General Philosophy 1 & 2: Historical Background
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General Philosophy 1 & 2: Historical Background General Philosophy What is “General Philosophy”? Dr Peter Millican, Hertford College Some central issues of epistemology Lectures 1 and 2: (“What can we know?”) and metaphysics Historical Background (“What is the nature of things?”). Illustrates how philosophy is done: types of arguments, methods of enquiry etc. Historical focus: all but one of the topics (Knowledge) are introduced through the writings of “Classical” philosophers of the 17th and 18th centuries. 2 1 2 Why Study Philosophy Historically? The Value of Historical Perspective How the agenda got set: when and why did Philosophical ideas tend to have broad and these problems become important? deep interconnections. Learning the labels: “Cartesian dualism”, Studying classic “battles of ideas” enables “Lockean veil of perception”, “Berkeleian us to view these interconnections in context idealism”, “Berkeleian instrumentalism”, and with the perspective of history. “Humean compatibilism”, “Cartesian” or Many classic themes recur throughout the “Humean” scepticism etc. history of thought, sometimes hidden under Great original thinkers, writing for a general the surface of contemporary debate. audience: so their ideas are profound, and Ignoring the past can make us slaves of they don’t take too much for granted. 3 4 fashion, and blinker us to other options. 3 4 The Topics (1) The Topics (2) Scepticism: Descartes’ evil genius, Free Will: Hobbes’ and Hume’s Locke’s veil of perception compatibilism, and their naturalistic view of Knowledge: Responding to scepticism man as part of nature Perception: Locke’s representative Mind and Body: Descartes’ dualism, theory of perception, Berkeley’s criticisms various philosophers on the limited powers Primary and secondary qualities: Boyle of matter and their religious implications and Locke’s theory, Berkeley’s criticisms Personal Identity: Locke’s attempt to Induction: Hume’s sceptical argument, ground this independently of “spiritual and his denial that nature is “intelligible” substance” 5 6 5 6 Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background The Birth of Philosophy The Institution of Scholasticism The ancient Greeks, distinctively, Roman Empire became Christianised: aimed for rational understanding – Pagan temples and libraries destroyed 391 AD; independent of religious tradition. – Non-Christian “schools” closed down 529 AD. Many different philosophers and “schools”: Plato and Aristotle adopted: – Various “Pre-Socratics” (c. 600 - 400 BC) – Christian Platonism (e.g. Augustine 354-430) – Plato and his Academy (387 BC -) – Christian Aristotelianism (e.g. Aquinas 1225-74) – Aristotle (pictured) and his Lyceum (335 BC -) – Pyrrhonian sceptics (c. 320 BC -) The Christian Aristotelian worldview became – Epicureans (c. 307 BC -) dominant in the medieval monastic schools, – Stoics (c. 300 BC -) hence “Scholasticism”. 7 8 7 8 Fixed Stars Saturn Jupiter Rediscovery of the Classics Mars Sun Ancient texts survived in the Byzantine Venus Empire, or in the Arabic world. Mercury – Manuscripts brought West when the Ottoman Moon Turks attacked, fostered the development of Fire Humanism in Renaissance Italy. Air Printing (invented 1450) gave them much Water & Earth wider circulation, e.g.: – Lucretius (rediscovered 1417, printed 1486) – Sextus Empiricus (translated into Latin 1562) Aristotle’s Universe 49 10 9 10 Upheaval and Instability The Hereford Many factors contributed to Western instability in the period 1500-1650, e.g.: “Mappa – growth of population and trade; Mundi” – discovery of the New World (America etc.); (c. 1290) – consequent economic disruption; based on the writings – realisation that ancient maps etc. were wrong; of Orosius, a pupil of – suggestions of cultural relativity; Saint Augustine, part of a compendium of – technology of gunpowder and consequent knowledge to refute centralisation of power. the pagans 11 12 11 12 Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background The Reformation The Problem of the Criterion The Reformation added to this crisis: A sceptical problem raised by Sextus – Luther rebelled against the Church of Rome, Empiricus in his Outlines of Pyrrhonism: starting in 1517; How can any criterion of reliable knowledge – Many parts of Europe (especially in the North) be chosen, unless we already have some became Protestant; reliable criterion for making that choice? – Savage wars throughout Europe arising from – Roman Catholics appeal to tradition (Church, religious differences (e.g. Thirty Years’ War Bible, Aristotle); Protestants appeal to the 1618-48, English Civil War 1639-51); believer’s personal response to the Bible; – Peace “of exhaustion” at Westphalia, 1648 led – How to know who is right? (Maybe neither?!) to greater religious toleration. 13 14 13 14 Aristotelian Science Intelligibility, or Empty “Explanation”? Elements and Natural Motions “Why does water rise up a siphon pipe?” – Four elements: fire, air, water, and earth. “Because Nature abhors – Fire/air naturally move upwards, water/earth a vacuum.” downwards, each seeking its natural place. “Why does opium – Heavier things fall faster, in proportion to weight. (Physics, IV 8) make one sleep?” A Teleological Physics “Because it contains a – Strivings, horror of a vacuum etc. dormitive virtue, whose – Everything strives towards the eternal, hence nature is to make the heavenly bodies move in circles, and must be senses soporific.” made of a fifth element, aether. Molière (1673) 15 16 15 16 Galileo’s Experiments Galileo’s Telescope Aristotle couldn’t explain: The telescope was invented in Holland in – the flight of a cannonball; 1608, and Galileo made his own in 1609. – a sledge sliding on flat ice; What he saw with it refuted Aristotle’s – water dripping from a gutter. cosmology: – Mountains and valleys on the moon; Galileo was reported (by Viviani) to have performed another critical experiment: – Four moons orbiting around Jupiter; – Innumerable stars too dim for the naked eye; – dropping a large and a small ball together from the Leaning Tower of Pisa. Contrary to – Phases of Venus, sometimes “full” (implying that Aristotle, they fell at similar speeds. it is then on the opposite side of the Sun). 17 18 17 18 Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background Sun Venus as From Final to Efficient Causes considered by Ptolemy Aristotelian science was based on Venus purposes, or “final” causation: – Things strive to reach their natural place, or to avoid abhorrent situations (e.g. a vacuum); Galileo preferred “efficient” causation: – The outcome depends on where the causal sequence happens to lead. – Matter doesn’t strive; it is inert, remaining in Earth its state of motion or rest unless acted on. 14 20 19 20 The “Mechanical Philosophy” Inertia and the Orbiting Heavens The paradigm of efficient causation is via Thus Galileo claimed, against Aristotle: mechanical contact: – Matter does not “strive”. – Interaction between contiguous particles of – Left to itself matter is “inert”: it continues in a matter by pressure and impact. uniform state of rest or motion until acted Compared with pseudo-explanations upon by a force (e.g. pushed along). involving “occult” qualities (horror of a – The heavenly bodies are not composed of a vacuum, dormitive virtue etc.), this seems: special “aether”, but of ordinary matter, and therefore subject to the same laws. – genuinely explanatory; – genuinely intelligible. BUT: why then does the Moon orbit the Earth, and the planets orbit the Sun? 21 22 21 22 The Father of Modern Philosophy Descartes – Epistemology Attacks Aristotlian tradition Seeks reliable anti-sceptical basis for using the sceptical problem knowledge, not appealing to authority: of the criterion; – “I think therefore I am”, provides a first Builds on Galileo’s example of something known, and reveals mechanical philosophy what is needed: clear and distinct perception. grounding it on a theory of – Then prove clearly and distinctly that the idea matter’s “essence”; of God implies a perfect cause: i.e. God. Makes room for mind – A perfect God cannot deceive, so our faculties must be reliable if used properly. as an “essence” radically distinct from matter. – Hence the importance of Descartes’ Method. 23 24 23 24 Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background Descartes – Science Descartes and Essences Descartes was a major natural philosopher: The real qualities of matter follow from its – First to explain the rainbow in detail; essence, simple geometrical extension. – Discovered co-ordinate geometry; – This essence, known through God-given innate – Suggested circulation of the blood; ideas, implies mathematical laws of motion. – Concluded that the Earth orbits the Sun. – Bodies are passive, remaining in the same state (inertia) until a force is applied. His most important intellectual legacy: – Qualities perceived by the senses (Locke’s The ideal of a mechanistic science of the world, “secondary qualities”) are observer-dependent. based on the simple mathematical properties of extended matter. Mind is a distinct, active immaterial substance, whose essence is thinking. 25 26 25 26 Descartes’ Physics The Monster of Malmesbury (and Magdalen Hall = Hertford College!) Since matter’s essence is extension, non- material extension is impossible. Thus: Hobbes denies – The physical world is a plenum (no vacuum); – immaterial