The Church and Science in the Seventeenth Century Ann T. Orlando 30 April 2007

Outline Background Background Aristotelian Science Aristotelian Science Galileo Affair Galileo Affair Example: Controversy over vacuums Example: Controversy over vacuums Conclusion: The Enlightenment Conclusion: The Enlightenment

Aristotelian Physics Aristotle ( BC) was an empiricist; knowledge through the sense Aristotle ( BC) was an empiricist; knowledge through the sense But also believed that there was a well defined structure to universe, But also believed that there was a well defined structure to universe, Structure could be known Structure could be known All substances made of matter and form All substances made of matter and form Matter made of four elements: earth, air, fine, water in sublunar region; unchanging ether above the moon Matter made of four elements: earth, air, fine, water in sublunar region; unchanging ether above the moon The cosmos is eternal, filled with elements The cosmos is eternal, filled with elements All changes in substances governed by four causes: material, formal, efficient (violent) and final All changes in substances governed by four causes: material, formal, efficient (violent) and final Motion is defined as being inversely proportional to density of medium through which a body travels Motion is defined as being inversely proportional to density of medium through which a body travels

The Problem with a Void Aristotle’s conception of matter and form was opposed to Epicurean motion of atoms and voids Aristotle’s conception of matter and form was opposed to Epicurean motion of atoms and voids Aristotle had been strongly opposed to the concept of a void in nature Aristotle had been strongly opposed to the concept of a void in nature Argued that if a void existed it was ‘something’ but two things could not occupy the same space; so a void could not exist Argued that if a void existed it was ‘something’ but two things could not occupy the same space; so a void could not exist Another important Aristotelian argument against the void was based on his definition of motion Another important Aristotelian argument against the void was based on his definition of motion

Church and Physics in the Thirteenth through the Seventeenth Century Just as scholastic theology relied on Aristotle, so did medieval physics Just as scholastic theology relied on Aristotle, so did medieval physics Condemnations of 1277 emphasized basic Aristotelian physics Condemnations of 1277 emphasized basic Aristotelian physics No voids No voids Earth-centered cosmology Earth-centered cosmology All substances composed of matter and form All substances composed of matter and form No change to celestial spheres beyond the moon No change to celestial spheres beyond the moon Velocity is inversely proportional to density of medium through which an object moves; therefore a vacuum is impossible Velocity is inversely proportional to density of medium through which an object moves; therefore a vacuum is impossible

New Observations in Sixteenth and Seventeenth Centuries Telescope allows observations of heavens that calls older physics into question Telescope allows observations of heavens that calls older physics into question Reveals changes in sun, moons of Jupiter Reveals changes in sun, moons of Jupiter Earth revolves around the sun Earth revolves around the sun New understanding of velocity New understanding of velocity Dropped balls fall at same rate, regardless of weight Dropped balls fall at same rate, regardless of weight Velocity of a body not defined by resistance of medium Velocity of a body not defined by resistance of medium Experiments with gasses leads to speculation about atomic theory of matter, not matter and form Experiments with gasses leads to speculation about atomic theory of matter, not matter and form

Galileo Affair Galileo ( ) controversy; Church silences Galileo because of his support of Copernicus Galileo ( ) controversy; Church silences Galileo because of his support of Copernicus Actually, Galileo committed the cardinal sin of making fun of his patron (research sponsor) Actually, Galileo committed the cardinal sin of making fun of his patron (research sponsor) Censured in 1633 Censured in 1633 But the Jesuits also supported Kepler ( ) against Protestant attackers But the Jesuits also supported Kepler ( ) against Protestant attackers Part of Robert Bellarmine’s ( ) argument against Galileo was that his circular orbits were not consistent with observations; Part of Robert Bellarmine’s ( ) argument against Galileo was that his circular orbits were not consistent with observations; Epicycles explained astronomical observations better than circular orbits Epicycles explained astronomical observations better than circular orbits Okay to use heliocentric system to aid calculations Okay to use heliocentric system to aid calculations

Philosophical Developments During the 17 th C The question of the 17 th C: how do we know (epistemology) The question of the 17 th C: how do we know (epistemology) Or maybe we can’t know; rise of modern skepticism Or maybe we can’t know; rise of modern skepticism Rationalist: Knowledge is from ideas Rationalist: Knowledge is from ideas Rene Descartes ( ) Rene Descartes ( ) Blaise Pascal ( ) Blaise Pascal ( ) Gottfried Leibniz ( ) Gottfried Leibniz ( ) Empiricists: Knowledge is from senses Empiricists: Knowledge is from senses Francis Bacon ( ) Francis Bacon ( ) Pierre Gassendi ( ) Pierre Gassendi ( ) Thomas Hobbes ( ) Thomas Hobbes ( ) John Locke ( ) John Locke ( )

17 th C Philosophy: Rationalists Rationalist: Knowledge is from ideas Rationalist: Knowledge is from ideas Rene Descartes ( ) Rene Descartes ( ) Mathematician and founder of analytic geometry and algebra Mathematician and founder of analytic geometry and algebra “I think, therefore I am” “I think, therefore I am” Dualistic approach to mind and body Dualistic approach to mind and body Blaise Pascal ( ) Blaise Pascal ( ) Mathematician and founder of laws of probability Mathematician and founder of laws of probability Member of Jansenists: heretical Catholic group that was very Augustinian Member of Jansenists: heretical Catholic group that was very Augustinian Pascal’s Wager on the existence of God Pascal’s Wager on the existence of God Gottfried Leibniz ( ) Gottfried Leibniz ( ) Mathematician and founder of calculus Mathematician and founder of calculus Because God is all good, this must be the best of all possible worlds Because God is all good, this must be the best of all possible worlds Complex metaphysics; many similarities to Stoicism Complex metaphysics; many similarities to Stoicism

17 th C Philosophy: Empiricists Empiricists: Knowledge is from senses Empiricists: Knowledge is from senses Francis Bacon ( ) Francis Bacon ( ) The modern idea of technological “progress” (in the sense of a steady, cumulative, historical advance in applied scientific knowledge) began with Bacon’s The Advancement of Learning The modern idea of technological “progress” (in the sense of a steady, cumulative, historical advance in applied scientific knowledge) began with Bacon’s The Advancement of Learning Champions inductive logic based upon extensive observation; proceed from particular to general Champions inductive logic based upon extensive observation; proceed from particular to general Thomas Hobbes ( ) Thomas Hobbes ( ) Atheist and materialist: does not accept natural law of God Atheist and materialist: does not accept natural law of God Impressed by current scientific advances Impressed by current scientific advances Very pessimistic about human nature: social contract with threats of punishments only way to control behavior Very pessimistic about human nature: social contract with threats of punishments only way to control behavior Pierre Gassendi ( ) Pierre Gassendi ( )

Background on Pierre Gassendi Born in Champtercier, France 1592 died 1655 in Paris Born in Champtercier, France 1592 died 1655 in Paris One of the most famous physicists of his day One of the most famous physicists of his day Some beliefs out of step with other natural philosophers Some beliefs out of step with other natural philosophers Tried to build a philosophical system around Epicureanism Tried to build a philosophical system around Epicureanism Reject mathematics as best way to describe nature; instead relied on words and an analysis of all past words spoken on any topic in combination with experiments Reject mathematics as best way to describe nature; instead relied on words and an analysis of all past words spoken on any topic in combination with experiments Tried to maintain unity of physics and faith Tried to maintain unity of physics and faith

Gassendi and Christian Classics Tried to reconcile physics with Bible, primarily through commentaries on Genesis, with Epicurean physics and ethics Tried to reconcile physics with Bible, primarily through commentaries on Genesis, with Epicurean physics and ethics If later Christian philosophers could ‘rehabilitate’ Aristotle, Gassendi should be allowed to rehabilitate Epicurus: If later Christian philosophers could ‘rehabilitate’ Aristotle, Gassendi should be allowed to rehabilitate Epicurus: “The early Church Fathers were particularly opposed to Aristotle and his philosophy, and they displayed extreme animosity against the followers of Aristotle. But when some philosophers were converted to the faith, they began to set aside the more serious errors of Aristotle. What remained of Aristotelian philosophy was then accommodated to religion so successfully that it was no longer suspect and finally became the handmaid ministering to religion. Therefore I say, just as it was possible in the case of Aristotelian philosophy, which is now taught publicly, so it is possible with other philosophies such as the Stoic and Epicurean. All of them have much that is of value and worthy of being learned once the errors are eliminated and refuted in the same way as the very grave errors of Aristotle were refuted.” Syntagma Philosophicum, Opera Omnia 1:5. “The early Church Fathers were particularly opposed to Aristotle and his philosophy, and they displayed extreme animosity against the followers of Aristotle. But when some philosophers were converted to the faith, they began to set aside the more serious errors of Aristotle. What remained of Aristotelian philosophy was then accommodated to religion so successfully that it was no longer suspect and finally became the handmaid ministering to religion. Therefore I say, just as it was possible in the case of Aristotelian philosophy, which is now taught publicly, so it is possible with other philosophies such as the Stoic and Epicurean. All of them have much that is of value and worthy of being learned once the errors are eliminated and refuted in the same way as the very grave errors of Aristotle were refuted.” Syntagma Philosophicum, Opera Omnia 1:5.

Gassendi’s Evidence for a Void Empirical Evidence Empirical Evidence Chemical Chemical Barometric Barometric Dynamic Dynamic Historical Christian Evidence Historical Christian Evidence Angels Angels Nemesius Nemesius Irenaeus Irenaeus

Gassendi and the Void Space and Time Voids do actually exist Voids do actually exist Space and time are not the same things as corporeal entities Space and time are not the same things as corporeal entities Space and tiem may be measured by corporeal entities, but that does not mean they are corporeal entities Space and tiem may be measured by corporeal entities, but that does not mean they are corporeal entities Space is Infinite and Eternal Space is Infinite and Eternal Space and time exist independently of God Space and time exist independently of God God creates in space and time God creates in space and time Tremendous influence on Robert Boyle and Isaac Newton Tremendous influence on Robert Boyle and Isaac Newton Gassendi was not condemned, nor even censured by the Church Gassendi was not condemned, nor even censured by the Church

The Giant of the Scientific Age: Isaac Newton The most famous man in Europe in his own day and thereafter until Einstein The most famous man in Europe in his own day and thereafter until Einstein Alexander Pope: “Nature and nature's laws lay hid by night; God said let Newton be and all was light” Alexander Pope: “Nature and nature's laws lay hid by night; God said let Newton be and all was light” Combined techniques of rationalists and empiricists Combined techniques of rationalists and empiricists Founder of calculus; Fundamental discoveries in optics, mechanics, gravitation Founder of calculus; Fundamental discoveries in optics, mechanics, gravitation Very deeply religious; focuses on Biblical exegesis, not physics, at end of his life Very deeply religious; focuses on Biblical exegesis, not physics, at end of his life However he rejected Jesus as divine; considered himself an Arian However he rejected Jesus as divine; considered himself an Arian

So who thought what about a void? A void exists A void exists Gassendi, Pascal, Boyle, Newton Gassendi, Pascal, Boyle, Newton Does not exist Does not exist Descartes, Hobbes, Leibniz Descartes, Hobbes, Leibniz Belief in necessity of an ether lasts until Michelson-Morley experiments (1887) Belief in necessity of an ether lasts until Michelson-Morley experiments (1887)

Development of a new secular philosophy: Enlightenment Science (as we now define it) as the basis for knowledge; Science (as we now define it) as the basis for knowledge; Human reason can figure it (anything, everything) out; is always making progress Human reason can figure it (anything, everything) out; is always making progress Devalue history, tradition Devalue history, tradition Toleration as the basis for political-religious relationship; Toleration as the basis for political-religious relationship; Separation of Church and State Separation of Church and State Individual rights, not duty, as basis for political systems and society; Individual rights, not duty, as basis for political systems and society; Social contract not natural law as basis of legal system Social contract not natural law as basis of legal system Becomes an alternative to established religions Becomes an alternative to established religions