General Philosophy 1 & 2: Historical Background
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.
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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
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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.
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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.
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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 substance; – All motion must take the form of circuits of – witchcraft; matter within the plenum. – reliance on revelation. – This can be expected to give rise to vortices, Hobbes asserts circular motions like whirlpools. – universal determinism; – A vortex can explain why the planets orbit the – obedience to sovereign Sun without shooting off under inertia. in religion and morals.
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Hobbes’ Hobbes’ Materialism Leviathan (1651) Hobbes, like Descartes, is a plenist, but he recognises only material substance, and does In the state of so on logical grounds: nature, the life of “When men make a name of two Names, whose man is ‘solitary, significations are contradictory and inconsistent”, poore, nasty, the result is “but insignificant sounds”, “as this brutish and short’. name, an incorporeall body, or (which is all one) an incorporeall substance”. Leviathan ch. 4 The only solution is absolute So Descartes’ supposed mental “immaterial sovereignty. substance” is a contradiction in terms! 29 30 29 30
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Hobbes’ Compatibilism Materialism and Atheism
Hobbes is the first classic compatibilist, who Hence for Hobbes, all that exists is material, takes determinism (i.e. all that happens is even God, and everything is determined. completely determined by causal laws) to Many took Hobbes to be an atheist. be fully compatible with genuine free will. – In 1666 Parliament cited his “atheism” as “LIBERTY, or FREEDOME, signifieth (properly) the probable cause of the plague and fire of London! absence of Opposition (by Opposition, I mean – His “Pernicious” books were publicly burned in externall Impediments of motion;) … A FREE- Oxford in 1683, because of their “Damnable MAN, is he, that in those things, which by his Doctrines … false, seditious, and impious, and strength and wit he is able to do, is not hindred most of them … also Heretical and Blasphemous to doe what he has a will to.” … and destructive of all Government”. 31 Leviathan ch. 21 32 31 32
The Evils of “Hobbism” Opposing Materialism
In 1668, Daniel Scargill of Corpus Christi The main argument against Hobbist Cambridge was expelled. In his public materialism was to insist on the limited powers recantation, he confessed: of “brute matter”, which: “I have lately vented and publickly asserted … – is necessarily passive or inert (as demonstrated by divers wicked, blasphemous, and Atheistical the phenomenon of inertia); positions … professing that I gloried to be an – in particular, cannot possibly give rise to mental Hobbist and an Atheist … Agreeably unto activity such as perception or thought. which principles I have lived in great This point was pressed by Ward (1656), More licentiousness, swearing rashly, drinking (1659), Stillingfleet (1662), Tenison (1670), intemperately … corrupting others …” Cudworth (1678), Glanvill (1682), Locke (1690).
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Boyle’s Corpuscularianism Atoms and the Void
Though Hobbist materialism Boyle’s universal matter is both extended was anathema, physical and impenetrable, so unlike Descartes he mechanism thrived in England: can draw a distinction between: – Robert Boyle, with an interest in – impenetrable extension (i.e. matter) chemistry and based in Oxford, – penetrable extension (i.e. empty space) speculated that material He retains Descartes’ primary-secondary substances are composed of imperceptible “corpuscles” made of “universal matter”. His quality distinction: observable “secondary” term “corpuscularianism” conveniently avoided qualities of substances flow from how the the atheistic associations of ancient “atomism” corpuscles are physically arranged.
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Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Meanwhile, Newtonian Physics in the Heavens … Isaac Newton took In 1627 Johannes Kepler published tables Descartes’ concept of enabling the calculation of planetary positions inertia, and Boyle’s theory to an accuracy which turned out to be over of “atoms and the void”, but 1000 times better than any previous method. postulated a force of gravity acting through it. Kepler’s method is based on the hypothesis – If gravity acts in inverse proportion to the square that each planet moves in an ellipse around of the distance between two objects, and bodies the Sun (which is at one “focus” of the ellipse). accelerate in proportion to the total force acting The method’s sheer accuracy led over time to on them, then the elliptical motion of the planets general acceptance of that hypothesis. around the Sun can be elegantly explained. 37 38 37 38
Refuting Aristotle and Descartes Gravitation and Intelligibility
Newton’s theory could also predict – using Newtonian gravity acts at a distance with the very same equations – the motion of no intermediate mechanical connexion. cannonballs etc. on Earth. – But this is deeply “unintelligible”. – Another nail in the coffin of the Aristotelian – Descartes had objected to the idea of gravity supposition that heavenly bodies act differently. as “occult”: one body would have to “know” In his Philosophiae Naturalis Principia where the other was to move towards it. Mathematica (1687), Newton also proved – Many Newtonians took the operation of mathematical results indicating that a vortex gravity to be proof of divine action, a new could not possibly generate elliptical motion. resource against Hobbist materialism. – Descartes’ theory was thereby discredited. – Newton took a more instrumentalist attitude. 39 40 39 40
Newton’s Methodological John Locke Instrumentalism Newton’s public response to the objection: Established “British “Hypotheses non fingo” Empiricist” tradition; – “I feign no hypotheses”; there’s no obligation to Hugely influential also in invent speculations about how gravity operates political philosophy; (at least until more evidence comes to light Christ Church, 1652-84; giving a basis for more than mere hypothesis). Essay concerning – If the gravitational equations (etc.) correctly Human Understanding describe the observed behaviour of objects, and Two Treatises of then that theory should be accepted whatever Government, 1690. the unperceived underlying reality might be.
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Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Locke and Corpuscularianism Empiricism and Essences
Locke’s Essay took Boyle’s “corpuscularian Locke is empiricist, and modest … hypothesis” as the best available: – All our ideas are derived from experience, so – Boyle’s “universal matter” becomes “substance we can’t rely on Cartesian “innate ideas”. in general”; “impenetrability” becomes “solidity”. – (Virtually) all knowledge of the world comes – Underlying substance has primary qualities: from experience, and hence must be tentative. shape, size, movement etc., texture, solidity. – We presume a “real essence”: an underlying – Secondary qualities (e.g. colour, smell, taste) are structure giving rise to the observed properties powers to cause ideas in us. of substances, and their similarity. – Primary qualities in objects resemble our ideas – However we have to make do with relying on of them; secondary qualities do not. “nominal essence”: the observable properties by which we identify and sort things. 43 44 43 44
Locke’s Probabilism Locke’s Rationalism
Reason is a perceptual faculty: rational Despite his epistemological modesty, Locke argument involves perceiving truths and seems committed to an ideal of intelligibility: inferential connexions. – “if we could discover the … Texture [etc.] … of – Demonstration is when a sequence of intuitive the minute Constituent parts of … Bodies, we connexions leads from premise to conclusion. should know without Trial several of their But reason does not operate only through Operations …” (Essay IV iii 25) logical demonstration, yielding certainty: – The existence of God is provable with certainty, since “it is as impossible that incogitative Matter – Reason can also perceive probable should produce a cogitative Being, as that connexions, which can be sequenced nothing … should produce … Matter.” (IV x 11) together to generate probable reasoning. 45 46 45 46
Thinking Matter and Inertness Locke on Personal Identity
But Locke speculated that God could, if he Agnosticism about substances gave Locke wished, “superadd” thought to matter. a particular problem with personal identity. – Provoked great hostility, opponents arguing – Our experience gives us no insight into the that thought is an “active” power, requiring an nature of mental “substance”, only its activity. immaterial soul rather than brute matter. – Analogy with plants suggests an organism’s – Matter only has primary qualities and what identity is not tied to its constituent substance. directly flows from them. – The notion of personal identity is “forensic”: – Matter is clearly “passive” or “inert”, as vital in issues of morality and responsibility. indicated by phenomenon of inertia. Locke attempts to ground this vital notion – If matter could think, what of immortality? in consciousness and memory. 47 48 47 48
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
The Powers of Matter Nicolas Malebranche
Most were deeply unhappy with a view of man The leading Cartesian of that was compatible with materialism, which the late 17th century. they saw as atheistical and mortalist. Often now ignored, but Again, their main argument was that matter is influential in England as passive and inert, so it cannot perceive or think well as his native France. (Descartes, Cudworth etc.), or attract gravitat- ionally (various Newtonians); hence there must Built on the claim of matter’s inertness, be a non-material substance with these effects. developing the theory of occasionalism. Occasionalism and Immaterialism pushed this Though considered a “rationalist”, he was a line of thought much further … major influence on the “empiricist” Berkeley. 49 50 49 50
Malebranche and Causation Malebranche’s Occasionalism
Matter is inert, and has no causal impact Malebranche’s theory implies that physical on the world; the only cause is God. objects are not real causes. – A real cause must necessitate its effect, but we – Instead they are “occasional” causes: when can conceive any physical “cause” occurring one billiard ball hits another, this provides the without its “effect”, so it can’t be a real cause. occasion for God to cause the second to move – Only the will of an omnipotent Being can truly (by re-creating it in a sequence of positions). necessitate an effect in this sense. – God also creates the visual perceptions in our – God sustains the world, in effect re-creating it mind corresponding to this physical reality. from moment to moment (as Descartes taught), – But then why not do away with the physical hence again He brings everything about. reality entirely, as it seems to play no role?
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George Berkeley Berkeley’s Immaterialism
Irish Anglican, 1685-1753, Berkeley’s immaterialism is essentially buried in Christ Church. occasionalism without the material world. “British empiricist”, but But he uses a different set of arguments, closer to Malebranche than appealing to perception and meaning- to either Locke or Hume. empiricism rather than to metaphysics: Immaterialism: the only things that exist are – Combines Lockean principle that only ideas are immediately perceived, with plain man’s belief (active) spirits and (passive) “ideas”. that trees etc. are immediately perceived; God orchestrates our ideas, so objects in the – Denies intelligibility of perceived objects (or world appear in an orderly fashion. anything resembling them) existing unperceived. 53 54 53 54
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Perception According to Locke Perception According to Berkeley
Idea in the mind Material object Idea in the mind = the tree (directly perceived) (cause of the idea) (directly perceived; caused by God)
The “Veil of perception” problem: how can we No veil of perception problem, because what we know whether there is a real material object? directly perceive (i.e. the idea) is the tree.
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Berkeley on Primary and Berkeley’s Instrumentalism Secondary Qualities Immaterialism might seem to undermine We can be mistaken about PQs just as about physical science, but Berkeley (following SQs: they too are in the mind. Newton) advocated instrumentalism: All ideas are derived from experience, hence – The aim of science is to discover “laws” that our ideas of PQs (e.g. shape) are infused generate true predictions about phenomena. with those of the sensory SQs by which we – It is irrelevant whether the theoretical entities perceive them (e.g. a colour that fills the (e.g. forces) invoked have any real existence. space). PQs without SQs are inconceivable. – God benevolently arranges the observed We cannot make any sense of something phenomena to follow these patterns, as “signs” non-mental resembling an idea. to enable us to direct our lives. 57 58 57 58
David Hume, The Great Infidel Building on Newton and Locke
Scottish, 1711-76 Newtonianism Treatise of Human – Newton provides a model of good science, Nature 1739 modestly aiming “to reduce the principles, Essays (various) 1741- productive of natural phenomena, to a greater Enquiries concerning simplicity, and to resolve the many particular Human Understanding effects into a few general causes”. (E 30) 1748, and Principles of Probabilism Morals 1751 – Locke is right to emphasise probability rather Dialogues Concerning than demonstration as the basis for our Natural Religion 1779 discovery of truths about the world. BUT …
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Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Hume on Mechanical Causation Science and Intelligibility
Suppose we see a white billiard ball moving Methodological Instrumentalism towards a red one and colliding with it. Why – All causation is “unintelligible”: we don’t really do we expect the red one to move? understand why anything causes anything. Imagine Adam, newly created by God, trying – Malebranche and Berkeley had the right idea to envisage what would happen: how could about natural causes: there is no intelligible be possibly have any idea at all in advance connexion between cause and effect, so we must view all “natural laws” instrumentally of experience? (and not just Newton’s law of gravitation). The “intelligibility” of mechanical causation – But in Hume’s universe there’s no role for is just an illusion, engendered by familiarity. God: it’s a sort of atheistic occasionalism!
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Hume on Induction Humean “Reason”
Does experience of impacting billiard balls Against Lockean “Rationalistic Probabilism” give me a good reason for expecting the red – Lack of “intelligibility” does not merely imply that ball to move after the collision? our judgements about the world are uncertain; If so, I must have a good reason for taking we cannot even claim to have any rational my past experience as a guide to the future. grasp of, or insight into, probable connexions. But resemblance of the future to the past isn’t The Foundation of Induction self-evident, and I can’t know it through the – Scientific (like all empirical) reasoning is senses. Nor can it be proved logically, while founded not on insight, but on a brute appealing to experience to support it would assumption that the future will resemble the be “begging the question”: arguing in a circle. past, for which no solid basis can be given. 63 64 63 64
Man’s Place in Nature Hume on Free Will
Not “Made in God’s Image” Hume, like Hobbes, is a compatibilist, seeing – Our Reason is a natural faculty (rather than any moral freedom as compatible with determinism. sort of godlike insight). There’s no basis for Human actions are necessary in the same thinking of man as supernaturally privileged; sense as material interactions (indeed we can instead, he should be viewed as part of the only understand necessity in one way, based on natural world, alongside the beasts. our own habits of prediction). A Subject of Empirical Study Free will is simply having the power to act as – The human world, like the natural world, can be our will dictates. known only through observation, experiment, This doesn’t undermine moral responsibility systematisation and generalisation. because morality is based on sentiment. 65 66 65 66
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
The Elephant in the Room A (Very Simplistic) “Big Picture”
Theological concerns underlie Physics Morals Politics most philosophy over this period.
In the Medieval picture, things Governed Revealed King is operate through “natures” and purposes laid Medieval by natural truth and divinely down by God. Moving from an Aristotelian to a motions natural law ordained mechanical model of nature removes the purposes, and threatens an atheistic universe. Inert matter, Revelation? Natural right? Religious disagreement also undermines Early mechanical Reason? Reason? appeal to traditional authority – encouraging a Modern causation, Moral sense? Contract? search for something to take its place. forces Feeling? Raw power? 67 68 67 68
In the Wake of Mechanistic Science Moreover a completely mechanical account of the actions of body implies that our behaviour is determined. What then of free will, and how The world differs radically from how it appears: can divine punishment be justified? our best theory attributes primary qualities to bodies, with secondary qualities explained Reward or punishment relies on the premise of through a representative theory of perception. personal identity over time, and the afterlife requires this to withstand bodily dissolution. This invites scepticism: if we can’t trust our How can we make sense of this, so as to natural faculties to yield truth directly, then how safeguard both religion and morality? can we know what things are really like? If Hume is right, we can’t. And our attempts to If the actions of body are explained mechan- make sense of the world are anyway doomed ically, then how can mind fit in? The relation by the limits of our faculties, as shown by our between them seems completely mysterious. inability to justify even basic induction. 69 70 69 70
Immanuel Kant (1783) Hume’s Triumph!
Hume has to be wrong, Darwin’s On the Origin of Species (1859) because we have clear – We are evolved from animals, part of nature. examples of “synthetic a Einstein’s General Relativity (1915) priori” knowledge: truths – Space is gravitationally “curved”. about the world knowable independently of – So Euclid’s axioms probably aren’t true, and experience, that we see had to be that way: they’re certainly not knowable a priori. – Metaphysical principles (e.g. universal causation) Quantum Mechanics (1925) – Euclidean geometry (e.g. Pythagoras’ theorem) – Fundamental particles don’t work at all as we – Newtonian mechanics (e.g. conservation of (or Newton) would have expected: their momentum). behaviour is describable, but not “intelligible”. 71 72 71 72
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
General Philosophy Hume’s Fork
Dr Peter Millican, Hertford College Enquiry IV starts with a vital distinction between types of proposition: Lecture 3: – Relations of ideas can be known a priori (i.e. Induction without dependence on experience) by inspecting ideas; hence their falsehood is inconceivable and they are necessarily true. e.g. Pythagoras’ Theorem. (E 4.1) 3 × 5 = ½ × 30. (E 4.1) All bachelors are unmarried. – The modern term is analytic (as understood e.g. by Ayer): “true in virtue of its meaning”. 74 73 74
Matters of Fact Suppose we see a yellow billiard ball moving towards a red one and colliding with it. We – Matters of fact can’t be known a priori, and their expect the red one to move – but why? truth / falsity are equally conceivable: e.g. The sun will rise tomorrow. (E 4.2) The sun will not rise tomorrow. (E 4.2) This pen will fall when released in air. – The modern term is synthetic: a proposition whose truth “is determined by the facts of experience” (Ayer, LTL 1971, p. 105). Because we suppose a causal connexion So how can I discover a matter of fact which between the two events. But in that case … I neither perceive directly, nor remember? How do we learn about causes and effects? 75 76 75 76
A Thought Experiment The Need for Extrapolation
Imagine Adam, newly created by God, trying All inference to matters of fact beyond what to envisage the effect of the collision: we perceive or remember seems to be based – how could he possibly on causation, and all our knowledge of causal make any prediction at all relations comes from experience. in advance of experience? Such learning from experience takes for granted that observed phenomena provide a guide to unobserved phenomena. We thus extrapolate from past to future on the assumption that they resemble. But do we have a rational basis for doing so? 77 78 77 78
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Four “Kinds of Evidence” Locke on Reasoning
“It is common for Philosophers to distinguish the In demonstrative reasoning, each link in the Kinds of Evidence into intuitive, demonstrative, inferential chain is “intuitively” certain. sensible, and moral”. (Letter from a Gentleman, – “reasoning concerning relations of ideas” [Hume] 1745, p. 22) In probable reasoning, some links in the By “intuition”, Hume means immediate self- inferential chain are merely probable. evidence: the way we know that something is – “moral reasoning”, “reasoning concerning matter identical with itself, or that 2 is greater than 1. of fact” [Hume]: “factual inference” for short “Sensible” evidence means from the senses. For Locke, both types of reasoning involve “Demonstrative” and “moral” reasoning are now rational perception of the links (IV xvii 2). commonly called “deduction” and “induction” … 79 80 79 80
Hume on Inferring Uniformity Review: The Part (i) Argument
What ground can we give for extrapolating All factual [moral, probable] inference is from observed to unobserved? founded on causation – Self-evident intuition? No. – Because causation is the only relation that – Demonstrative reasoning? No: neither of enables us to infer from one thing to another. these, because it’s clear that extrapolation All knowledge of causal relations is could fail, so it can’t be a matter of pure logic. founded on experience – Sensory knowledge? No: what we perceive – A priori, we can know nothing of causation. of objects gives us no insight into the basis of their powers, hence no reason to extrapolate. Hence all factual inference is founded on – Factual inference? No: that would be circular. experience. 81 82 81 82
The Pivot The Part (ii) Argument
All factual inference is founded on But neither intuition, nor sensation, nor experience. demonstration can ground such a principle. All inference from experience is founded And factual inference – as we have seen – on a principle of uniformity or similarity. itself depends on the Uniformity Principle, – Because it requires that we extrapolate from so any attempt to establish the Principle by our experience, on the basis that what we factual inference will be arguing in a circle. have not yet experienced will be similar. It follows that there is no rational basis for Hence all factual inference is founded on the supposition of Uniformity, and hence no this Uniformity Principle. rational basis for factual inference.
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Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
The Basis of Factual “Reason” Does This Imply Irrationalism?
Our “reason” is fundamentally based on a Does Hume deny that inductive inference brute assumption of uniformity, rather than is founded on any sort of rational insight any insight into the nature of things. into why nature should be uniform? – Hence human reason differs from animal – YES! reason only in degree. Does Hume think that all inferences about – Locke’s supposed “perception” of probable “matter of fact” are equally hopeless, so connexions is wishful thinking. that there’s no rational ground for – No causal interactions are really intelligible: preferring one to another? we discover what causes what not by pure thought, but by observation of uniformities. – NO! 85 86 85 86
The Problem of Demarcation Implications for Science
Religious belief is founded on “whimsies Systematisation rather than Intelligibility and prejudices” of the imagination. – “the utmost effort of human reason is, to reduce Science is founded on the instinctive, non- the principles, productive of natural phenomena, rational belief in uniformity. to a greater simplicity, and to resolve the many particular effects into a few general causes … So what right has Hume to prefer “science” But as to the causes of these general causes, over “superstition”? His answer is to favour we … in vain attempt their discovery.” (E 4.12) reasoning consistently with this irresistible Instrumentalism instinctive belief, which is so utterly – Newton’s instrumentalist attitude to gravitation essential to human life and thought. thus provides a model of good science.
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The Gap in Hume’s Argument Other Attempts to Answer Hume
Hume takes for granted that all “probable” “Analytic” Justification of Induction arguments must be based on experience. – Induction is rational by definition: it is partly So it might be possible to escape his constitutive of our concept of rationality. argument if induction could be justified “Inductive” Justification of Induction using a priori probabilistic considerations. – Induction is justified by its past success. Though most philosophers are sceptical, “Pragmatic” Justification of Induction interesting attempts have been made by: – We are pragmatically (rather than epistemic- – Bruno De Finetti (1937), D.C. Williams (1947), ally) justified in relying on induction, because David Stove (1986), Sir Roy Harrod (1956), it will work if any method of prediction will. Simon Blackburn (1973), J. L. Mackie (1979) 89 90 89 90
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Hume versus Strawson The Inductive Justification
P. F. Strawson (Univ and Magdalen) fam- Max Black (1958) argued that induction can ously advocated the “Analytic Justification”. be justified inductively without vicious However it’s not clear that it really engages circularity, by distinguishing between an with Hume’s problem. Hume himself would inductive rule and an inductive premise. agree that we call induction “rational”, and But Hume’s question concerns the rational even that we’re right (in a sense) to do so. well-foundedness of taking the observed as His sceptical result doesn’t concern this use evidence for the unobserved. A rule or premise can confer this rational grounding of words: it questions our epistemic only if it is itself rationally grounded. So justification for inductive extrapolation. any circularity here is indeed vicious. 91 92 91 92
The Pragmatic Justification Mellor on Warranted Induction
Hans Reichenbach (1949) argued that if Mellor takes an “externalist” approach: there is any general rule, deterministic or induction is warranted if the world is such as statistical, to be found – e.g. that 61% of As to make inductive predictions probably true are Bs – then induction will find it, and is (e.g. because the world does in fact behave better than any alternative method. consistently over time), even if we are unable But this argument just takes for granted that to know that this is the case. we are looking for an inductively consistent For the externalist, a belief can be justified by rule: one that stays the same over time. how things are, even if the believer is Besides, Hume’s pragmatic justification is unaware of what justifies his or her belief. stronger: we can’t help reasoning inductively! We’ll consider externalism in “Knowledge”. 93 94 93 94
Goodman’s “New Riddle” of Induction “Grue” seems artificial because it’s defined in terms of “green” and “blue”. But “green” can be defined in terms of “grue” and “bleen”! Call something grue if it is first examined before noon on 1st April next year and is The easiest answer is to say that Goodman’s green, or first examined later and is blue. bent predicates don’t latch on to real (Bleen is the other way round.) properties, and inductive support depends on real similarities between things, not on purely Suppose all emeralds examined so far are syntactic relationships between sentences green. Then we have two rival theories, both (unlike formal deductive validity). supported by all the available evidence: st (a) All emeralds are green. (“straight” theory) To back this up, consider a how miner on 1 April could know the colour of an emerald that (b) All emeralds are grue. (“bent” theory) he digs up: to tell whether it’s grue or bleen, How can we justify preferring (a) over (b)? 95 96 he’d have to know the time. 95 96
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
General Philosophy Scepticism, and the Mind Dr Peter Millican, Hertford College Last Time … Lecture 4: … we looked at scepticism about INDUCTION. Two Cartesian Topics This Lecture … … will move on to SCEPTICISM concerning the external world, most famously exemplified in Descartes’ first Meditation, and his related claims about the nature of MIND AND BODY. The Next Lecture … … will say more about modern responses to SCEPTICISM, and focus on KNOWLEDGE. 98 97 98
Two Kinds of Scepticism External World Scepticism
Vertical Scepticism It can seem that (“vertical”) external world – Inferring from one kind of thing to a different scepticism is far more worrying than kind (e.g. inferring from one’s sensations or (“horizontal”) inductive scepticism: appearances, to the existence of real physical – Maybe I am just dreaming, and there is no objects that cause them). external world at all. Horizontal Scepticism – Maybe an evil demon is causing me to have – Inferring things of the same kind as one has illusions of an external world. experienced (e.g. inferring from one’s – Maybe a wicked scientist has my brain in a sensations or appearances, to expect similar vat, and is creating these illusions. sensations or appearances in the future).
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Descartes’ Approach Descartes and God
The only way to defeat scepticism is to Hence I can establish as a general rule withhold assent from anything that isn’t that anything I clearly and distinctly completely certain. perceive is true. When I consider “I think, therefore I am”, it I clearly and distinctly perceive that God is quite impossible for me to be mistaken. must exist, because only a perfect being So I am completely certain of this, at least. could be the ultimate cause of such a By contemplating this first certainty, I perfect idea as my idea of God. understand what makes it certain is that I A perfect God cannot deceive, so I know clearly and distinctly perceive it to be true. that my faculties are essentially reliable.
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Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
The Cartesian Circle Moore’s Response
Descartes seems to be “boot-strapping”: G.E. Moore famously claimed to refute this – proving the existence of God by relying on his sort of scepticism by appeal to common- mental faculties. sense knowledge: – then appealing to the existence of God to – Here’s one hand [he holds up a hand], and justify reliance on his mental faculties. here’s another [he holds up the other]. Isn’t this viciously circular? – If this is a hand, then there is an external – If my faculties might be defective, then how world. can I trust my proof of the existence of God in – Therefore there is an external world, and the first place? How can any anti-sceptical scepticism is refuted. argument even get off the ground? 103 104 103 104
Two Arguments from “P implies Q” One person’s modus ponens …
Modus Ponens Deuteronomy 20:16-17 commands multiple P implies Q P Q genocide to avoid religious pollution. P is true P The religious fundamentalist might say: therefore Q is true Q Everything in the Bible is true. Therefore genocide is sometimes desirable. Modus Tollens The humane philosopher would say: P implies Q P Q Genocide is never desirable. Q is false Q Therefore not everything in the Bible is true. therefore P is false P Which underlined premise is more plausible?
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… is another’s modus tollens … Internalism and Externalism
– If this is a hand, then there is an external world. We’d like to agree with Moore, but it seems Moore says: hard to justify a claim to knowledge so – We know this is a hand. crudely: don’t we need some philosophical argument rather than a bare common-sense – Therefore we know there is an external world. claim to justify knowing that this is a hand? The sceptic says: But “internalist” arguments, like Cartesian – We don’t know that there is an external world. boot-strapping, have difficulty doing the job. – Therefore we don’t know that this is a hand. So many recent philosophers have moved Moore will claim that his premise is more towards externalism (next lecture, and plausible than the sceptic’s. compare Mellor’s approach to induction). 107 108 107 108
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Cartesian Dualism A Bad Argument for Dualism
The view for which Descartes In his Discourse, Descartes argues like this: is now best known: I can doubt that my body exists. – The body is material, composed of matter I cannot doubt that I exist. whose essence (i.e. fundamental property from I am not identical with my body. which other properties follow) is extension. Compare: – The mind is composed of immaterial substance I can doubt that Hesperus is Phosphorus. * whose essence is thinking. I cannot doubt that Phosphorus is Phosphorus. This substance dualism is to be contrasted Hesperus is not Phosphorus. with property dualism (i.e. there are both * Hesperus = the Evening Star; Phosphorus = the Morning physical and non-physical properties). Star; in fact both are appearances of the planet Venus. 109 110 109 110
Leibniz’s Law A Better Argument for Dualism
If a and b are the same thing, then any Descartes’ argument in Meditation VI is less property of a must also be a property of b: fallacious, but has questionable premises: Fa, a=b ╞ Fb – I have a clear understanding of myself as – If F is the property of being doubted by me to (potentially) a thinking, non-extended thing. exist, a is me, and b is my body, we get – I have a clear understanding of body as Descartes’ argument from the Discourse. (potentially) extended and non-thinking. – Likewise F could be the property of being – Anything I clearly and distinctly understand could doubted by me to be Prime Minister (etc.) be created by God accordingly. To simplest way to avoid the fallacy is to – So I could exist separately from my body, and it deny that these are genuine properties. follows that I am genuinely distinct from it. 111 112 111 112
From Doubt to Essence Epistemology Metaphysics?
Even in the Meditations, Descartes tries to The way in which we come to know, or be motivate his claim to know the essence of certain, of something need not reflect its mind (as thinking) from his doubt argument: ultimate nature (or why it is that way). “what shall I now say that I am [when I might be – From I am thinking, it plausibly follows that (in deceived by an evil demon, or dreaming]? … at least one sense) I am a thing that thinks. At present I am not admitting anything except – But it does not necessarily follow that I am what is necessarily true. I am, then, in a strict something whose essence is to think. sense only a thing that thinks; that is, I am a – Nor does it follow that the thing that thinks mind, or intelligence, or intellect, or reason … could exist without being extended. (Imagine what kind of thing? … a thinking thing. if a piece of matter were made able to think.) 113 114 113 114
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Possibly Distinct Actually Distinct? The Distinct Substances Problem
The final move of Descartes’ argument “How can two such distinct substances seems more defensible, in a sense: interact at all?” God could have created my mind and body – A problem for Descartes, who takes causation as separate entities. to be ultimately intelligible. It is possible for my mind and body to exist – Not a problem in principle on a Humean view of separately. causation: causation is a matter of lawlike My mind and body are in fact distinct things. correlation rather than intelligible connexion. But “could have” must be metaphysical – But it’s hard to see what such “laws” could be possibility, not epistemology (“might have like, so a difficulty remains (cf. the “explanatory gap” between physical and mental). for all I know”). So this begs the question. 115 116 115 116
The Causal Closure Principle Problems Explaining Interaction
The causal closure principle is that physical The causal closure principle seems to events (or their probabilities) are leave no room for a distinct mental determined entirely by physical causes. substance capable of influencing the body. – Also called “the completeness of physics”. Even if we deny the principle, mind/body – In this form, the principle is compatible with interaction seems mysterious. physical events’ being to some extent random. It’s hard to see how an immaterial mind – Casts doubt on non-physical causation. could have evolved alongside the body. Commonly believed, though its evidential – Do animals have one too? base is not so clear. – Is having a mind “all or nothing”?
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Mind and Body: Different Views The Knowledge Argument (Jackson) Interactionism – The mind can causally influence the body (e.g. Imagine a scientist (Mary) who learns all the movement), and vice-versa (e.g. pain). physical facts about colour and colour Epiphenomenalism perception, but who can see only in black, white, and shades of grey. – The mind is an “epiphenomenon” – caused by events in the brain, but itself causally inert. If she then acquires normal sight, when she (this account is particularly hard to square with sees colours she learns what they look like, evolution – how could such a mind evolve?) something she didn’t know before. Physicalism Hence these phenomenal colour properties – Only physical things exist, hence there is cannot be physical. We are forced into nothing to the mind beyond the physical brain. property dualism, if not substance dualism. 119 120 119 120
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
What is a Physical Cause? Non-Physical Explanation
What are the properties of physical matter? Even with “non-spooky” physicalism, it – If matter is just inert, extended (and possibly doesn’t follow that everything in the world impenetrable) stuff, then it’s hard to see how it can be explained in physical terms. could possibly be the causal basis of thought. – Why does my calculator show “132” when I – But quantum “matter” has all sorts of weird type “11 x 12 =“ ? properties: charge, spin, “charm”, “strangeness”. – Answer: because 11 x 12 is equal to 132. The – Could matter have some proto-psychic property explanation appeals to mathematical facts, not too (panpsychism: mind is a fundamental feature just physical facts about the calculator. of the universe)? Would this then be physical?! Likewise evolutionary explanation etc. (e.g. – Physicalism generally shuns such “spooks”. in terms of the logic of game theory). 121 122 121 122
The Hardware/Software Analogy Ryle and Category Mistakes
It is tempting to see the relation between The classic category mistake: brain and mind as analogous to that – “I’ve seen all these colleges and offices, but between hardware and software. where is the University?” – This treats the mind as clearly distinguishable – Supposes the University to be a separate thing. from the body, but not a distinct substance. “Mind” as a category mistake: Explains away another Cartesian argument: – “People behave in these various ways, so they Body is divisible. must have a mind distinct from their body.” Mind is not divisible. – Instead, “having a mind” just is a matter of how Body and mind are distinct. one behaves. It’s not a separate thing.
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Strawson and “Many Minds” The Hard Problem
If one does think of the mind as a separate Physicalism can comfortably accommodate: thing from the body, an “entity” in its own – Non-physical explanation (e.g. in terms of right, then this raises the question of how purposes, as with a chess computer); such entities are to be individuated. – A notion of “mind” analogous to software. How can I know my brain isn’t linked to But the “hard problem” (Chalmers) remains: lots of different minds thinking in unison? – Why is all this accompanied by phenomenal – Possible answer: I can’t be certain, but it’s an consciousness (i.e. conscious experience)? extravagant and arbitrary hypothesis. Can this justify substance dualism after all? – However Strawson would probably see even – Or should we rather admit that we simply don’t the possibility as a reductio ad absurdum. 125 126 (yet) understand it? Maybe we never will! 125 126
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
General Philosophy From Scepticism to Knowledge Dr Peter Millican, Hertford College Sceptical arguments, such as those of Lecture 5: Descartes, suggest that we know very Knowledge and Scepticism little. But we still want to distinguish between things that we consider we have a right to believe (e.g. on the basis of experience or strong testimony), and other less secure beliefs (e.g. “superstitions”). If the sceptical arguments can’t be answered, then it’s tempting to attack the problem by (re-?) defining “knowledge”. 128 127 128
What is Knowledge? What is Geography?
“What is X?” questions: “Geography” as a discipline: – X might be “truth”, “perception”, “reason”, “the – Initially, perhaps, described the study of places mind”, “personal identity”, “freedom”, etc. in terms of location, physical characteristics, – Seen as important in Philosophy since Plato. mineral resources, natural flora and fauna etc. But they are puzzling. Are we asking: – Then extended to cover land-use, farming, and other economic factors, even culture … – “When do we apply the word ‘X’?” or – Suppose one were now to ask “But is culture – “What is a genuine case of X?” really part of the discipline of geography?” The former seems merely linguistic; the – Well, if “geography” as actually used does latter – if different – can appear senseless. cover the study of culture, the answer is “Yes!”
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The Concept of Knowledge Intuitions, Puzzle Cases, and Conceptual Analysis Core normative concept, versus particular judgements: Conceptual analysis can involve: – The concept of “knowledge” plays a central role in – Appeal to linguistic “intuitions” (i.e. judgements distinguishing reliable beliefs from others. that we are naturally inclined to make). – This makes it normative: calling something – Puzzle cases (“intuition pumps”) that can put “knowledge” does more than just categorising it as pressure on those intuitions. something we standardly call knowledge. – Argument, in which we draw out implications of – Hence it does seem to be possible to ask these plausible judgements and principles. “Everyone calls this knowledge, but is it really?” – Systematisation, in which we try to clarify the – Compare the response to Strawson on induction: concept coherently in the light of all this. we call it reasonable, but is it really good evidence? 131 132 131 132
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Three Kinds of Knowledge The Traditional Analysis of Knowledge that P Acquaintance – “I know Oxford”, “Do you know John Smith?”. A subject (i.e. a person) S knows that P Knowing How if, and only if: – “I know how to drive”, “Do you know how to open – P is true this?” – S believes that P Knowing That, or Propositional Knowledge – S is justified in believing that P – “I know that this building is the Exam Schools”, A.J. Ayer gives the last two conditions as: “Do you know that it will rain?” – S is sure that P is true – Where P is the proposition concerned, this is often referred to as “Knowledge that P”. – S has the right to be sure that P is true 133 134 133 134
P is true Complications?
If S knows that P, does it follow that P Knowing Falsehoods? must be true? Distinguish two claims: – “I know that France is hexagonal” In a sense this can be considered true, because – S knows that P → P is necessarily true France is roughly hexagonal, but in that same false: I know that I exist, but it doesn’t follow that I sense, it is also true that France is hexagonal. exist necessarily. An Abomination – Necessarily ( S knows that P → P is true ) – Never confuse “P is true” with “P is believed to be convincing: We wouldn’t allow S’s belief that P to true”. Don’t say “P is true for me, but P is false for be counted as a case of knowledge unless the him” when what you mean is simply “I believe P, belief is, in fact, true. So it is a necessary truth that but he does not”. It was never true than the Sun anything known is true. orbits the Earth, even when everyone thought so! 135 136 135 136
S believes that P Knowing that One Knows
If S knows that P, does it follow that S Suppose that knowledge must always be believes that P? Not so clear: “conscious”. Then if I know that P, will it – Reliable guessing follow that I must know that I know that P? Suppose that I am not aware of knowing anything – The principle is tempting, but we can iterate … about some topic, but my “guesses” in a quiz are I know that P always accurate. I might be reported as knowing I know that I know that P P, even though I don’t believe P. I know that I know that I know that P – Blindsight I know that I know that I know that I know that P … Someone with blindsight has no conscious visual awareness, but can “guess” fairly reliably when – It is clearly impossible to have conscious belief asked to point towards objects. in all of this infinite sequence. 137 138 137 138
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
S is justified in believing that P The Regress of Justification
Perhaps the central role of the concept of Suppose that I believe that P, and this belief is to knowledge is to distinguish between beliefs be justified. Its justification will typically involve that are “secure” and those that aren’t. other beliefs. But then if P is to be justified, these other beliefs must be justified too, and so on … ? So what makes the difference between: How to prevent an infinite regress? We could take – believing that P (where P happens to be true) the whole web of interlocking beliefs as mutually – knowing that P? justifying in some way (coherentism), or else some “Surely”, if a belief that P is to count as a beliefs must be justified in a way that does not case of knowledge, it must be a justified depend on any other belief. Descartes was a foundationalist, taking some beliefs to be totally belief: one must have the right to believe it. secure. A more modern approach is externalism. 139 140 139 140
Internalism and Externalism Gettier Cases
An internalist account of justification requires all Suppose that: relevant factors to be cognitively accessible to S. – S is justified in believing that P. We’ll see that this faces difficulties … – P clearly implies Q. An externalist account (e.g. Armstrong, Goldman) allows that some factors relevant to judging S’s Does it follow that S, after inferring Q from justification (for belief that P) can be inaccessible P, is justified in believing that Q? to S; or external to S’s cognitive perspective. On internalist interpretations of “justified”, So justification could be a matter of a reliable this does seem to follow. But it leads to causal link between facts and beliefs. I might so-called “Gettier counterexamples” to the know that P (because my belief reliably depends traditional analysis of knowledge. on P’s truth) without knowing how I know. 141 142 141 142
A Gettier-style Counterexample “No Dependence on False Beliefs”
Should we add a fourth condition? For example, S knows that P if, and only if: – P is true – S believes that P – S is justified in believing that P … “There’s an oasis Real Oasis – … in a way that doesn’t depend on any falsehood Mirage over there” (out of sight) But this seems too strong. If you tell me “there were exactly 78 people there”, but you slightly S’s belief is true, and apparently justified, since he infers it miscounted (in fact there were 77), can’t I know from the (apparently justified) belief that he can see an oasis. that there were more than 40 people there, even But we would not say he knew that there’s an oasis there. though I’ve inferred this from a falsehood? 143 144 143 144
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
The Lottery Paradox Non-Accidental Truth
Another approach would be to understand To deal with the lottery paradox, it’s plausible justification as involving very high probability of to count a belief as knowledge only if it’s not truth (given the evidence available to S). an accident – not a “mere” matter of chance But then consider a billion-ticket lottery: (of whatever numerical degree) – that it’s true. – I believe that ticket 000000000 won’t win But how do we pin this down? – I believe that ticket 000000001 won’t win – Is it mere “chance” that my corroding speedometer is … still sufficiently reliable to provide an accurate reading – I believe that ticket 999999999 won’t win (when perhaps in a month’s time it won’t be)? Each of these is extremely probable, but we’re – Suppose I very occasionally hallucinate that P, is it reluctant to call any of them “knowledge”. So it “chance” that my current perceptual belief that P is not seems that no probability threshold will do. an hallucination? 145 146 145 146
Contextualism The Role(s) of the Concept of Knowledge Yet another problem, especially pressing for an “internalist” account of knowledge, is that Consider the contrast between: sometimes our criteria can vary. “Does she know that her husband is cheating – “I know that the train leaves at 17:36” (because I on her?” always take that train). which could just mean “Does she believe that he’s – “But do you really know that it does? It really is cheating on her, as we all do?” essential that I make that appointment.” “Do you know that her husband is cheating on – “OK, I’ll check on the Web to make sure. Then I’ll her?” know.” which is more likely to mean “Is it genuinely the This suggests that the “hurdle” for what counts case?”, rather than an epistemological enquiry. as adequate justification can vary. 147 148 147 148
Is “Knowledge” a Genuine Category? Back to G.E. Moore’s Hands
It is very unusual, in ordinary life, to ask If we agree with Moore, then we may see “Does S know that P” in a situation where: externalism about knowledge and – We are totally confident that S believes that P; justification as a way of reconciling his and claim that we know this is a hand, with the – We are totally confident that P is true. sceptical arguments that seem to show This might suggest that it’s a mistake to that we can’t know that we know. search for some single consistent account of An externalist can say to the sceptic: what “knowledge” is, which can deal with all “I can’t prove to you that I know this is a hand, the contexts in which it is applied. or that my belief is justified, but nevertheless I But we can still ask whether P is true … claim that I do know it, and it is justified.” 149 150 149 150
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Externalism and Scepticism Putnam’s Semantic Externalism
Suppose we accept an externalist account of The sceptic claims “I might be a brain in a justification. So if, say, my perceptual beliefs vat (BIV), so this hand might be just part of are, in fact, caused by a reliable causal the image created artificially.” process, then I do in fact know that this table But what do I mean by “hand”? According is in front of me. to Putnam, meanings aren’t purely mental. But of course the sceptic can still ask: “How If I am a BIV, then my word “hand” actually do I know – or if you prefer, what right do I means a “hand-in-the-image” … have to be at all confident – that my beliefs are in fact so caused?” Externalism does not … in which case this is genuinely a “hand”, exclude sceptical doubt “from the inside”. because it is a hand-in-the-image. 151 152 151 152
Sceptical Responses (1) (2) Post-Linguistic Envatting
Is the meaning of “hand” just determined by Suppose that I am “envatted” after I have what we’re actually referring to when we think become linguistically competent. we’re pointing to a real hand? So then my word “hand” has already Or do we have some further idea of the kind established its “outside vat” meaning. of thing that a hand really is? It seems to follow that when I later say “this Can we thus make sense of the possibility of is a hand” from within the vat, I can manage a “God’s eye view” (unavailable to us), from to mean a real hand rather than a mere which it would be clear that it is all a clever “hand-in-the-image”. If so, I can raise the simulation, rather than involving a real entity something like what we take a hand to be? question as to whether this really is a hand. 153 154 153 154
Back to Induction The Ethics of Belief
With vertical scepticism (evil demon, BIV, The Hume avoids indiscriminate scepticism by Matrix etc.), it’s tempting to ask in a semantic rejecting Descartes’ “ethics of belief” – the externalist spirit: “Why should I care if it’s all an view that we should withhold assent to illusion? I’m quite happy to continue with ‘life anything that’s not known with total certainty. as I experience it’ either way.” Hume sees belief as typically involuntary, so But Hume’s “problem of induction”, as a form of withholding assent isn’t even an option. horizontal scepticism, evades this response: Note that epistemological externalism also whether the world I experience is real or not, I involves a similar rejection. still have the problem of inferring from past to We seem to be forced to accept this, if we are future, from “observed” to “not yet observed”. to hold out against the sceptic. 155 156 155 156
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
General Philosophy The Mechanisms of Perception Dr Peter Millican, Hertford College The “mechanical philosophy” of Descartes and others had to explain perception in terms Lecture 6: Perception and the of particles (or waves) affected by the objects Primary/Secondary Quality distinction and in turn impacting on our sense organs. Most discussion focused on sight and touch, the two senses that seem to come closest to presenting external objects as a whole. Locke’s account was particularly influential, emphasising the primary/secondary distinction which had been implicit in Descartes. 158 157 158
What are Objects Like? Locke and Corpuscularianism
Mechanical explanations of perception imply Locke takes Boyle’s “corpuscularian that our impressions of objects are conveyed hypothesis” (IV iii 16) as plausible: by mechanisms whose stages (e.g. impact – Properties of substances arise from their of particles on our sense organs) bear no particular micro-structure: composed of resemblance to the objects themselves. “corpuscles” of “universal matter” (Boyle) or “pure substance in general” (Locke). The mechanical paradigm also suggests that – Underlying substance has primary qualities: objects’ fundamental properties will be those shape, size, movement etc., texture, and involved in mechanical interaction – i.e. “impenetrability” (Boyle) or “solidity” (Locke). geometrical and dynamic properties. – Secondary qualities (e.g. colour, smell, taste) are powers to cause ideas in us. 159 160 159 160
Pains, Colours, and Shapes A Problematic Text
Suppose a circular hotplate on an oven is Locke’s Essay, II viii 10: glowing red hot. I bring my hand close to “Such Qualities, which in truth are nothing in it and feel warmth, then pain … the Objects themselves, but Powers to produce various Sensations in us by their – The sensations of felt warmth and pain are primary Qualities, i.e. by the Bulk, Figure, clearly “in the mind”. Texture, and Motion of their insensible parts, – The circular shape of the hotplate is, we are as Colours, Sounds, Tasts, etc. These I call inclined to say, “really in the object”. secondary Qualities. – So is the red colour of the hotplate “in the The comma before “but” is unfortunate. mind” or “in the object”? Locke means “nothing … but powers”.
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Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
In Objects, or Just In the Mind? Why Resemblance?
Locke sees both PQs and SQs as genuine Hence Locke’s emphasis on resemblance, properties of objects, but the SQs are nothing rather than real existence in objects, as but powers due to their PQs. the key distinction between PQs and SQs: Berkeley read Locke as saying that SQs are only “the Ideas of primary Qualities of Bodies, are “in the mind” and not really properties of objects. Resemblances of them, and their Patterns do But Locke is clear that our simple perceptions of really exist in the Bodies themselves; but the objects’ colour etc. are “adequate”: they faithfully Ideas, produced in us by these Secondary represent their “archetypes” (II xxxi 1, 12): Qualities, have no resemblance of them at all. “Simple Ideas … are … certainly adequate. Because There is nothing like our Ideas, existing in the being intended to express nothing but the power in Bodies themselves.” (Essay II viii 15) Things to produce in the Mind such a Sensation …” 163 164 163 164
Can an Idea Resemble an Object? Structural Resemblance?
Berkeley (Principles I 8) is emphatic that: But ideas of PQs seem to lack this intimate “an idea can be like nothing but an idea; a connexion with mentality – they are more colour or figure can be like nothing but another abstract and structural, as illustrated by their colour or figure.” use in geometrical mechanics. His attack on Locke’s resemblance thesis We can use these “mathematical” properties seems to be based on the principle that to calculate predictions about objects’ ideas are intrinsically “perceivable”. behaviour, and find that these “work”. This is very plausible for SQs – nothing can So it’s plausible that ideas of PQs can be like a sensed smell, or colour, unless it is resemble non-mental reality in a structural mental (as with a felt pain). way (cf. Lowe on Locke, pp. 57, 63-4). 165 166 165 166
Solidity Hume’s Criticism (Treatise I iv 4)
However solidity seems to be an odd man “Two non-entities cannot exclude each other from out – our idea of solidity seems clearly to be their places … Now I ask, what idea do we form of these bodies or objects, to which we suppose the idea of a power (or rather, perhaps, the solidity to belong? To say, that we conceive them unknown ground of a power), and without merely as solid, is to run on in infinitum. … any resemblance to a property of objects. Extension must necessarily be consider’d either as colour’d, which is a false idea [because it’s a SQ, Solidity is a power – or a disposition – to supposed not to be “in” objects]; or as solid, which exclude other bodies. But what is a body? brings us back to the first question. … [Hence] Body is distinguished from empty space by after the exclusion of colours (etc.) from the rank of its solidity, so the whole thing is circular! external existences, there remains nothing, which can afford us a just and consistent idea of body.” 167 168 167 168
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Empiricism and Understanding The Attack on Abstraction
The attack on resemblance thus leads So Berkeley and Hume attack Locke on naturally to an attack based on our lack of the grounds that we can’t form a coherent understanding of the qualities concerned. idea of matter without using ideas of SQs. If all our ideas are derived from experience They see Locke as illegitimately trying to (as Locke had insisted), then our ideas of “abstract” a purely PQ idea of body away PQs (e.g. shape) will naturally be infused from our actual idea which is inextricably with those of the SQs by which we perceive bound up with perceptual notions. them (e.g. a colour that fills the space). Hence their focus on abstraction (see the And if these SQs cannot be understood as Introduction to Berkeley’s Principles). existing outside a mind … 169 170 169 170
The Case for Idealism “Something I Know Not What”
Berkeley concludes from To defend realism we should accept that our this argument that bodies idea of body is “inadequate” – we can’t independent of mind are conceive of what it is that fills space except literally inconceivable. in terms of “what it does” (cf. Essay II xxiii 2). If this works, it seems to More modern concepts such as mass and show that the only way we electric charge make this clearer: we are can make sense of the under no illusion that the basic properties world is as fundamentally consisting of employed in our scientific theories have to mental entities (i.e. “spirits” and “ideas”. be directly perceivable, or understandable in non-dispositional terms. 171 172 171 172
Locke’s Indirect Realism An Unacceptable Interpretation
Indirect realism is sometimes parodied as the view that in order to perceive a tree, I must perceive an image-of-a-tree (as though some sort of “homunculus” is sitting in my head viewing a little projector screen). Idea in the mind Material object However this clearly doesn’t explain (directly perceived) (cause of the idea) perception, because it presupposes that the The “Veil of perception” problem: how can we image-of-a-tree is itself perceived. If it can know whether there is a real material object? be “directly” perceived, why can’t the tree?
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Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Sense Data How To Prove the Causal Link?
Twentieth-century philosophers such as Ayer “It is a question of fact, whether the perceptions prefer the term “sense-data” to Locke’s of the senses be produced by external objects, “idea”, but this rather lends itself to the resembling them: How shall this question be unacceptable interpretation. determined? By experience surely … But here experience is, and must be entirely silent. The It’s better to say that awareness of a mind has never any thing present to it but the “sense-datum” counts as perception of an perceptions, and cannot possibly reach any external object if it was caused appropriately experience of their connexion with objects. The by such an object. supposition of such a connexion is, therefore, But how can I know that it was so caused? without any foundation in reasoning.” Again we face the “veil of perception”. (Hume, Enquiry 12.12) 175 176 175 176
Phenomenalism Direct Realism
Phenomenalism is the view that physical Rather than resort to phenomenalism, a objects are logical constructions out of more popular recent view (since J. L. sense-data. So statements about such Austin and P. F. Strawson) has been to objects are interpreted as stating what would insist that we perceive objects directly. be perceived in certain circumstances. – This seems right, in so far as it is intended to counter the Unacceptable Interpretation. – This aims to evade the Berkeleian argument that one cannot make sense of physical objects – However it doesn’t solve the sceptical problems, and can seem merely verbal: it is accepted that in abstraction from perceptions; our perception is mediated physically (by light – It also aims to answer the Humean argument of rays etc.); the point is just that we do perceive the veil of perception. objects (and see them as objects) by that means. 177 178 177 178
Is a Lockean View Defensible? Explanatory Realism
A live Lockean option is to see an “idea” as an Then Lockean “indirect” realism can be intentional object – the object as it appears (cf. defended as scientifically explanatory (in Mackie on Locke, pp. 47-51). line with its original motivation). This is purely mental, not any sort of image on a – How things appear to us is explicable in terms of screen (or a retina). Indeed it is not really any sort mechanisms involving external objects, physical of object at all. Nor is it an attempt to explain intermediaries etc. perception. The point is to insist that our visual experience (though only describable in terms of – These explanations appeal to objects’ “real” apparent objects) is in principle distinguishable qualities (which need not resemble our ideas) … from the existence of those objects. In that sense – … and explain illusions, both of SQs and PQs (to it is still a “representative” theory of perception. answer Berkeley’s argument from illusion).
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Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
General Philosophy The Problem of Free Will Dr Peter Millican, Hertford College We think of people as morally responsible for what they do “freely”. Lecture 7: Free Will – But we don’t blame them for what they are forced to do. Then we say they’re not free, and have no choice in the matter. Suppose that what I do is caused, or causally determined. – So it was causally necessary that I did what I did. How, then, can I properly be blamed?
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Determinism Taxonomy of Positions Determinism is the thesis that all events are “determined” by prior causes. So for any Is the thesis that we have genuine free will event E, given the causal laws that govern compatible with determinism? the universe, and the prior state of the world, – NO: Then at most one of them can be true … E was inevitable. We have free will; determinism is false – “[It is agreed that] matter, in all its operations, is = Libertarianism actuated by a necessary force, and that every We do not have free will; determinism is true natural effect is so precisely determined by the = Hard determinism energy of its cause, that no other effect, in such particular circumstances, could possibly have – YES: They are compatible = Compatibilism resulted from it. …” (Hume, Enquiry, 8.4). We have free will; and determinism is true – Hume thought this also true of human actions. = Soft determinism 183 184 183 184
The Consequence Argument “I Could (Not) Do Otherwise”
If determinism is true, then all human actions The traditional way of opposing the are causally determined consequences of consequence argument is to interpret the laws of nature and prior conditions. “I could do otherwise” differently. Instead Hence I cannot do otherwise than I actually of the incompatibilist’s reading: do, except by falsifying the laws of nature or – “It is causally possible, in that exact situation, changing past conditions. for me to do otherwise”, But clearly I can’t do either of these. the compatibilist will prefer something like: If I cannot do otherwise than I actually do, – “It would be possible for me to do otherwise in then I do not have free will. a similar (but not identical) situation in which I So if determinism is true, we lack free will. chose to do so”. So I can do as I choose. 185 186 185 186
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Frankfurt Cases Choice and “Could Do Otherwise”
Harry Frankfurt has argued that freedom Freedom seems very closely connected with doesn’t really require the possibility of doing the concept of choice, and this may lie otherwise (in either sense). behind the “could do otherwise” intuition. Suppose that I choose to go through door A – In the Frankfurt cases, I do make a choice, rather than door B, and accordingly do so. though in a sense I don’t have a choice. – This is a free action, even if it happens that But the notion of choice is quite slippery: (unbeknown to me) door B is actually locked, so – Suppose someone holds a gun to my head and I would have had to go through door A anyway. asks for my mobile phone: do I have a choice? This illustrates that what makes an action – Suppose a clever neuropsychologist can predict inevitable doesn’t always bring it about. that I’m going to hit you: do I have a choice? 187 188 187 188
“I had no choice” The Paradigm Case Argument
We must be very careful to distinguish: We learn the meaning of the word “choice” from – What happened was in no way dependent on my early childhood. To make a choice is, standardly, decisions or actions. to be presented with a range of alternatives – say – My actions were physically forced upon me. between ice cream, cake, and fruit – and then to select one according to our own preferences. – My actions were predetermined in some way by non-rational factors (e.g. drugs, brainwashing). This is a paradigm of what we mean by a choice. So it’s abusing words to deny that it’s a choice – My actions were predetermined by my own just because it’s determined. desires and consequent reasoning. – It was blindingly obvious what I should do (so Of course settling our use of words doesn’t decide “I had no choice” is rather like “it was no contest”). the important issues of determinism and moral responsibility, though it can remove confusions. 189 190 189 190
Hobbes’ Compatibilism The Contrastive Argument
Hobbes argues for compatibilism in a “Free” implies a contrast between acts that similar spirit, defining freedom in a very are not free, and those that are free. common-sense way that is entirely However the libertarian is mistaken to see compatible with determinism: this as the contrast between acts that are “LIBERTY, or FREEDOME, signifieth (properly) the caused and those that are uncaused. absence of Opposition (by Opposition, I mean Instead, the relevant contrast is between externall Impediments of motion;) … A FREE- MAN, is he, that in those things, which by his those that are coerced, compelled, or strength and wit he is able to do, is not hindred constrained, and those that are “free” of to doe what he has a will to.” such influences.
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Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Freedom and Responsibility Ayer and Hume
The Contrastive Argument seems quite Ayer, like Hobbes, uses the Contrastive persuasive, because it aims to link free Argument: will with moral responsibility. “For it is not, I think, causality that freedom is to It seems plausible that I can be absolved be contrasted with, but constraint” of responsibility for something if: (“Freedom and Necessity”, in Watson, p. 21) – I didn’t do it at all. Hume is often thought to use the argument – I was compelled to do it. also, but in fact he does not. – I was coerced into doing it. (His Treatise contrasts “liberty of indifference” with “liberty of spontaneity”, and this has misled in short, if I didn’t do it freely many commentators.) 193 194 193 194
Hume’s Notion of “Liberty” Three Concepts of Freedom
Hume’s definition is in fact significantly 1. Contra-causal, libertarian free will different from those of Hobbes and Ayer: (opposed to determinism). “By liberty, then, we can only mean a power of 2. Intentional agency; that in virtue of acting or not acting, according to the which a person is an agent in respect of determinations of the will; that is, if we choose what he or she does. to remain at rest, we may; if we choose to move, we also may. Now this hypothetical 3. The absence of unwelcome restrictions liberty is universally allowed to belong to affecting choice of action (e.g. coercion, every one, who is not a prisoner and in compulsion, or an influence that is chains.” (E 8.23) resented by the agent).
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“Give Me the Money, Or Else!” Four Ways to Leave a Lecture
If I work in a bank, and someone takes my Contrast four possible situations: family hostage and threatens to murder – Someone forcibly binds me, and carries me them unless I open the safe, I am acting out of the lecture theatre (I am like Hume’s under coercion but still acting from choice. “prisoner and in chains”). – I choose to open the safe given this situation. – Someone threatens to shoot me unless I abandon the lecture, so I obey. So I am morally responsible for what I do, but what I do is the right thing (in that – I have a blind panic at the thought of giving the lecture, and run out in confusion. situation). I do not need to plead – I realise my lecture is going really badly, so I diminished responsibility to avoid blame. pretend I’m ill and leave early.
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Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Clarifying the Options Hume’s Distinctive Contribution
In the first case (bound and carried), my leaving If “liberty” is a matter of our actions’ following the lecture is not even an action of mine; it is our will, then we do have such liberty, even if something that is done to me. our will itself is causally determined. In the second case, I leave of my own choice, So Hume’s definition of “liberty” makes it and this is the right thing to do. compatible with determinism. In the third case, I have done something wrong Hume’s most distinctive contribution is to (abandoning the lecture), but there are provide a novel argument for the determinism mitigating circumstances. of human actions, appealing to the In the fourth case, I am fully responsible for understanding of “necessity” reached in leaving, and significantly at fault. Enquiry Section VII. 199 200 199 200
Applying the “Definitions of Cause” Satisfying the Two Definitions
“Our idea … of necessity and causation arises To prove his case, Hume must show that human entirely from the uniformity, observable in the actions satisfy the two “definitions of cause”. So operations of nature … Beyond the constant most of Section VIII Part i is devoted to arguing: conjunction of similar objects, and the consequent – that human actions manifest such uniformity; inference from one to the other, we have no notion – that they are generally recognised as doing so; of any necessity, or connexion.” (E 8.5) – that people standardly draw inductive inferences “If these circumstances form, in reality, the whole accordingly, just as they do about physical things. of that necessity, which we conceive in matter, and Hence “all mankind … have … acknowledged the if these circumstances be also universally doctrine of necessity, in their whole practice and acknowledged to take place in the operations of reasoning”, even while “profess[ing] the contrary the mind, the dispute is at an end.” (E 8.22) opinion” (E 8.21). 201 202 201 202
Why Is Determinism Denied? Morality requires Determinism?
People deny the determinism of human actions Hume then goes on to argue (E 8.28-30) that in part because they have viewing human behaviour as causally “a strong propensity to believe, that they penetrate determined, so far from being contrary to farther into the powers of nature, and perceive morality, is actually essential to it, since blame something like a necessary connexion between the cause and the effect” (E 8.21). and punishment are useful and appropriate only where actions are caused by the agent’s durable On Hume’s account such penetration is just a character and disposition. seductive illusion. And in learning that the necessity of physical operations amounts to no Requiring complete determinism may be going more than constant conjunction and consequent too far, but the argument has a point: it’s hard to inference, we come to see that human actions see how “free will” can be morally relevant if it too are subject to the same necessity. simply involves an element of randomness. 203 204 203 204
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Is Free Will Incoherent? Morality as Founded on Sentiment
On either account, it can seem hard to Hume’s way of squaring determinism with spell out a coherent notion of free will: morality is based on his sentimentalism: – The challenge to the determinist is to explain A man, who is robbed of a considerable sum; does he find his how I can be genuinely responsible for what I vexation for the loss any wise diminished by these sublime reflections? Why then should his moral resentment against the do, if every detail of my behaviour was “pre- crime be supposed incompatible with them? (E 8.35) ordained” before I was born. Morality is founded on emotions that naturally – The challenge to the libertarian is to make arise within us in certain circumstances, so we sense of free will in a way that is neither shouldn’t expect these emotions to disappear determined nor merely random. (Some have just because we reflect on the inexorable chain tried to respond in terms of “agent causation”, though the notion is very obscure.) of causation which led to the criminal’s action. 205 206 205 206
Freedom and Autonomy Higher-Order Desires
Though Hume is able to accommodate Harry Frankfurt distinguishes between “first- morality within his approach, it may seem order” desires (e.g. to smoke a cigarette) too crude, in treating freedom as simply a and “second-order” desires (e.g. to quit matter of “power to act as we will”. smoking, and to cease to desire them). There seems to be a significant difference If one’s second-order desires are unable to between those who are autonomous – able overcome first-order cravings, then one is to control their will to some extent – and not fully autonomous and thus less “free”. those (such as drug addicts or obsessives) Thus a determinist can consistently who are, in a sense, “slaves to their will”. distinguish various degrees of freedom.
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Kane on Indeterminism Why Does Indeterminism Matter?
Robert Kane: Kane argues that through such indeterminist http://www.ucl.ac.uk/~uctytho/dfwVariousKane.html choices over the course of our lives, we forge addresses these issues from an indeterminist our own character, and this makes us perspective. He points out that an element of responsible even for those actions that are fully randomness is compatible with responsibility. determined by our formed character. – e.g. suppose that I try to shoot someone, but my The difficulty for Kane is in explaining why aim is unsteady. If I succeed, then I am clearly indeterminism – an element of genuine responsible, despite the element of randomness. randomness – makes a difference here: – Likewise, if it is chancy which intentions within my – What’s so valuable about randomness? mind will dominate on some occasion, this is quite – If unpredictability is what matters, wouldn’t compatible with responsibility for whichever “wins”. deterministic “chaos” do just as well? 209 210 209 210
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
General Philosophy Personal Identity Dr Peter Millican, Hertford College Distinguish two questions: – What is it to be a person? Lecture 8: Personal Identity This invites a discussion of mind and body etc. – What is it for a and b to be the same person? This raises the issue of personal identity Another important distinction: – Sameness = qualitative similarity – Sameness = numerical identity Often best to avoid the words “same” and “identity”. Instead say “similar” or “one and the same”. 212 211 212
Leibniz’s Law Again Cross-Temporal Identity
If a and b are the same thing, then any We thus avoid the fallacy – most famously property of a must also be a property of b: made in Hume’s Treatise – of supposing that Fa, a=b ╞ Fb strict identity (“one and the sameness”) over time implies exact similarity over time. Let a = Peter Millican as a baby. b = Peter Millican today. But this still leaves the question of what F = “weighs less than a stone”. constitutes personal identity over time: is it physical constitution, or immaterial substance, – We have Fa, ¬Fb, hence apparently ¬(a=b) ?! or organic life, or psychological continuity? – This can be dealt with by specifying F more This is not the same as asking how we judge precisely: “weighs less than a stone in 1958” or “weighs less than a stone in 2009”. personal identity in practice (e.g. by the body). 213 214 213 214
Locke on the Identity of Matter Sorites Arguments
The appropriate criterion of identity over A sorites argument is one that depends on time depends on the kind of thing it is: iteration of a small variation, for example: – A single particle of matter retains its identity as A man with just 1 hair is bald. long as it continues in existence. So a and b If a man with just n hairs is bald, then a man are the same particle of matter if there is a with just n+1 hairs is bald too. continuous history connecting them. A man with 1,000,000 (etc.) hairs is bald. – The identity of a body of matter depends on the identity of the particles that constitute it. It’s the If we try to relax Locke’s strict criterion of same body iff it’s the same collection of bodily identity, we run into this problem: particles, even if differently arranged. (However – Remove 1 atom from a body, and it’s still the this too seems to require a continuous history.) same body … 215 216 215 216
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Locke on the Identity of Organisms Locke on Personal Identity
A plant or animal is not a mere collection A person is “a thinking intelligent Being, of matter, but “an Organization of Parts in that has reason and reflection, and can one coherent Body, partaking of one consider it self … the same thinking thing Common Life” (Essay II xxvii 4). in different times … which it does only by Hence the identity of an organism over that consciousness, which is inseparable time is constituted by a continuous history from thinking … and … essential to it” (9). of such an organised life. Hence personal identity over time is a Likewise the identity of a man or woman: a matter of continuity of consciousness human is a living organism. (which depends on memory).
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Personal Identity as “Forensic” Reid’s Problem Case
Personal identity concerns morality, desert, Suppose that a young lieutenant can reward and punishment etc. Hence Locke remember what he did as a child, and the wants to avoid any dependence on identity of later general can remember what the immaterial substance (which may be turned lieutenant did but not what the child did. over like bodily substance, for all we know). It seems that according to Locke we have: Williams’ thought experiment: L = C – Suppose your brain is to be switched with mine, G = L after which various things will befall “us”. Which G ≠ C future person are you more concerned about, But identity is transitive, so this is inconsistent. my-body-your-brain, or your-body-my-brain? 219 220 219 220
The Ancestral Relation Memory and Quasi-Memory
x is an ancestor of y if either: One problem with basing personal identity – x is a parent of y; on memory is that something only counts – x is a parent of an ancestor of y. as a genuine memory if it concerns one’s We can generalise this: “ancestor” is the own experiences. Suppose I wake up “ancestral” relation of “parent”. apparently remembering your experiences: would this count as a memory? If not … Reid’s problem can be avoided if personal identity is based not on direct memory, but – the criterion is circular: I have to know that it was really me to know that it’s a real memory; on its ancestral relation, “memory chains”. – instead, we can talk of “quasi-memory”, that is, However lots of other problems remain … apparent memory. 221 222 221 222
Peter Millican, Hertford College, Oxford, MT 2009 General Philosophy 1 & 2: Historical Background
Sleep, Coma, Forgetfulness Human Animals
Another problem is that our memory and Since we are animals, it is tempting to consciousness do not seem to be identify personal identity with the identity continuous. We sleep, forget, and can of the human organism. even lapse into coma before recovering. However this has significant implications: All this suggests that some element of – If I was once a fetus (the same human bodily (or at least brain) continuity is organism as me), then it seems to follow that I desirable, to “bridge over” the gaps in was once not a person (which seems to conscious awareness or memory. But require some significant mental life). might bodily continuity be sufficient? – So being a person is an accidental property of mine, rather than an essential property. 223 224 223 224
Relying on the Brain Split Brains
An amalgam of the two views is to identify But things are not so simple. If the nerves the person with the developed functioning between the cerebral hemispheres are brain rather than the whole organism. surgically cut (a procedure called This removes the problem of seeing a tiny commissurotomy), then a single brain can give rise to two conflicting behaviours – for embryo as a person. example, two hands doing different things! It also makes sense of the Williams case: Now suppose that a single brain were split if our brains are swapped between our and put into two bodies: we could have two bodies, then I’m personally concerned new persons, both having brain and memory about the future of my-brain-your-body. continuity with the original person.
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What We Should Care About “Open Texture”
Maybe if this happened, we’d give up the Friedrich Waismann coined this term for notion of strict personal identity. Maybe, concepts which become vague in radically as Parfit suggests, we should instead treat novel situations: straightforward application it as a matter of degree. depends on things being generally normal. If what matters is our concern about our For example, can a man “marry” a sex- future self (or selves), then this seems to changed woman (or a sex-changed man)? reflect the way we would judge about a This suggests there may be no right answer split brain case: we care about the future to some puzzle cases: if they occurred, of both future invididuals. conceptual innovation would be required.
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Peter Millican, Hertford College, Oxford, MT 2009