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Phil 30302-01 History of Modern Philosophy

Spring 2012

Part I

Professor Marian David

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Old Worldview

• Pythagoras; Eudoxus and Aristotle (c. 350 BC); Ptolemy (c. 150 AD)

• Geostatic and Geocentric

• Two realms: the Heavens and the Earth—absolute division.

• Earth (sublunar)– is a globe (Pythagoras, Erathostenes (c. 200 BC)) at rest and at center of

universe; 4 elements (earth, water, fire, air): change, decay, imperfection.

• The Heavens (supralunar)– are transparent crystalline spheres revolving around center (for fixed stars and

for each planet); all force comes from outside (from prime mover); heavenly things made from 5th element (the quintessence): perfection, no change, only perfect motion = circular motion (Pythagoras)

• Epicycles – needed to explain retrograde motion of planets consistent with uniform circular

motion.

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Readings for Thursday, January 19

• How did Erathostenes figure out the circumference of the earth?

• Read about: The Scientific Revolution

– Wikipedia

– The Stanford Encyclopedia of Philosophy

– …

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The Scientific Revolution

• 1610 – 1687

• Where does it come from?

– 6th to 11th cent: Dark Ages; Anti-intellectualism; the 1000-Years story

– 12th & 13th cent: Beginning of rediscovery of Ancient Science, partly through Arabic channels

– 14th & 15th cent: Rediscoveries sink in; the Renaissance begins (early 15th to late 16th)

– 16th & 17th cent: The great artesans, e.g. Leonardo da Vinci (1452-1519); mathematics, esp.

geometry; the Scientific Revolution

Anti-Intellectualism in (Early) Christianity

For it is written: “I will destroy the wisdom of the wise; the intelligence of the intelligent I will frustrate.” (Isa 29.14) Where is the wise person? Where is the teacher of the law? Where is the philosopher of this age? Has not God made foolish the wisdom of the world?

Paul, Corinthians 1.19–20

The Son of God was crucified: there is no shame, because it is shameful. And the Son of God died: it is wholly credible, because it is unsound. And, buried, He rose again: it is certain, because impossible.

Tertullian: De Carne Christi, V.4.

When, then, the question is asked what we are to believe in regard to religion, it is not necessary to probe into the nature of things, as was done by those whom the Greeks call physici; nor need we be in alarm lest the Christian should be ignorant of the force and number of the elements,—the motion, and order, and eclipses of the heavenly bodies; the form of the heavens; the species and the natures of animals, plants, stones, fountains, rivers, mountains; about chronology and distances; the signs of coming storms; and a thousand other things which those philosophers either have found out, or think they have found out…It is enough for the Christian to believe that the only cause of all created things, whether heavenly or earthly, whether visible or invisible, is the goodness of the Creator, the one true God; and that nothing exists but Himself that does not derive its existence from Him…

Augustine, Enchiridion, 9.

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Scientific Revolution (17th century)

• Three Central Innovations:

I. The Heliocentric and Geodynamic Worldview

II. Law of Inertial Motion

III. Atomism and Mechanism

• II & III: New physics of motion and matter.

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I. Heliocentric and Geodynamic Worldview

– Aristarch of Samos (c. 250 BC); Copernicus, Tycho Brahe, Kepler, Galileo, Newton

• Sun at center of planetary system.

• Earth is in daily and annual motion.

• No fundamental divide between heavens and earth.

– 1543: N. Copernicus: On the Revolutions of the Heavenly Spheres Andreas Vesalius: The Structure of the Human Body

– 1609: J. Kepler: Astronomia Nova• Planets’ paths are elliptical; Kepler’s laws

– 1610: Galileo: The Messenger from the Stars • Telescope: Many stars Milky Way; Moon is imperfect; Venus has true phases and changes apparent size;

Moons of Jupiter

– 1644: Descartes: Principles of Philosophy

– 1687: Isaac Newton: The Mathematical Principles of Natural Philosophy• Classical physics of matter and motion; subsumes Astronomy; highly mathematized, axiomatic system

• New picture goes radically against observation and common sense!

– Observed motions are illusions!

• Observational evidence for new view is actually rather thin.

• What supports the new view?

– Simplicity: It provides a better explanation of the data; no epicycles

– Okay fit with data

– Phases of Venus: only direct observational evidence against old view

– Galileo’s defense against objections

• Serious problem: no stellar parallax observable

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Readings for Tuesday, January 24

• Modern Philosophy

– Francis Bacon: New Organon

– Galileo Galilei: The Assayer

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II. Law of Inertial Motion

• Galileo (circular); Descartes (rectilinear); Newton

• The law becomes the cornerstone for entire modern physics—its final formulation by Isaac Newton (1687):

– “Every body perseveres in its state of rest, or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed thereon.”

• Inertia conflicts sharply with Aristotle’s physics

• Aristotle: natural vs. violent motion:– Its natural motion is intrinsic to an element

– Violent motion requires an external force

– Generates serious problems: law of inertia dissolves them

– Medieval precursor to law of inertia: John Buridan’s impetus theory

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• Galileo – famously uses inertia to respond to common sense objections to Copernicanism

– applies same laws of motion to planets and earthly bodies against Aristotle’s divide

– relies heavily on idealizations and thought experiments

– real experiments and observations are used only for testing his views

– Compare Plato, Republic, 530b: “Then if, by really taking part in astronomy, we’re to make the naturally intelligent part of the soul useful instead of useless, let’s study astronomy by means of problems, as we do geometry, and leave the things in the sky alone”.

• Anti-Empiricist tendencies: The new physics goes against common sense and observation:– Appearances are misleading and need to be corrected by reason

– Observation vs. theory

– Appearance vs. reality

– Undermines trust in God-given senses? but intellect is God-given too?

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III. Atomism and Mechanism

• Reductive Atomism– Democritos (c. 400bc), Epicurus (341-270bc), Lucretius (c. 50bc, De rerum naturae)

– All matter is ultimately constituted by tiny indivisible material particles = atoms.

– Ancient atomism arose from debate about constancy through change: “All there is are atoms and the void” (Democritus); change is rearrangement

– Aristotle was no atomist!

– New science wants to offer reductive explanations: Big things are aggregates of little things; properties of big things can be explained by properties of little things.

• Mechanistic Philosophy: – Physical world = particles of matter in motion, governed by mechanical laws– Law of inertia is basic– Bodies change direction on impact with other bodies– Nature explainable in terms of laws (mathematizable) governing the motion of particles– Model: mechanical clockwork

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Galileo Galilei (1564-1642)

• Atomism seems non-empirical– Atoms are not observable

– Deep structure of reality very different from how it appears

– Sensible qualities of things are mostly illusions

– Galileo: “Heat is motion”!! Primary and secondary properties

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• 1610: Galileo’s The Starry Messenger

• 1616: The Congregation of the Holy Office agrees on censures of the following two propositions:

1. The sun is at the center of the world and hence immovable of local motion.

2. The earth is not the center of the world, nor immovable, but moves according to the whole of itself, also with a daily motion.

– Proposition 1 is “foolish and absurd in philosophy and formally heretical, since it explicitly contradicts in many places the sense of Holy Scripture, according to the literal meaning of the words and according to the common interpretation and understanding of the Holy Fathers and doctors of theology”.

– Propositions 2 “receives the same censure in philosophy and…in regard to theological truth it is at least erroneous in faith”.

– [Compare, e.g., Joshua 10: 12-13; Psalms 104: 5; Ecclesiastes 1: 4-5]– [Reference: Opere di Galileo Galilei, ed. A. Favoro, Florence 1890-1909]

• 1616: The Congregation of the Index of Forbidden Books puts Copernicus on the Index saying that Copernicanism is “contrary to Holy Scripture”, which does not, by itself, imply a theological censure. Galileo’s book itself is not put on Index, but he is admonished not to hold, teach, or defend these opinions.

The Galileo Affair

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• 1623: New Pope (Urban VIII): Can Galileo (or Kepler) demonstrate the truth of the Copernican hypothesis?

• 1633: Galileo’s Dialogue on the Two Chief World Systems (1632) is put on the Index, together with “all such works”.

• 1633: The trial of Galileo: he is “vehemently suspect of heresy… having held and believed a doctrine which is false and contrary to Holy Scripture” Galileo recants officially House-arrest. (Descartes ditches The World.)

• 1740s: Copernicus, Galileo, Descartes stay on Index but reference to “all such works” is dropped.

• 1830s: Copernicus, Galileo, and some of Descartes silently dropped from Index.

• 1917: Index is disbanded.

• 1972: Pope John Paul II. orders re-evaluation of Galileo’s trial.

• 1998: Results: “…misunderstandings on both sides”.

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Rationalism vs. Empiricism (rough)

• An ongoing debate.

• Rationalism:

There is knowledge that is independent from sense perception; there is a priori knowledge.

– Rationalists claim that a priori knowledge is the best, most certain knowledge we have (models: Math & Logic).

– Some rationalists (e.g. Plato) are tempted to claim that a priori knowledge is the only real knowledge:

• Radical rationalism: All knowledge is a priori.

• Empiricism:

All knowledge derives from/depends on sense perception; there is no a priori knowledge.

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• Rationalists

– need to give examples of alleged a priori knowledge;

• definitions, • basic logical & mathematical principles,• basic metaphysical and/or scientific principles,

– need a story about the origin of a priori knowledge

• traditionally, they turn to

• Innatism, a.k.a. Nativism: A priori knowledge is innate.

– Plato’s version (Meno 81c-d, 85d-86c)

• The soul was in possession of truths before birth; • What we call “learning” is really recollection (anamnesis);

– Other versions:

• Innate endowments come from God, at conception; or• Innate endowments come from evolution, at conception.

• Alternative to Innatism ?– Divine Illumination

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Readings for Thursday, January 26

• Modern Philosophy Anthology

– Francis Bacon: New Organon

– Galileo Galilei: The Assayer

• Internet, et al.

– The Mechanistic Philosophy (Mechanism)

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New Science and Epistemology

• Anti-Empiricist diagnosis of New Science: Don’t trust sense experience!

– Push towards rationalism

– Mathematization of Science

– [An exaggeration, overreaction?]

• Sir Francis Bacon, Lord Verulam (1561-1626)

• Lord Chancellor of England, under James I

• He was as a Shakespeare candidate

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Francis Bacon (1561-1626)

• “Knowledge is power”

• Strongly against Aristotelian tradition

– which doesn’t necessarily mean against Aristotle

• Need for a new science (“new is good”—a new idea)

• Radical empiricist approach to science

– Inductive method: use observation and experiment to collect data, then formulate general causal laws (“axioms”) explaining old data and predicting new data → Bottom up approach, leads to interpretations of nature

– Against Aristotelian “induction” and against rationalism (anticipations of nature)

– He was opposed to much of the scientific revolution because he thought it was too theory driven (too top down, using observation and experiment only for testing) !

• More influence later, e.g. on British Empiricism

• But he stands apart of the scientific revolution

Francis Bacon

• Idolatry

– Critique of cognitive biases and malfunctions, of prejudices, of distorting influence of language

– Some very up-to-date features: Contemporary cognitive science

– Sections 41, 45, 46.

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Readings for Tuesday, January 31

• Anthology

– Intro to Part 1: Descartes’ Meditations and Associated Texts

– Descartes: Meditations On First Philosophy

• Letter of Dedication

• Meditation One

• Meditation Two

• Meditation Three, to p. 49b, 2nd paragraph

– Montaigne: Apology

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René Descartes (1596-1650)

• French catholic

• Mathematics!

– Cartesian Coordinates

• Physics!

• Biology

• Philosophy!

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Meditations on First Philosophy (1642)

Letter of Dedication

• God and the Soul are proper subjects for philosophy (science) not just for theology.

– Lateran Council

• Geometry

– held up as model of certainty

• Withdrawal from the senses!

– partly a reaction to scientific revolution

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Meditation I

• Goals

– avoiding false beliefs & attaining true beliefs

– a stable belief system: certainty

• Method of Doubt (MoD):

– Search for indubitable first principles (foundations of knowledge) by way of doubting one’s opinions:

– Retain only those opinions whose truth is indubitable, discard all others!

• MoD attacks the reliability/trustworthiness of the senses!

– P. 41a: “Surely…”.

– Compare medieval slogan: “Nothing is in the intellect that was not previously in sense” (Nihil est in intellectu quod non prius fuerit in sensu); e.g. Aquinas, De Veritate, Q.2, A.3.

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• Three reasons for doubting beliefs based on sense perception:

1. Senses are sometimes deceptive [not very strong]

2. Dream Argument

3. Evil Demon Argument

• General Structure of D’s arguments:

I could have the same sense experiences I am having now, even if all my perceptual beliefs were false, see 1, 2, 3.

Therefore:

My perceptual beliefs are not indubitable; they don’t pass the MoD test.

• Upshot of Med I:

– “But eventually…”; p. 42b, 1st para.

– None of my beliefs about the world are indubitable.

– Nothing is certain?

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• D’s skeptical hypotheses (reasons for doubt) throw in-principle doubt on our beliefs about:

– material things (bodies)

– your own body (including brain)

– other persons (including God)

– the past

• Cartesian Doubt is radical.

– Note however: D does not say that our ordinary opinions are false;

– He does not even say they are not reasonable or not probable; see marg. 22.

• Does he actually doubt these things?

– P is not doubted ≠ P is indubitable

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• Skeptics (historical):

– They doubt that we have any knowledge about the world

– Various ancient schools from Greeks up to late antiquity:

• Academic Skeptics and Pyrrhonists (Sextus Empiricus: Outlines of Pyrrhonism, c. 150 a.d.)

– Goal: agnosticism (= withholding judgment) to achieve peace of mind

• Descartes’s Methodological Skepticism:

– Doubt as a method to reach indubitable truths

– Hyperbolical doubt → probability is not good enough: certainty

– Motivated by perceptual illusions

– Motivated by upheaval in the sciences!

– Descartes wants to build the new science on firm foundations so that it cannot suffer the same fate as the old science.

• Anti-Empiricist Diagnosis of Sci. Rev.: Don’t trust sense experience!!

Concerning the gods, I have no means of knowing whether they exist or not or of what sort they may be. Many things prevent knowledge including the obscurity of the subject and the brevity of human life.

Protagoras, Concerning the Gods (5th cent. b.c)

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Meditation II

• Descartes finds some indubitable truths: the Cogito (43b):

• Cogito ergo sum = I think, therefore, I am

I exist

I think

• When I am thinking that I exist, then what I am thinking is true.

When I am thinking that I am thinking, then what I am thinking is true.

• When I am thinking that I don’t exist, then what I am thinking is false.

When I am thinking that I am not thinking, then what I am thinking is false.

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• What am I?

– that is: What is a person?

– Method of Doubt reapplied to this question.

• Aristotle: A person is a body + a soul.

vegetative sensitive intellectual (noûs)

(Three aspects/parts of the soul)

• Descartes: – Am I a body? ☹ doubtful

– Am I a soul? a vegetative soul? ☹ a sensitive soul? ☹

an intellectual soul (noûs)? ☺☺☺

• I am a thing that thinks!

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Descartes’ Definitions

• x is a mind = x is a thinking thing

– that is, a thing that doubts, understands, affirms, denies, wills, refuses, and also imagines and senses…(45a; later also: feels)

– broad notion of thinking

• x is a body = x is an extended thing

– extended in three dimensions

– broad notion of a body = a material thing

• Note well:

– Descartes has not argued (yet) that he is not also a material thing: as far as he knows (so far), he could still be a body! (44b)

– “I am not certain that I am a body” ≠ “I am certain that I am not a body”

– Aristotle

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Readings for Thursday, Feb 2

• Anthology

– Descartes: Meditations On First Philosophy

• Med. Two, “The Wax Argument”, pp. 45b to end

• Med. Three, to p. 49b, 2nd paragraph

– Third Set of Objections: Hobbes vs. Descartes

• Against Meds I & II

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Descartes’ Program (?)

• “I think” and “I exist” serve as the most basic axioms:

– absolutely certain and indubitable, known by intuition,

– but not necessary truths: they are contingent,

– but not universal truths: they are about myself.

• Show that axioms about my self (my own mind) serve as foundations for all my knowledge about the world—to the extent that I have such knowledge.

– Model: Euclid (see D’s introductory letter)!

– Note that only Euclid (and Logic) survived the scientific revolution!

• Only two axioms?

Necessary truth: a proposition that is true and could not possibly be false;

Contingent truth: a proposition that is true but could have been false.

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• More axioms (45a, 3rd para):

My beliefs about my own mental states, that is, my beliefs about the present contents of my own consciousness:

– My beliefs about how things appear to me now;

– My beliefs about how I feel now (about my pain, pleasure, etc.);

– [My beliefs about my own present beliefs, doubts, desires;]

– That is, my beliefs about my present “modes of thinking” (c.f 47b).

• All of these beliefs of mine are indubitable– They can serve as foundations for my knowledge about the world (if any),

– or so D seems to maintain.

• My knowledge about the present contents of my consciousness does not come through sense perception!

– I do not see with my eyes (smell, taste, hear, touch) the contents of my consciousness.

The Wax-Argument

• Med 2, pp. 45b to end.

• What’s going on there?

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Meditation III (First Part)

• The Rule: Whatever I understand very clearly and distinctly is true.– D says “perceive”

– D gets to this rule by reflecting on Cogito and MoD

– D wants to use it to derive theorems from his axioms

– clear & distinct ≈ what survives the MoD

• Problem:

– I used to think that sense perception is clear & distinct, but MoD showed it isn’t.

↓

• Analysis of sense perception into two aspects:

– Ideas and the judgments we make (beliefs we form) based on our ideas.

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Descartes’ Theory of Ideas: A.k.a. The Representational Theory of the Mind

– The mind is a thinking thing.

– Thinking is the processing of ideas.• Ideas are “modes of thinking”.

– Ideas are “the stuff” thoughts are made of: parts of thoughts.

– Ideas are mental representations of things and properties.• “…because ideas can only be, as it were, of things” (Med III, 51a)

– They mediate our access to the world (if any).

– Ideas are objects of immediate awareness.• An idea is “whatever is immediately perceived by the mind”.

• Distinguish complete thoughts from ideas:

– The thought THAT GOD EXISTS vs. the idea GOD; the idea EXISTENCE.

– The thought THAT I HAVE A HAND vs. my idea of MYSELF; my idea of my HAND.

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“I can have no knowledge of what is outside me, except by means of the ideas I have within me.”

Descartes

“Human souls perceive what passes without them by what passes within them.”

Leibniz

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• Sense Perception – is indirect, inferential: it involves making tacit judgments:

– When I “see” that there is a grey cat, I am directly aware of my grey-cat idea; based on that I judge that there is a grey cat in front of me;

– Normally, I trust that my grey-cat idea is an accurate representation of reality.

• Naïve Assumption of Accuracy (47b, 48b-49b):

Our naïve trust in the reliability of sense perception relies on the two-fold assumption that our ideas accurately represent an external world, i.e.,

• (i) that our ideas are caused by external objects;

• (ii) that the external objects that cause our ideas also resemble them.

• This assumption is a natural one to make:

– But is it right? Is it just a “blind impulse”, or is it reasonable?

– How can it be vindicated?

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The Problem of Our Knowledge of the External World

1. I have indubitable knowledge of my own existence and my own mind (that is, of the present states of my own consciousness, of my present ideas);

2. Based on this, how can I demonstrate (prove):

– that there are material things (including my own body)?

– that there are other minds (including God)?

– that there was a past?

• external: to consciousness, not to my body or my skin or my skull.

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Some Remarks

• Descartes’ strategy in the rest of Meditations:

– prove that God exists;

– prove that He is not a deceiver;

– then use this to tackle the external world problem.

• Descartes sets agenda for modern philosophy:

– Knowledge of internal world is available;

– How do we get knowledge of external world? How do we get outside the theater of our own ideas?

– Philosophers after Descartes all accepted the underlying framework: the theory of ideas (the representational theory of the mind).

– But few believed that his specific strategy for tackling the external world problem would be successful.

– Main difficulties: God and causation.

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Readings for Tuesday, Feb 7

• Anthology

– Descartes: Meditations On First Philosophy

• Med. III, from p. 49b 3rd to end

– Preface to the Reader, 38a 2nd

– The Meditations arranged in “Geometrical Fashion”, 72a–75b

– Third Set of Objections: Hobbes vs. Descartes

• Against Med III

• Item 2 on Concourse

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• The word “Idea”– Plato

– Neoplatonism and Augustine

– Descartes

• Descartes on Ideas, in Reply to Hobbes (79b-80a):

– The word “idea” is not “to be understood to refer exclusively to images that are of material things and are depicted in the corporeal imagination”

– “I point out hat I take the word “idea” to refer to whatever is immediately perceived by the mind”

– “I used this word because it was common practice for philosophers to use it to signify the forms of perception proper to the divine mind, even though we acknowledge that there is no corporeal imagination in God.”

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Meditation III (Second Part):Descartes’ Trademark Argument for God’s Existence

• Two closely related arguments in Med III:

– Page 49a to 52b 1st para – Page 52b 2nd para to 54a

• An argument for the existence of God?

– Catholic Dogma: God, our Creator and Lord, can be known with certainty, by the natural light of reason from created things (De fide.)*

• Compare Descartes and St. Thomas:

– Both employ causation;– But Descartes starts with a premise about his own mind: “I have an idea of God”.

* Ludwig Ott, Fundamentals of Catholic Dogma, (Tan Books 1960), p. 13.

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• Distinguish the idea of X from X!

– My idea of the sun ≠ the sun

– My idea of my wealth ≠ my wealth

• One cannot, in general, prove the existence of X from the idea of X!

For most X: I have an idea of X

X exists is invalid ☹☹☹

• Are there any special Xs for which this sort of argument is valid (special cases)?

– Yes: X = myself → Cogito

– Descartes holds that there is one other special case: X = God → but this is not indubitable, it needs proof.

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Simplified Version of Trademark Argument

1. I have an idea of God.

2. My idea of God represents an infinitely perfect being.

3. I could not have such an idea, if there were no infinitely perfect being outside me.

Therefore

4. An infinitely perfect being, i.e. God, exists outside me.

5. Note that Descartes himself does not use “idea…represents” in the argument; instead he talks of the “objective reality of an idea”.

6. Note that Descartes puts his argument in terms of perfection/reality.

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• Pr1: Do we have an idea of God? Yes!

• Pr2: If someone’s so-called “idea of God” does not include ∞, too bad for them.

• Pr3?

• Watch Out!

– It is an idea of infinite perfection;

– It represents infinite perfection;

– This does not entail that the idea itself is infinitely perfect.

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Argument for Premise 3

5. Everything must have a cause.

Hence

6. The fact that my idea of God represents an infinitely perfect being must have a cause that is infinitely perfect.

7. I am not infinitely perfect.

Therefore

3. I could not have an idea representing an infinitely perfect being, if there were no infinitely perfect being outside me.

• Premise 7: – If there were infinite perfection in me, I couldn’t fail to notice it.

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• Step from 5 to 6:

– Descartes thinks that my idea couldn’t have the power to represent infinite perfection, unless it were caused by something infinitely perfect. Is that indubitable?

– Idea of infinity is crucial to the argument: “I could not have borrowed it from myself”, D says.

– But could I have put it together from the ideas of finite and not?

– Does 6 really follow from 5?

• Premise 5:

• The principle of causation: Everything must have a cause.

– is it indubitable? did he run it through the MoD?

– is it true?

– needs slight revision:

– Every contingent thing must have a cause.

• A contingent thing/being is a thing that exists but could have failed to exist; it does not exist necessarily, it is not a necessary being.

– did he run this through the MoD?

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Descartes’s Actual Procedure

• Degrees/levels of reality (being, perfection) ≈ levels of independence:

– Infinite Substance absolutely indep.

– Finite Substances indep. (relatively)

– Accidents/Attributes dep. on substances

– Modes dep. on subst. and their attributes

• Modes are ways in which a thing can be modified: a wrinkle in a carpet, a wave, a smile

• These are degrees of “formal reality”

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• Formal Reality ≈ “real” reality– Ideas have low formal reality: they are modes of thinking

• Objective Reality ≈ “represented” reality– The level of objective reality of an idea is given by the level of formal reality of what the

idea represents as being

• Compare with, e.g. Suarez (Item 2), though not exactly the same

• Cross-reality causal principle:– A more general and technical version of 6

– There must be at least as much formal reality in the efficient and total cause of an effect as there is formal + objective reality in the effect

– This makes the step from what an idea represents as being real to reality

– Compare analogy with craftsman, in Synopsis, p. 40a 1st

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• Along the way (p. 37-38a) he groups ideas into:

– clear and distinct ones:

• extension, shape, position, motion

• substance, duration, number

• = ideas of “primary properties”

– obscure and confused ones:

• light, colors, sounds, odors, sounds, heat and cold

• = ideas of “secondary properties”

• He argues that all these ideas could have come from himself.– idea of extension ?

• Only then does he gets to his idea of God; couldn’t have come from himself– Premises 1 and 2

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Readings for Thursday, Feb 9

• Descartes, Meditations

– Meditation Four

– Meditation Five

• By the way: Concourse Item 1

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• Along the way (p. 37-38a) he groups ideas into:

– clear and distinct ones:

• extension, shape, position, motion

• substance, duration, number

• = ideas of “primary properties”

– obscure and confused ones:

• light, colors, sounds, odors, sounds, heat and cold

• = ideas of “secondary properties”

• He argues that all these ideas could have come from himself.– idea of extension ?

• Only then does he gets to his idea of God; couldn’t have come from himself– Premises 1 and 2

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• Second Trademark Argument for God

– “From what source, then, do I derive my existence?”, pp. 52b 2nd to 53b 3rd

– Note: time, creation, conservation

• Wrap up of Med III:

• The idea of God does not come from the senses: it is innate, like the idea of my self.

– See p. 53b.

– Distinguish the idea of God, and the idea of existence, from the claim that God exists.

• Why is the argument called the “Trademark” argument?

– See p. 53b.

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Meditation IV: Concerning the True and the False

• Descartes: “God is not a deceiver”– Argument: God is infinitely perfect; hence, He has no imperfections. Therefore, He is not

a deceiver, because “it is manifest by the light of nature” that deception stems from a defect.

– See pp. 54a,b; reference to light of nature is code for “clear and distinct”.

• The Problem of Error: – If God is not a deceiver, doesn’t that make erroneous judgment impossible?

– That would be a reductio ad absurdum of Descartes’ argument.

– Compare with the problem of evil.

• Descartes offers a modified Free Will Defense to tackle this problem.

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• Descartes uses a modified Free Will Defense to tackle his problem.

• Descartes’ theory of judgment:

Judgment results from the cooperation of two faculties: the will and the understanding:

1. The understanding provides me with ideas to judge about; it is finite and imperfect:

• I lack ideas of many things

• Many of the ideas I do have are confused (= not clear and distinct).

2. The will is as close to infinite and unlimited as humans can get: the will is free! • Autonomy of persons; “created in God’s image” (55b 3rd – 56b)

• A judgment comes about when I decide freely to affirm or deny the ideas presented to me in my understanding.

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• Error results from my misuse of my free will.

– Erroneous judgment comes about when I decide to make judgments involving ideas that are not sufficiently clear to me (56b).

– I deceive myself!

– It is my fault, my imperfection, not God’s.

– Why did God allow me to deceive myself? The goodness of my freedom of will outweighs the badness brought about by my erroneous judgments.

• As long as I judge only what I understand clearly and distinctly, I cannot go wrong.

– 57a 3rd, 57b 2nd, 58a

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Two Worries

• Is judgment really free?

– Distinguish assertion from belief.

– Is belief free?

Is believing under our voluntary control?

• Can I believe that p just because I want to believe that p?

• Can I refrain from believing that p just because I don’t want to believe that p?

– Dubious.

• Isn’t Descartes already committed to the thesis that belief (judgment) is not always free?

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Readings for Tuesday, Feb 14

• Descartes, Meditations

– Meditation Four

– Meditation Five

– Meditation Six

– Meditation Six

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71

Meditation V: Concerning the Essence of Material Things, and…

• Ideas of material objects– Primary (quantitative) vs. Secondary (qualitative) ideas.

• Primary ideas

– Primary ideas of (properties of) material objects are clear and distinct;

– Ideas of extension, position, motion, number, duration and their sub-ideas.

• General laws of pure mathematics and pure mechanics

– involve only primary ideas;

– are pure because they are existence neutral.

– We find these laws by analyzing what is contained in our primary ideas:

• Definitions and their logical consequences.

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Descartes’ Ontological Argument for God’s Existence

• Compare with the version given in the 11th century by Anselm of Canterbury.

• The argument is supposed to be like a geometrical proof.

1. God is a being that has all perfections

2. Existence is a perfection

3. God exists

• Premise 1 is supposed to follow from the definition of God, just like “A triangle has three sides” follows from the definition of a triangle.

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• Premise 2: “Existence is a perfection”

– This does not imply: If x exists, then x is perfect!!

– Existence is a perfection.

– P is a perfection = P is a property “contributing” to perfection (greatness); that is: having P makes one more perfect (better) than one would be without P.

• Objection to Premise 2: “Existence is not a property” (P. Gassendi, Immanuel Kant)

– Descartes: Why not?

– Descartes: In any case, it’s a verbal issue, existence is presupposed by having properties/perfections; the argument can be rewritten.

– Descartes: Necessary existence is a property, and the argument can be strengthened to:

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Ontological Argument: Strengthened Version

1. God is a being that has all perfections2. Necessary existence is a perfection

3. God exists necessarily

• See “Meds arranged in Geometrical Fashion”, pp. 72-75, Proposition I and Demonstration.

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• Objection to Premise 1: “It has not been shown that the idea of God is consistent”, Leibniz, pp. 102-104.

– Anything follows from inconsistent definitions.

– Inconsistent definitions:

• definition of “the greatest number”;

• or define “the Bertrand-Barber” as the barber who shaves all those, but only those, people who do not shave themselves (Bertrand Russell).

• the Bertrand-Saint, who helps all those, but only those, who do not help themselves (?)

– Leibniz maintained that this objection can be answered, that the idea of God can be shown to be consistent:

If God is possible, then He is necessary.

God is possible.

Therefore, He is necessary.

M. C. Escher

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Meditation VI: Concerning the Existence of Material Things, and the Real Distinction between Mind and Body

• End of Med V:

– Omnipotent deceiver (evil demon) hypothesis is refuted.

– I have certain knowledge of “countless matters”: concerning God, the mind, and matter insofar as it is the object of pure mathematics and mechanics (clear and distinct, existence independent).

• Do material things exist?

– He knows they are possible (because they are the objects of pure mathematics).

– But are there actually any material things?

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• First argument for existence of material things: aborted– because it’s only a probable argument– See p. 61a, bottom to 62b 2nd para

• But note famous Chiliagon Argument (p. 61a):

– “Chiliagon”: a regular figure with 1000 sides.– We have the idea of chiliagon; but not from imagination or sense perception: it is an

intellectual idea. – Argues for distinction between imagination and sense perception, on the one hand,

and intellection, on the other hand.– See also argument at p. 59a: mathematical ideas are innate.

• Descartes takes a step back (p. 62b 3rd)

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• Reconsideration of sense perception (margin 62b-63b).

– He reminds himself of the sorts of things he used to believe concerning material things based on sense perception.

• Method of Doubt reapplied (63b).

• Announces that the results will be mixed (63b 3rd – 64a 1st):

– I shouldn’t doubt all that the senses have taught me; but I shouldn’t trust all of it either.

• Argument for Dualism (64a 2nd):

– I am really distinct from my body and can exist without it;

– That is, I am only a thing that thinks, I am an immaterial thing.

– [We’ll skip that for now]

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Argument for the existence of material objects

(Very rough reconstruction of pp. 64a 3rd to 65a 1st)

1. My perceptual ideas of material things must be caused by something.

2. I have a powerful natural inclination to assume that my perceptual ideas are, by and large, caused by material things outside me.

3. If this assumption were mistaken, God would be allowing me to be subject to systematic radical deception without giving me any means for detecting the deception.

4. That would be inconsistent with God’s not being a deceiver.

Therefore,

5. My perceptual ideas really are, by and large, caused by material things outside of me.

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• Shows only that my ideas of material things are by and large caused by material things.

– Sometimes we do suffer from hallucinations, etc.

– In many respects, material things may not be like I perceive them to be, because my ideas from sense perception are often confused (idea of the sun).

– But God has given me a faculty for correcting the mistakes I make due to confused ideas: the intellect → the new science.

• “Nature teaches me”

– Note line of reasoning: A strong natural inclination to believe/trust something which leads me into systematic, undetectable, radical illusion is impossible: because God is not a deceiver.

– When, in the following, Descartes says “nature teaches me” he refers to this line of reasoning.

Nature teaches me (65a-b)

• I have a body

• I am very closely joined/intermingled with my body

• Pain indicates damage to my body

• There are other bodies which can affect me beneficially or harmfully

• There are certain properties in bodies that somehow cause me to have qualitative ideas of colors, sounds, tastes, hot/cold, etc.

• Perceived qualitative differences of bodies correspond to real differences of some sort

Nature does not teach me (65b)

• There is a void

• Apparent sizes correspond to real sizes• There is something in bodies that

resembles my qualitative ideas of them

– instead, the fundamental quantitative properties of bodies cause me to have various qualitative ideas under normal circumstances

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• Mechanism or “the Mechanical Philosophy” – Fundamental physical properties of material things are extension (size and shape) and

motion;

– Fundamental laws of nature are mechanical laws describing bodies in motion through impact;

– Qualitative “properties” are not real;

• Qualitative ideas are responses of the mind to the impact of material things on human body → we project these ideas onto the world and wrongly take them for real qualities of things.

– Derives from ancient Atomism

• Democritus, Epicurus, Lucretius

– Not explicitly advocated in Meditations, but it’s waiting in the wings.

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Sense Perception and Mechanism

• Proper purpose of my sensations is to inform me about what is harmful or beneficial to my body (65b – 66a)

– I misuse my sensations when I treat them as reliable sources for immediate judgments about the nature of material objects

– Sense perception must be corrected by the intellect → the new science.

• Problem: Misleading sensations and appetites

– In response D treats “a man’s body as a kind of mechanism”

– Body and life are purely material, mechanical phenomena

– Mind and thinking are non-material

– Nonhuman animals are mere machines (no intellect)

Readings for Thursday, Feb 16

• Descartes:

– Meditation Six, pp. 64a 2nd – end – When you’re done, seriously re-read the one full paragraph on p. 64a– Really: it is D’s official argument for Dualism

• Concourse

– Item 3, David on Dualism.

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Descartes: L’Homme

• Descartes’s account of misleading sensations and appetites (pp. 66a 2nd – 68a 2nd)

– Phantom pain; harmful desires

– Human body is a machine, a mechanism: same input at any point along a nerve leads to same output in the brain

– The immaterial mind is “connected” to the body-machine in the brain (at pineal gland)

– Phantom pain is the mind’s response to a brain event that is normally caused by damage in foot

– Body-machine always follows the laws of nature, even when “it’s not working properly” (pp. 66a 3rd – b 1st): contra Aristotle

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Some quotes from Descartes’ The Passions of the Soul (329-31):

The heat and movement of the limbs proceed from the body, and the thoughts from the soul.

It is an error to believe that the soul gives movement and heat [i.e. life] to the body.

The error consists in supposing that since dead bodies are devoid of heat and movement, it is the absence of the soul which causes this cessation of movement and heat. Thus it has been believed, without justification, that our natural heat and all the movements of our bodies depend on the soul; whereas we ought to hold, on the contrary, that the soul takes its leave when we die only because this heat ceases and the organs which bring about bodily movement decay.

So as to avoid this error, let us note that death never occurs through the absence of the soul, but only because one of the principal parts of the body decays. And let us recognize that the difference between the body of a living and that of a dead man is just like the difference between, on the one hand, a watch or other automaton (that, is a self-moving machine) when it is wound up and contains in itself the corporeal principle of the movements for which it is designed…; and, on the other hand, the same watch or machine when it is broken and the principle of its movements ceases to be active.

• End of Meditations: Response to Dream Argument (68a 3rd – 68b)

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Readings for Tuesday, Feb 21

• Descartes, Meditation Six:

– Re-read the one full paragraph on p. 64a (“First”)– Re-read 2nd paragraph p. 67a (“first observation”)

• Concourse

– Item 3, David on Dualism.

• Descartes

– Discourse on the Method, Part 5, pp. 33 – 34.

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Body and Mind in Descartes

⎸• Body Life “So ul” Mind ⎸

• Aristotelian notion of soul combined aspects of life with aspects of mind/intellect.

• Descartes separates the two aspects:

– The living body is a machine: body & life are purely mechanical, material phenomena

– Mind is purely immaterial

– Soul = Mind

– Nonhuman animals (no intellect) are mere machines (cf. Discourse)

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Mind/Matter Theories

• Mind-Body Dualism, a.k.a Substance Dualism:

– Minds and bodies are two fundamentally different kinds of beings; minds are immaterial

beings, bodies are material beings.

• Materialism: Everything is matter

– (i) Mind is matter → Reductive Materialism

– (ii) There is no mind → Eliminative Materialism

• Idealism: Everything is mind

– (i) Matter is mind

– (ii) There is no matter

• Materialism and Idealism are versions of Monism.

• What about abstract “things” (numbers, Platonic forms, etc.): neither mind nor matter?

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Cartesian Dualism (CD):

(a) Minds are immaterial beings: no mind is identical with a body or with any material thing.

(b) Persons are minds: I am a mind.

• It follows immediately that: (c) Persons are immaterial beings.

– Note that (b) and (c) are specifically about persons

– (b) is argued for in Med II

– (a) is more general, not argued for in Med II

• (a) is part of Substance Dualism.

• CD combines Substance Dualism with Monism about Persons

– Persons are immaterial thinking things.

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• Descartes’ Substance Dualism (= Thesis (a))

– There are two fundamentally different kinds of substances (things, beings): minds and bodies, with two fundamentally different, defining attributes, thinking and extension.

– Minds are immaterial (non-extended) thinking things.

– Bodies are non-thinking material (extended) things.

– Minds and bodies have very little in common: only substance, number, and duration.

– Minds are not in space.

– Science and laws appropriate for one are very different from science and laws

appropriate for the other.

• Note: Substance Dualism, by itself, says nothing about persons.

• A substance: a genuine being, bearer of attributes, remains self-identical through change.

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Arguments for Substance Dualism

• Cartesian Argument 1:

I cannot doubt that I exists.I can doubt that this body exists.

I am not this body.

• Continuation:

The words “this body” can refer to any material thing. So:

I am not identical with any body.

By (b), we get:

My mind is not identical with any body,

Which can be generalized to:

(a) No mind is identical with a body.

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• Mocking argument:

Lois Lane cannot doubt that Superman is a superhero.

Lois Lane can doubt that Clark Kent is a superhero.

Superman is not Clark Kent.

• Against Cartesian Argument 1:

– the Mocking argument is unsound;

– Cartesian Argument 1 has the same structure as the unsound Mocking argument;

– hence: It is not trustworthy, invalid or unsound.

• Diagnosis: different “perspectives” on the same thing?

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• Argument 1

– Appears in Descartes’ earlier work Discourse on the Method.

– Descartes came to reject it

• See Meditations: Preface to the Reader.

• Cartesian Argument 2

– Is the one presented in Meditation VI, p. 64a 2nd.

– This is his main official argument for substance dualism.

– See Concourse Item 8.

– Does it, too, ultimately succumb to a version of the mocking-argument problem?

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Descartes’ Main Argument

1. If I can c&dly understand x to be F without understanding it to be G, and if I can c&dly understand y to be G without understanding it to be F, then x y.

2. I have a c&d idea of myself (my mind) as a thinking thing, but I don’t have a c&d idea of myself (my mind) as an extended thing.

3. I have a c&d idea of this body as an extended thing, but I don’t have a c&d idea of this body as a thinking thing.

Therefore

4. I (my mind) this body, and can exist without it. That is, my mind is not any extended thing at all and can exist without any extended thing.

5. Med VI, 64a, 2nd paragraph.

6. My reconstruction leaves out the sentence beginning “For this reason…” and the “merely”s in the second part. I think that none of that should be there.

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• Premise 1 is in first part of paragraph:

– If I can c&dly understand x without y, then God could separate them, i.e., He could make one exist without the other; but

– if it is so much as possible that x and y could be separated, then x y.

• Note: Distinguish non-identity, or distinctness, from being separated:– separability = distinctness; – distinctness does not imply being separated.

• Worry: Does Premise 1 raise the same problem as the old argument?

• The argument is supposed to establish Substance Dualism.

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Cartesian Dualism vs. Aristotle/Aquinas/Church

• Persons:– Descartes: Persons are immaterial minds.– Dogma: “Man consists of two essential parts—a material body and a spiritual soul.” (De

fide.)

• Mind/Soul:– Descartes: The mind/soul is a substance.– Dogma: “The rational soul is per se [by itself] the essential form of the body. (De fide.)”

– Ludwig Ott, Fundamentals of Catholic Dogma, 6th ed., Herder 1964.

• D’s view is compatible with continued existence of soul/mind and of persons after destruction of body (cf. Synopsis of Med II, p. 39ab)– Notorious difficulties for Aristotelians:

• Souls without bodies? and would it help?• Form without matter? Thinking without Imagination?

– But Descartes himself often flirts with “Union Dualism” (e.g. Med VI, p. 65ab)

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Readings for Thursday, Feb 23

• Anthology

– Nicolas Malebranche, The Search After Truth

– pp. 200 to 223.

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• Descartes: Mind without Matter

• Descartes: Matter without Mind!– Against animism

– Against soul-life connection

– Against soul as spring of motion (auto-mobile): Plato et al.

– Against Aristotle’s teleology (Med IV, pp. 66a 3rd – b 1st)

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Mind-Body Dualism and the Problem of Interaction

• Princess Elisabeth asked Descartes to explain

“how the mind, being only a thinking substance, can determine the body in producing voluntary actions”.

• Later she said:

“…it would be easier for me to admit matter and extension to the mind than it would be for me to concede the capacity to move a body and be moved by one to an immaterial thing.”

• Letters to Descartes, May and June 1643.

Descartes:

But I recognize only two ultimate classes of things: first, intellectual or thinking things, i.e. those which pertain to mind or thinking substance; and secondly, material things, i.e. those which pertain to extended substance or body. (Principles of Philosophy, 1.48)

…the difference between imagination and pure intellection…this power of imagining that is in me, insofar as it differs from the power of understanding, is not required for my own essence (Med VI, p. 61b, 62a) …the faculty of imagination, which I notice I use while dealing with material things…appears to be simply a certain application of the knowing faculty to a body intimately present to it. (Med VI, p. 61b)

…it is certain that I am really distinct from my body, and can exist without it. (Med. VI, p. 64a)

…nature also teaches that I am present to my body and not merely in the way a sailor is present in a ship, but that I am most tightly joined and, so to speak, commingled with it, so much so that I and the body constitute one single thing. For if this were not the case, then I, who am merely a thinking thing, would not sense pain when the body is injured… (Med VI, p. 65a)

…from the fact that some of these perceptions are pleasant while others are unpleasant, it is plainly certain that my body, or rather my whole self, insofar as I am composed of a body and a mind, can be affected by various…bodies in the vicinity. (Med VI, 65ab)

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…three primitive notions…as regards body, we have only the notion of extension…; as regards the soul on its own, we have only the notion of thought…; lastly, as regards the soul and the body together, we have only the notion of their union on which depends our notion of the soul’s power to move the body, and the body’s power to act on the soul and cause its sensations and passions. (Letter to Elisabeth, 21 May 1643)

…human beings are made up of body and soul, not by the mere presence or proximity of one to another, but by a true substantial union…If a human being is considered in itself, as a whole, it is an essential unity, because the union which joins a human body and soul to each other is not accidental to a human being, but essential, since a human being without it is not a human being. (Letter to Regius, 31 January 1642)

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• The Principle of Mind-Body Interaction:

– Human minds can interact with human bodies.– Physical events can cause mental events, and mental events can cause physical

events.

Note well: interaction.

Mind acting on Body:

– Intentional action!• raising my hand vs. my hand rising

– Stress and anxiety symptoms• butterflies, sweating

– Love symptoms • butterflies, sweating

Body acting on Mind:

– Sense Perception!• Knowledge of external world

– Pleasure and Pain

– Hunger, etc.

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The Anti-Dualism Argument

• Problem: If Dualism is true, How is mind-body interaction possible?

1. Human minds can interact with human bodies.

2. If Dualism were true, human minds could not interact with human bodies.

3. Dualism is false.

• Clearly valid.

• Second Premise:– How could something material push/be pushed by something immaterial?– Causal closure of the physical domain:

• Every physical event that has a cause has a physical cause.

– Conservation Laws.– Law of Inertia; F = ma; E = mc2

• Descartes (and Plato) advocate dualism and interaction:

– Is their position incoherent?

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Nicolas Malebranche (1638-1715)

• Advocate of Cartesianism– philosopher-priest– very influential at the time

• Contra Descartes– sensations vs. ideas (concepts)

– We have clear & distinct ideas of essence of matter but can’t prove its existence (need faith)

– We can prove existence of mind but don’t have clear & distinct idea of its essence

• Occasionalism– Dualism with a radical solution to the

problem of interaction

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Readings for Tuesday, Feb 28

• Anthology

– Nicolas Malebranche, The Search After Truth.

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• Sense Perception:– Material things causing immaterial ideas?

• The Search after Truth, Chap. 1 of Bk iii, Part ii.

– Malebranche denies body-to-mind causation! • Chap 3.

– “We see all things in God”! • Chaps. 6, 7.

• Intentional Action:– Malebranche also denies mind-to-body causation!

• Malebranche denies Interaction!

– He denies premise 1 of Anti-Dualism argument!• He denies that human minds can interact with human bodies.

– Your hand never rises because you want to raise it.

– The material objects you see, the changes in your eyes and brain, are not the causes of your visual experiences/ideas.

– The stone hitting your head is not the cause of your pain.

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Occasionalism:

• So called “natural causes” are not true causes; they are only the occasions at which God exercises His will.

• So-called “secondary causation” is unreal, an illusion, only “primary causation” (God’s causation) is real.– Search, Bk iv. part ii., Chapter 3, pp. 213-15; Elucidation 15.

• Is Occasionalism born from desparation?

– from the desire to save Dualism from the anti-dualist argument?

– that would be a motive but not an argument for Occasionalism

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Malebranche’s main argument for Occasionalism

1. A real cause requires a necessary connection between it and its effect.

2. There is a necessary connection only between the will of an omnipotent being and its effects.

Therefore:3. Only God is a real cause.

• Search, pp. 213-214.

• This argument is logically independent from Malebranche’s motivation for denying mind-body interaction to save Dualism.

• There is an additional argument involving knowledge and ignorance.

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Worries about Occasionalism

• There is no body-to-body causation either!

– That’s also excluded by Malebranche’s main argument.

• What about Freedom?– Mind-to-mind causation?

– Am I the cause of my own decisions?

– God’s freedom? Search, p. 215b 1st

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• Isn’t Occasionalism absurd? even insane?

– Well,…

– On the other hand: M’s theory contains a part explaining why his theory, if true, would seem absurd to us! Search, p. 205-6.

– Compare:

• When X happens, Y happens• Y happens because X happens• We tend to infer the second from the first: rash judgment.

– Correlation vs. Causation

• When X happens, Y happens: a common cause?

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• Minimal Anti-Dualism Argument

Some mind can act on bodies.

If Dualism is true, no mind can act on a body.

Dualism is false.

– This time, Malebranche will accept the first and reject the second premise.

– Human minds vs. God’s mind;

– Mind-body interaction vs. action of mind (God’s mind) on bodies

– Omnipotence and Logical Possibility

• Worry: And what about Freedom?– P. 215b 1st – P. 220

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“If it isn’t literally true that my wanting is causally responsible for my reaching, and my itching is causally responsible for my scratching, and my believing is causally responsible for my saying…, if none of that is literally true, then practically everything I believe about anything is false and it’s the end of the world.”

Jerry Fodor: ‘Making Mind Matter More’

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Readings for Thursday, March 1

• Anthology

– Thomas Hobbes, from the Leviathan.

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Continue with Part 2