Rationalist Epistemology Plato Descartes (427-347 B.C.E. )(1596-1650) Plato Descartes (427-347 B.C.E. )(1596-1650)

Rationalist EpistemologyRationalist Epistemology

Plato Plato Descartes Descartes (427-347 (427-347 B.C.E.B.C.E.)) (1596-1650)(1596-1650)

EpistemologyEpistemology

Is the philosophical study of Knowledge.Is the philosophical study of Knowledge. What is knowledge?What is knowledge? What is the difference between knowledge What is the difference between knowledge

and opinion? and opinion? What is the origin of knowledge?What is the origin of knowledge?

• Reason: Reason: RationalismRationalism• Experience: Experience: EmpiricismEmpiricism

How can we know something?How can we know something?

BelieveBelieveIn order for you to know X, you must In order for you to know X, you must believe X.believe X.

TruthTruthIn order for you to know X, X must be true.In order for you to know X, X must be true.

JustificationJustificationIn order for you to know X, you must be In order for you to know X, you must be able to give a justification for your belief.able to give a justification for your belief.

Gettier Problems. Gettier Problems.

Simile of the LineSimile of the Line____________________________________________________________________

Pure Reason The FormsPure Reason The Forms

____________________________________________________________________Understanding Scientific ConceptsUnderstanding Scientific Concepts

____________________________________________________________________Belief Sensible ObjectsBelief Sensible Objects

____________________________________________________________________Imagining ImagesImagining Images

__________________________________________________________________

OntologyOntology

ImagesImagesShadows and reflections of objects. Objects are Shadows and reflections of objects. Objects are more real than shadows because they last more real than shadows because they last longer and are not dependent on shadows.longer and are not dependent on shadows.

Sensible ObjectsSensible ObjectsThey are not absolutely real because they do They are not absolutely real because they do not last and they are dependent on other things, not last and they are dependent on other things, like the sun.like the sun. Conceptual LevelConceptual Level

We can know or understand sensible objects only by We can know or understand sensible objects only by grasping them at the conceptual level. You must grasping them at the conceptual level. You must know and apply the definition of a horse to know you know and apply the definition of a horse to know you see one. see one.

OntologyOntology

ConceptsConceptsCapture the unchanging relations. Things can Capture the unchanging relations. Things can fall in many different ways; but the concept of fall in many different ways; but the concept of gravity explains these events through one gravity explains these events through one unchanging law.unchanging law.

FormsFormsThe archetypes of everything existing in the The archetypes of everything existing in the visible universe. visible universe. Grasped by the intellect not the senses. Grasped by the intellect not the senses. Move from the definition to the formula.Move from the definition to the formula.

A prioriA priori Knowledge: Knowledge:Known independent of experience.Known independent of experience.

Two parallel lines cut by Two parallel lines cut by transversal. Prove A=H. transversal. Prove A=H.

A = D—Opposite angles A = D—Opposite angles are congruent.are congruent.

D = H—Corresponding D = H—Corresponding angles are congruent.angles are congruent.

A = H—substitution. A = H—substitution. What if we measure and What if we measure and

they are not equal?they are not equal?

Meno’s ParadoxMeno’s Paradox

How will you try to find out something How will you try to find out something (knowledge), Socrates, when you have no notion (knowledge), Socrates, when you have no notion at all what it is?at all what it is?

Innate IdeasInnate IdeasIdeas present in the soul of the individual from Ideas present in the soul of the individual from birth. There is nothing the soul has not already birth. There is nothing the soul has not already learned. Learning is really remembering what learned. Learning is really remembering what we already know. we already know. MenoMeno

He knew all along how to double the square, Socrates He knew all along how to double the square, Socrates helped him remember. helped him remember.

Descartes and the Descartes and the Copernican RevolutionCopernican Revolution

Geocentric ViewGeocentric ViewConsistent with religious view that Consistent with religious view that humans are the purpose of creation.humans are the purpose of creation.

Power of ReasonPower of ReasonThe church and the Non-scientist made The church and the Non-scientist made irrelevant.irrelevant. The Inquisition

Arrested Galileo in 1632 for discovering the Arrested Galileo in 1632 for discovering the moons of Jupiter. moons of Jupiter.

Copernicus (1473-1543)

DescartesDescartes

Reconciling Reason and FaithReconciling Reason and FaithScientific advances threaten the authority Scientific advances threaten the authority of the church. Descartes’ view reconciles of the church. Descartes’ view reconciles reason and faith.reason and faith. Uses reason and logicUses reason and logic To prove existence of God and Soul.To prove existence of God and Soul.

Descartes’ MethodDescartes’ Method

RationalismRationalismTrue knowledge comes from reason. True knowledge comes from reason. Thus it is Thus it is a prioria priori, known prior to , known prior to experience.experience. Innate IdeasInnate Ideas

Placed in our mind by God. (cp. to Plato’s Placed in our mind by God. (cp. to Plato’s forms)forms)

Mathematical ModelMathematical ModelFather of Trigonometry. Father of Trigonometry.

Descartes’ MethodDescartes’ Method

Methodic DoubtMethodic DoubtIf you are not sure, consider it false. Need If you are not sure, consider it false. Need to begin fresh with truthful propositions.to begin fresh with truthful propositions. Am I Dreaming?Am I Dreaming?

The senses cannot be trusted.The senses cannot be trusted. Evil Genius:Evil Genius: brain in a vat, or matrix. brain in a vat, or matrix.

““Clear and Distinct”Clear and Distinct” Standard of truth. Understand the Standard of truth. Understand the deduction.deduction. Standard Subjective?Standard Subjective?

Cogito, Ergo SumCogito, Ergo Sum

IndubitableIndubitableKnown clearly and distinctly, even if God is Known clearly and distinctly, even if God is an evil genius.an evil genius.

Immaterial SoulImmaterial SoulI know I exist as a I know I exist as a thinking thingthinking thing when I when I think. The soul is immaterial and can exist think. The soul is immaterial and can exist independent of the body. independent of the body.

I think, therefore I am.

Immaterial SoulImmaterial Soul

Cartesian Dualism Cartesian Dualism Mind and body separate realms that Mind and body separate realms that interact through pineal gland. interact through pineal gland. Independent but form whole.Independent but form whole.

Mind/Body Problem Mind/Body Problem How does something immaterial affect How does something immaterial affect our material body?our material body?

God God SolipsismSolipsism

All we can know is our own mind. God All we can know is our own mind. God needed for Descartes to get out of his needed for Descartes to get out of his mind.mind.

Ontological Argument Ontological Argument My idea of God is perfect; this idea My idea of God is perfect; this idea must come from something as perfect that must come from something as perfect that exists; God must exist.exists; God must exist.

GodGod Can’t Be Evil Genius Can’t Be Evil Genius

Would not be perfect.Would not be perfect. Senses and ReasonSenses and Reason

Can therefore be trusted because they come Can therefore be trusted because they come from God.from God.

External World Exists External World Exists He’s out of his mind.He’s out of his mind.

Our knowledge of self and God provide a Our knowledge of self and God provide a foundation for all knowledge. foundation for all knowledge.

Epistemology: the study of the nature, Epistemology: the study of the nature, source, limits, & justification of source, limits, & justification of

knowledgeknowledge RationalismRationalism: we truly : we truly knowknow only that of which only that of which

we are certain. Since sense experience we are certain. Since sense experience cannot guarantee certainty, reason alone cannot guarantee certainty, reason alone must be the means for getting knowledgemust be the means for getting knowledge Real knowledge about ourselves and the world Real knowledge about ourselves and the world

is is a prioria priori (prior to and independent of (prior to and independent of experience). “Knowledge” gained from sense experience). “Knowledge” gained from sense experience (experience (a posterioria posteriori) is guaranteed only by ) is guaranteed only by appeal to reasonappeal to reason

Rationalism: Sense Rationalism: Sense Experience Does Not Provide Experience Does Not Provide

KnowledgeKnowledge

DescartesDescartes: sense experiences are often : sense experiences are often wrong; I might be wrong about whether I wrong; I might be wrong about whether I have a body or if there is a world apart from have a body or if there is a world apart from my imagination (it may be a dream), and my imagination (it may be a dream), and even whether my reasoning abilities (e.g., even whether my reasoning abilities (e.g., 2+3=5) can be trusted (evil genie)2+3=5) can be trusted (evil genie)

Shankara: we correct our experiences of self and world (e.g., hallucinations, sense perceptions) by knowing the oneness of ultimate reality (Brahman)

(788-822)

ObjectionsObjections to Descartes’ to Descartes’ Method of DoubtMethod of Doubt

Even if some sense experiences are mistaken, Even if some sense experiences are mistaken, that is no reason to doubt (even hypothetically) that is no reason to doubt (even hypothetically) all of themall of them

Limiting knowledge only to what we know with Limiting knowledge only to what we know with certainty is too restrictive: we often certainty is too restrictive: we often knowknow things things a a posterioriposteriori (i.e., based on experience), not on (i.e., based on experience), not on indubitable foundationsindubitable foundations

If we doubt everything, we must also doubt whether we If we doubt everything, we must also doubt whether we are truly doubting—which requires us to assume the are truly doubting—which requires us to assume the existence of a public world of language usersexistence of a public world of language users

Descartes’ Escape from Descartes’ Escape from DoubtDoubt

I cannot doubt that I am doubting I cannot doubt that I am doubting (thinking). All other knowledge is based (thinking). All other knowledge is based on the undoubtable foundation that I exist: I on the undoubtable foundation that I exist: I think, therefore I exist (think, therefore I exist (cogito ergo sumcogito ergo sum))

I know I exist imperfectly only by first knowing I know I exist imperfectly only by first knowing perfect existence (God); and as a perfect perfect existence (God); and as a perfect being, God would not deceive me or allow me being, God would not deceive me or allow me to be deceived when I know something (e.g., to be deceived when I know something (e.g., wax) clearly and distinctly—that is, as an wax) clearly and distinctly—that is, as an intelligible (e.g., mathematical) objectintelligible (e.g., mathematical) object

Innate Ideas: Innate Ideas: knowledgeknowledge of ideas or principles is of ideas or principles is possible only if they are possible only if they are

inborninborn PlatoPlato: our knowledge of certain : our knowledge of certain

propositions is based on remembering propositions is based on remembering truths acquired before our birthtruths acquired before our birth

LeibnizLeibniz: our recognition of ideas and : our recognition of ideas and truths is based on innate dispositions of truths is based on innate dispositions of the mindthe mind

JainismJainism: past unethical behavior blinds : past unethical behavior blinds us to our innate knowledge of all thingsus to our innate knowledge of all things

EmpiricismEmpiricism

All knowledge of things in the All knowledge of things in the world is world is a posteriori a posteriori (that is, (that is, based ultimately on experience).based ultimately on experience).

Purely mental (i.e., Purely mental (i.e., a prioria priori) ) operations of reason do not operations of reason do not provide knowledge about the provide knowledge about the world.world.

John Locke (1632-1704):John Locke (1632-1704):Representational RealismRepresentational Realism

$ $ The mind at birth is a blank slate The mind at birth is a blank slate ((tabula rasatabula rasa): no ideas are innate): no ideas are innate

Knowledge is based on experience of simple Knowledge is based on experience of simple ideas (e.g., yellow) or complex ideas (lemon), ideas (e.g., yellow) or complex ideas (lemon), relations (father), abstractions (humanity)relations (father), abstractions (humanity)

We know about the world because our ideas of We know about the world because our ideas of “primary qualities” (e.g., solidity, shape) “primary qualities” (e.g., solidity, shape) represent things as they really are. Ideas of represent things as they really are. Ideas of secondary qualities (e.g., colors) represent secondary qualities (e.g., colors) represent things only as they appear to us. Qualities are things only as they appear to us. Qualities are supported by (unknown) substancessupported by (unknown) substances

George Berkeley (1685-George Berkeley (1685-1753)1753)

• Primary qualities depend on the Primary qualities depend on the mind just as much as secondary mind just as much as secondary qualitiesqualities

There is no way to show how primary There is no way to show how primary qualities represent qualities represent realreal external qualities external qualities or substancesor substances

What we perceive is the real world, but the only things What we perceive is the real world, but the only things we perceive are our ideas. So the real world consists we perceive are our ideas. So the real world consists only of ideas and the minds that perceive them only of ideas and the minds that perceive them (including God). That is, the world’s existence consists (including God). That is, the world’s existence consists in its being perceived (in its being perceived (esse est percipiesse est percipi) in regular ) in regular patternspatterns

David Hume: SkepticismDavid Hume: Skepticism

••All knowledge of the world is All knowledge of the world is a a posterioriposteriori—based on and limited to sense —based on and limited to sense impressions or copies of those impressions or copies of those impressions or creations of imagination impressions or creations of imagination (ideas)(ideas)

We have no impressions of self or causality (other We have no impressions of self or causality (other than temporal priority & continguity, but no necessary than temporal priority & continguity, but no necessary connection)—only habitconnection)—only habit

Notions of cause-effect and self are based on custom Notions of cause-effect and self are based on custom and natural inclination, not knowledgeand natural inclination, not knowledge

1711-1776

The Empiricists on The Empiricists on CauseCause

Locke: powers in material objects cause our ideas; Locke: powers in material objects cause our ideas; ideas of primary qualities represent external thingsideas of primary qualities represent external things

Berkeley: the concept of material objects outside our Berkeley: the concept of material objects outside our ideas is unintelligible; God causes our ideasideas is unintelligible; God causes our ideas

Hume: because the concept of cause is a relation of Hume: because the concept of cause is a relation of our ideas, a cause of our ideas is unintelligibleour ideas, a cause of our ideas is unintelligible

God

External material bodies

Ideas in our mind

“cause” is merely a habit of mind

Immanuel Kant (1724-Immanuel Kant (1724-1804)1804)

Rationalism is wrong: we are not born with Rationalism is wrong: we are not born with innate ideas (e.g., equality, God, shortest innate ideas (e.g., equality, God, shortest distance is a straight line, future events will distance is a straight line, future events will always have causes); we know things about the always have causes); we know things about the world only through perceptionsworld only through perceptions

Empiricism is wrong: sense data alone do not Empiricism is wrong: sense data alone do not give us give us knowledgeknowledge of the world. We can of the world. We can knowknow only if our minds are not blank slates or passive only if our minds are not blank slates or passive receptacles of neutral sense datareceptacles of neutral sense data

Kant’s Epistemology: Kant’s Epistemology: Transcendental IdealismTranscendental Idealism

We know about things in the world not as they We know about things in the world not as they are in themselves (as noumena)are in themselves (as noumena) but only but only insofar insofar as they appear to usas they appear to us (as phenomena), universally (as phenomena), universally structured by the mind’s categories (e.g., space, structured by the mind’s categories (e.g., space, time, cause)time, cause) Objections: (1) If we are limited to Objections: (1) If we are limited to phenomena,phenomena,

we cannot know whether the world is really as we cannot know whether the world is really as it appears; (2)it appears; (2) categories differ culturally and categories differ culturally and linguistically (Sapirlinguistically (Sapir–Whorf hypothesis)–Whorf hypothesis)

Principles of Scientific Principles of Scientific KnowledgeKnowledge

Using Using inductiveinductive reasoning and preferring the simplest reasoning and preferring the simplest generalizations, we can derive probable laws from observations generalizations, we can derive probable laws from observations and repeated confirmationsand repeated confirmations The problem of induction: past experiences can be used to The problem of induction: past experiences can be used to

predict the probability of future ones only if the future is like predict the probability of future ones only if the future is like the past—and that is unknownthe past—and that is unknown

Instead of relying on induction, theories (e.g., evolution) use the Instead of relying on induction, theories (e.g., evolution) use the hypotheticalhypothetical method to formulate experiments that are method to formulate experiments that are falsifiablefalsifiable

Francis Bacon J. S. Mill

Karl Popper

Scientific Paradigms, Revolutions, Scientific Paradigms, Revolutions, and Pseudoscienceand Pseudoscience

• • Scientific knowledge is organized according Scientific knowledge is organized according to to paradigmsparadigms (sets of theories and practices (sets of theories and practices adopted by scientists to explain observations)adopted by scientists to explain observations)

When “anomalies” occur with regularity, one When “anomalies” occur with regularity, one paradigm replaces another in a scientific paradigm replaces another in a scientific revolution. This new way of organizing research revolution. This new way of organizing research transforms the discipline, changes the objects transforms the discipline, changes the objects studied, and generates new discoveries: studied, and generates new discoveries: progress is thus not gradual or incrementalprogress is thus not gradual or incremental Pseudoscience is not falsifiable and does not Pseudoscience is not falsifiable and does not

suggest new experiments to be testedsuggest new experiments to be tested

Thomas Kuhn

Definition of KnowledgeDefinition of Knowledge

To say that you To say that you knowknow X means: X means: you you believebelieve X to be true X to be true there is some there is some reason or justification reason or justification

(warrant) for thinking that X is true(warrant) for thinking that X is true X is, in fact, trueX is, in fact, true

• Gettier problem: you could have a Gettier problem: you could have a warranted true belief and still not warranted true belief and still not knowknow

E. Gettier (1927- )

Theories of TruthTheories of Truth CorrespondenceCorrespondence: truth is an objective relation between : truth is an objective relation between

beliefs and extramental reality (i.e., facts)beliefs and extramental reality (i.e., facts) ObjectionObjection: we cannot access extramental reality: we cannot access extramental reality

CoherenceCoherence: a proposition or belief is true if it is : a proposition or belief is true if it is coherent with other accepted beliefscoherent with other accepted beliefs ObjectionObjection: coherent systems of intersubjectively : coherent systems of intersubjectively

accepted beliefs could still be falseaccepted beliefs could still be false PragmaticPragmatic: if acting on a belief satisfies our : if acting on a belief satisfies our

expectations—that is, if it works—it is trueexpectations—that is, if it works—it is true ObjectionsObjections: (a) justified beliefs are not necessarily : (a) justified beliefs are not necessarily

true; (b) this make all truths relative; (c) beliefs are true; (b) this make all truths relative; (c) beliefs are not true because they “work”; they work because not true because they “work”; they work because they are true they are true

Scientific TruthScientific Truth Instrumentalism: theoretical entities are simply Instrumentalism: theoretical entities are simply

practical means for making predictions; they do practical means for making predictions; they do not describe extra-theoretical realitiesnot describe extra-theoretical realities Parallels Pragmatic theory of truthParallels Pragmatic theory of truth

Realism: claims about theoretical entities are Realism: claims about theoretical entities are true only if they describe the real worldtrue only if they describe the real world Parallels Correspondence theory of truthParallels Correspondence theory of truth

Conceptual Relativism: claims about reality are Conceptual Relativism: claims about reality are intelligible only in terms of the theoretical intelligible only in terms of the theoretical frameworks in which observations are madeframeworks in which observations are made Parallels Coherence theory of truthParallels Coherence theory of truth

How Claims of Knowledge Are How Claims of Knowledge Are JustifiedJustified

Foundationalism: knowledge claims are based Foundationalism: knowledge claims are based on indubitable foundationson indubitable foundations I can doubt whether there is a world, whether I can doubt whether there is a world, whether

my reasoning can be trusted, and even if I my reasoning can be trusted, and even if I have a body, but I cannot doubt that I am have a body, but I cannot doubt that I am doubting (thinking). Knowledge of God and doubting (thinking). Knowledge of God and the world is based on intuitive knowledge of the world is based on intuitive knowledge of my own existencemy own existence

Only sense experience can provide Only sense experience can provide real knowledge of the world real knowledge of the world

How Claims of Knowledge Are How Claims of Knowledge Are JustifiedJustified

Coherent: knowledge claims are justified only if Coherent: knowledge claims are justified only if they are consistent with other beliefs (including they are consistent with other beliefs (including empirical beliefs) that support and complete the empirical beliefs) that support and complete the whole set of beliefs whole set of beliefs

Objections:Objections: Against foundationalism: why think that any Against foundationalism: why think that any

belief (intuitive or empirical) is justified?belief (intuitive or empirical) is justified? Against coherentism: why think that a belief is Against coherentism: why think that a belief is

true just because it coheres with others?true just because it coheres with others?

Knowledge and Justified True BeliefKnowledge and Justified True Belief Traditionally, “Traditionally, “xx knows knows pp” means:” means:

xx believes that believes that p; pp; p is true; is true; xx is justified in is justified in believing that believing that pp

Gettier problem: all three conditions Gettier problem: all three conditions could hold and still not have knowledgecould hold and still not have knowledge Externalism (Plantinga): I might be Externalism (Plantinga): I might be

warrantedwarranted in my belief (if my procedure for in my belief (if my procedure for getting the information is reliable) without getting the information is reliable) without being being justifiedjustified (i.e., I might not know how (i.e., I might not know how my belief is based on that procedure)my belief is based on that procedure)

Hermeneutics:Hermeneutics:The Study of InterpretationThe Study of Interpretation

• Schleiermacher: a true interpretation reveals Schleiermacher: a true interpretation reveals the historical author’s real intentionsthe historical author’s real intentions

Early Wittgenstein: propositions that really picture the Early Wittgenstein: propositions that really picture the structure of the world are truestructure of the world are true

Later Wittgenstein: meaning varies with use in lifeLater Wittgenstein: meaning varies with use in life

• • Gadamer: our interpretations combine our Gadamer: our interpretations combine our “prejudices” and authorial intentions“prejudices” and authorial intentions

To determine truth in texts and actions, we have to interpret them (literally, symbolically)

Epistemology: the study of the nature, Epistemology: the study of the nature, source, limits, & justification of source, limits, & justification of

knowledgeknowledgeSkepticismSkepticism: doubt that knowledge is possible: doubt that knowledge is possible

• Taoism: the differentiation of things is relative; all things are really one

Chuang Tzu (369-286 BCE)

Sextus Empiricus (2nd

Century)

• Pyrrhonism: we should refuse to make dogmatic claims to know because all knowledge is relative

Cartesian DoubtCartesian Doubt

Sense experiences are often wrongSense experiences are often wrong I might be wrong about whether I have I might be wrong about whether I have

a body or if there is a world apart from a body or if there is a world apart from my imagination (it may be a dream)my imagination (it may be a dream)

I might be wrong even about whether I might be wrong even about whether my reasoning abilities (e.g., 2+3=5) can my reasoning abilities (e.g., 2+3=5) can be trusted (evil genius); so I should be trusted (evil genius); so I should suspend judgmentsuspend judgment

René Descartes (1596-1650)

ObjectionsObjections to Descartes’ to Descartes’ Method of DoubtMethod of Doubt

To think some experiences are wrong is to To think some experiences are wrong is to assume that some are rightassume that some are right

To doubt everything, we must doubt whether To doubt everything, we must doubt whether we are truly doubting, and that requires us to we are truly doubting, and that requires us to assume a public world of language usersassume a public world of language users

Limiting knowledge only to what we know Limiting knowledge only to what we know with certainty is too restrictive: we often with certainty is too restrictive: we often knowknow things not based on indubitable foundationsthings not based on indubitable foundations

Hume: Skepticism about the Hume: Skepticism about the External WorldExternal World

The continued existence of things apart from our The continued existence of things apart from our experience cannot be known, for we cannot compare experience cannot be known, for we cannot compare our experience (or self) with anything outside it as its our experience (or self) with anything outside it as its supposed causesupposed cause

Problem of induction: we cannot say that something is Problem of induction: we cannot say that something is probable without assuming that the future will probable without assuming that the future will resemble the pastresemble the past Induction itself is unjustifiable (Strawson)Induction itself is unjustifiable (Strawson)

Rationalism: Knowledge Is Rationalism: Knowledge Is Acquired through Reason, not the Acquired through Reason, not the

SensesSenses We We knowknow only that of which we are only that of which we are

certain. Sense experience cannot certain. Sense experience cannot guarantee certainty, so all that we guarantee certainty, so all that we knowknow comes from reason alone and is comes from reason alone and is a prioria priori (i.e., prior to experience)(i.e., prior to experience)

Our (innate) knowledge of certain Our (innate) knowledge of certain propositions is based on remembering propositions is based on remembering truths acquired before birthtruths acquired before birth Plato

(427-347 BCE)

EmpiricismEmpiricism: Knowledge about the : Knowledge about the World Is World Is A PosterioriA Posteriori (Based on (Based on

Experience Alone)Experience Alone) At birth the mind is a blank slate (At birth the mind is a blank slate (tabula rasatabula rasa), ),

containing no innate ideas. Even if some ideas containing no innate ideas. Even if some ideas were known universally, that does not prove were known universally, that does not prove they are innatethey are innate

Knowledge comes from sensation or reflectionKnowledge comes from sensation or reflection Ideas of “primary qualities” (e.g., solidity, Ideas of “primary qualities” (e.g., solidity,

shape) represent things as they really are; shape) represent things as they really are; ideas of secondary qualities (e.g., colors) ideas of secondary qualities (e.g., colors) represent things only as they appear to usrepresent things only as they appear to us

Naïve RealismNaïve Realism: We Do Not : We Do Not Perceive Ideas; We Perceive Their Perceive Ideas; We Perceive Their

ObjectsObjects

Perceptions are always “intentional,” that is, Perceptions are always “intentional,” that is, aboutabout something; and when our perceptions something; and when our perceptions are are causedcaused by the things they are about, we by the things they are about, we can be said to can be said to knowknow those things those things

Perceptions are not purely passive; they are Perceptions are not purely passive; they are affected by one’s background knowledge affected by one’s background knowledge and beliefsand beliefs

John Searle

Analytic and Synthetic Analytic and Synthetic JudgmentsJudgments

Hume: propositions are either relations of ideas Hume: propositions are either relations of ideas (analytic, (analytic, a prioria priori) or matters of fact (synthetic, ) or matters of fact (synthetic, a a posterioriposteriori))

Kant: propositions in mathematics (7+5=12) and Kant: propositions in mathematics (7+5=12) and metaphysics (“all events have causes”) are synthetic metaphysics (“all events have causes”) are synthetic a prioria priori judgments judgments

Quine: meanings of terms in even Quine: meanings of terms in even a prioria priori analytic analytic propositions depend on experiencepropositions depend on experience

David Hume Immanuel Kant

A “free” act is simply one that is caused (i.e., A “free” act is simply one that is caused (i.e., preceded) by our choice or act of will. We are preceded) by our choice or act of will. We are free when we can do what we want.free when we can do what we want.

Objection: aren’t choices caused by “external” forces (e.g., genetics, culture, upbringing)?

Compatibilism:Compatibilism:freedom is compatible with freedom is compatible with

determinismdeterminism

Hume

actchoice/will/personality

external threats/constraints

cause

cause

(free)

(not free)

The Justification for The Justification for CompatibilismCompatibilism

Free actions are not only compatible Free actions are not only compatible with determinism; they assume with determinism; they assume determinism. That is, we assume that an determinism. That is, we assume that an action is “free” only if it is based on (i.e., action is “free” only if it is based on (i.e., causedcaused by) a person’s character and by) a person’s character and desiresdesires

If an action is not linked to a person’s If an action is not linked to a person’s decision to do it, it is either coerced or decision to do it, it is either coerced or random. In either case, it is not done freelyrandom. In either case, it is not done freely

Implications of CompatibilismImplications of Compatibilism

1.1. Even though all our actions are caused, Even though all our actions are caused, we still can have we still can have reasonsreasons for our actions. for our actions. We might not choose those reasons or We might not choose those reasons or goals freely, but they are goals freely, but they are ourour goals goals

2.2. The achievement of goals requires that The achievement of goals requires that we act. Deliberation still makes sense we act. Deliberation still makes sense because it is essential in bringing about because it is essential in bringing about an outcomean outcome

More Implications of More Implications of CompatibilismCompatibilism

3.3. People are responsible only for those acts People are responsible only for those acts that are intentional (i.e., acts that are not that are intentional (i.e., acts that are not mistaken, accidental, coerced, or done out mistaken, accidental, coerced, or done out of ignorance or as a result of insanity). of ignorance or as a result of insanity). However, intentional acts are still causedHowever, intentional acts are still caused

4.4. Even if people Even if people areare not responsible for their not responsible for their actions, they can still be actions, they can still be heldheld responsible responsible

What Does It Mean to Know What Does It Mean to Know Something?Something?

Externalism: I Externalism: I knowknow something if my something if my belief correctly matches the “external” belief correctly matches the “external” world (even if I don’t know how it does)world (even if I don’t know how it does) A belief is A belief is warrantedwarranted if it is based on a if it is based on a

procedure that yields true beliefs; and it procedure that yields true beliefs; and it is is justifiedjustified if it is based on reliable if it is based on reliable information produced by such a information produced by such a procedure (reliabilism)procedure (reliabilism)

Production of such information is due to Production of such information is due to facts about the world (naturalism)facts about the world (naturalism)

Plantinga

An Objection to An Objection to ExternalismExternalism

Even if the information I have is Even if the information I have is reliable and correct, I cannot be reliable and correct, I cannot be

said to said to knowknow it unless I (internally) it unless I (internally) know know thatthat it is reliable and correct it is reliable and correct

Keith Lehrer

Good thinkers learn to spot what is Good thinkers learn to spot what is reliable and correct by developing reliable and correct by developing virtues of mind. For example, they strive to:virtues of mind. For example, they strive to: accept reliable testimony, avoid hasty accept reliable testimony, avoid hasty

generalizations, consider counter-generalizations, consider counter-arguments, be open-minded, persevere in arguments, be open-minded, persevere in inquiry, integrate beliefs, explain complex inquiry, integrate beliefs, explain complex sets of data, recognize how knowledge is sets of data, recognize how knowledge is socialsocial

this is not a procedure; it is a way of lifethis is not a procedure; it is a way of life

Linda Zagzebski

Virtue EpistemologyVirtue Epistemology

How Can We Know Anything How Can We Know Anything about the World Around Us?about the World Around Us?

• Idealism: we can know about the world Idealism: we can know about the world because it is comprised of our ideasbecause it is comprised of our ideas

• Phenomenalism: physical objects are Phenomenalism: physical objects are knowable, but only as bundles of sense knowable, but only as bundles of sense datadata

• Naïve Realism: we do not perceive Naïve Realism: we do not perceive ideas or mental representationsideas or mental representations

Idealism:Idealism:George Berkeley (1685-George Berkeley (1685-

1753)1753) What we perceive is the real world, but What we perceive is the real world, but

the only things we perceive are our ideas. the only things we perceive are our ideas. So the world consists only of ideas and So the world consists only of ideas and the minds that perceive them (including the minds that perceive them (including God). That is, the world’s existence God). That is, the world’s existence consists in its being perceived (consists in its being perceived (esse est esse est percipipercipi)) Objection: this seems to deny that Objection: this seems to deny that

physical bodies existphysical bodies exist

Phenomenalism:Phenomenalism:John Stuart Mill (1806-73)John Stuart Mill (1806-73)

Things are knowable because they are Things are knowable because they are simply phenomena (things that appear simply phenomena (things that appear to us under certain conditions)to us under certain conditions)

We know things in the world because We know things in the world because they are “permanent possibilities of they are “permanent possibilities of sensation”sensation” Objection: things don’t exist because Objection: things don’t exist because

they are experienceable; they are they are experienceable; they are experienceable because they existexperienceable because they exist

Transcendental Idealism: Transcendental Idealism: Immanuel Kant (1724-1804)Immanuel Kant (1724-1804)

We know about things not as they are in We know about things not as they are in themselves but only themselves but only as they appear to usas they appear to us (as phenomena), structured by the mind’s (as phenomena), structured by the mind’s categories (e.g., space, time, cause)categories (e.g., space, time, cause) Objections: (1) If we are limited to Objections: (1) If we are limited to

phenomena,phenomena, we can’t know what the world we can’t know what the world is really like; (2)is really like; (2) categories differ culturally; categories differ culturally; (3) this does not explain why we have only (3) this does not explain why we have only these categoriesthese categories

Naïve RealismNaïve Realism: We Do Not : We Do Not Perceive Ideas; We Perceive Their Perceive Ideas; We Perceive Their

ObjectsObjects

Perceptions are always “intentional,” that is, Perceptions are always “intentional,” that is, aboutabout something; and when our perceptions something; and when our perceptions are are causedcaused by the things they are about, we by the things they are about, we can be said to can be said to knowknow those things those things

Perceptions are not purely passive; they are Perceptions are not purely passive; they are affected by one’s background knowledge affected by one’s background knowledge and beliefsand beliefs

John Searle

Social Constructionism: Knowledge Social Constructionism: Knowledge is a Creation Based on Social is a Creation Based on Social

InterestsInterestsScienceScience is not the objective accumulation of is not the objective accumulation of

facts, because “facts” are answers to facts, because “facts” are answers to questions framed in incommensurable questions framed in incommensurable theoretical frameworks (theoretical frameworks (paradigmsparadigms))

Epistemological RelativismEpistemological Relativism: : knowledgeknowledge varies in varies in conceptual schemes with different criteria for conceptual schemes with different criteria for justification, truth, & rationalityjustification, truth, & rationality

• Communal interests determine how to Communal interests determine how to evaluate different paradigmsevaluate different paradigms

Thomas Kuhn

The Gendered Character of The Gendered Character of KnowledgeKnowledge

Feminine characterizations of knowledge aim at Feminine characterizations of knowledge aim at explanation and understanding instead of an explanation and understanding instead of an adversarial determination of “facts” removed from their adversarial determination of “facts” removed from their contextscontexts

This does not imply that women are “naturally” This does not imply that women are “naturally” different from men (e.g., more sensitive or less different from men (e.g., more sensitive or less objective); such essentialism ignores how even objective); such essentialism ignores how even gender is a social constructgender is a social construct

What is What is knowableknowable is determined by relations of power is determined by relations of power in a disciplinein a discipline

Lorraine Code

Michel Foucault

The Gendered Character of The Gendered Character of KnowledgeKnowledge

Feminine characterizations of Feminine characterizations of knowledge aim at explanation and knowledge aim at explanation and understanding instead of an understanding instead of an adversarial determination of “facts” adversarial determination of “facts” removed from their contextsremoved from their contexts

Lorraine Code

• Feminism questions philosophical assumptions about mind and thinking by showing how emotions and feelings are sources of truth and guides for reasoning

Morwenna Griffiths

““Feminism, Feelings, and Feminism, Feelings, and Philosophy”Philosophy”

Emotions (e.g., fear, love, pride) are not simply Emotions (e.g., fear, love, pride) are not simply intellectual judgments that result in action, and intellectual judgments that result in action, and feelings (e.g., sexuality, hunger) are not simply feelings (e.g., sexuality, hunger) are not simply bodily sensationsbodily sensations

This insight challenges the philosophic inclination This insight challenges the philosophic inclination to portray emotions and feelings in terms of a to portray emotions and feelings in terms of a dualism of mind and bodydualism of mind and body

Emotions and feelings cannot easily be linked to Emotions and feelings cannot easily be linked to mind or body exclusively, and neither mind nor mind or body exclusively, and neither mind nor body dominatesbody dominates

The Feminist AlternativeThe Feminist Alternative

Feelings become meaningful as Feelings become meaningful as human emotions over time and in social human emotions over time and in social (e.g., linguistic) contexts when they are (e.g., linguistic) contexts when they are understood and acted uponunderstood and acted upon

This means that feelings affect and are This means that feelings affect and are affected by our understanding and our affected by our understanding and our communal interactions—and thus guide communal interactions—and thus guide our philosophical enquiriesour philosophical enquiries

Constructivist Confusions: Alan Constructivist Confusions: Alan SokalSokal

To say that “physical reality is a social and linguistic To say that “physical reality is a social and linguistic construct” is to confuse:construct” is to confuse: objects in the world with what we say about themobjects in the world with what we say about them how we get knowledge with its reliabilityhow we get knowledge with its reliability knowledge about the world with social, political, or knowledge about the world with social, political, or

ethical uses of such knowledgeethical uses of such knowledge Reply: objective/subjective distinctions are Reply: objective/subjective distinctions are

naïve, unjustified, and even dangerousnaïve, unjustified, and even dangerous

The Alternative to Foundationalist The Alternative to Foundationalist EpistemologyEpistemology

Knowledge is not based on insights into Knowledge is not based on insights into indubitable principles about things in the indubitable principles about things in the world or sense experiences of the worldworld or sense experiences of the world

Rather, our knowledge is an interlocking Rather, our knowledge is an interlocking web of beliefs in terms of which we agree to web of beliefs in terms of which we agree to speak in ways that we acknowledge are speak in ways that we acknowledge are open to later revisionopen to later revision