• Major impact on how people think and believe• Organization of knowledge in every aspect of

existence

and ….A Link To The Enlightenment

• Belief that humans have the potential for progress

• That science can help make sense of the world• That laws of human society could be

understood through the use of the scientific methods

• That real reform of society can only occur through the acquisition of knowledge, and

• That human institutions can be perfected through reason