Descartes(
Wolff,(pages(49265(
Sophie’s(World(Chapter(18(
Background(
•
•
•
•
159621650(
French(
Devout(Catholic((educated(by(Jesuits)(
IniJally(interested(in(mathemaJcs(and(physics(
–  Father(of(analyJc(geometry,(contributed(to(
advancements(in(algebra;(Cartesian(plane(
•  Father(of(modern(philosophy(
–  Medita'ons+on+First+Philosophy,(1641(
•  Rejected(convenJonal(wisdom,(established(
doctrine,(and(the(authority(of(the(ancients(
Discourse(on(Method(
•  1637:(“Discourse(on(the(Method(of(Rightly(ConducJng(
the(Reason(and(Seeking(for(Truth(in(the(Sciences”(
–  Four(Parts(
•  “The(first(of(these(was(to(accept(nothing(as(true(which(
I(did(not(clearly(recognize(to(be(so…”(
•  “The(second(was(to(divide(up(each(of(the(difficulJes(
which(I(examined(into(as(many(parts(as(possible…”(
•  “The(third(was(to(carry(on(my(reflecJons(in(due(
order…”(
•  “The(last(was…make(enumeraJons(so(complete(and(
review(so(general(that(I(should(be(certain(of(having(
omi_ed(nothing.”(
Discourse(on(Method(
•  Method(of(Inquiry(
–  Method(for(finding(things(out(and(being(sure(you(
have(them(right(
–  Not(to(prove(what(you(already(know(
–  Similar(to(Socrates?(
•  Method(of(Doubt(
–  Do(not(accept(something(as(true(unless(you(have(
absolute(certainty(
–  Cannot(completely(trust(your(senses(
–  Similar(to(Plato?(
Cogito,(ergo(sum.(
•  “I(think,(therefore(I(am.”(
–  Did(not(doubt(his(own(existence(
•  Idea(of(perfect(enJty(comes(from(God(
–  Self2evident(to(Descartes(that(God(existed,(idea(of(
God(is(innate(
•  Two(realiJes((dualism)(
–  Thought(and(Extension((ma_er)(
–  Mind(is(purely(conscious(
–  Ma_er(takes(up(space(and(can(be(divided((but(has(no(
conscious)(
–  Thought(is(independent(of(ma_er(in(humans(
Mind(and(Body(
•  Man(thinks,(but(also(takes(up(space((thought(
and(ma_er)(
•  Bodily(funcJons(do(not(rely(on(mind(
•  Mind(acts(independently(from(bodily(funcJon(
•  Mind(and(body(do(have(constant(interacJon(
–  Thought(can(be(affected(by(feelings(related(to(
bodily(needs(
–  Ability(to(behave(raJonally(
Epistemological(Turn(
•  Pre2SocraJcs(!(Descartes(
–  QuesJons(of(being(came(before(quesJons(of(
knowing(
–  The(philosophy(of(Descartes(flips(this(order(
•  Differing(with(Aristotle(on(physics(
•  Epistemological(SkepJcism(
Philosophical(Responses(to(Descartes(
•  The(“problem(of(certainty”(
•  RaJonalists(
–  Sought(to(discover(ways(of(establishing(principles(of(
science(and(metaphysics(with(mathemaJcal(certainty(
–  Sought(proofs(for(the(existence(of(God(
–  Downgraded(senses(as(a(source(of(knowledge(
•  Empiricists(
–  Argued(that(nothing(could(meet(the(demand(of(the(
raJonalists(
–  Challenged(raJonalists(reliance(on(reason(as(sole(
source(of(knowledge(
RaJonalism(and(Empiricism(
Wolff,(pages(61282(
Problem(of(Certainty(
•  Cogito(Argument(
•  Solipsism(
•  Two(types(of(beliefs(
–  Based(on(the(senses(
–  Based(on(reasoning(with(general(concepts(
•  Problem(of(certainty(
–  Clear(and(disJnct(
a(priori(vs.(a(posteriori(
•  A(priori2knowledge(reached(through(deducJon(
–  conclusions(are(based(on(intuited(premises(and(valid(
arguments(
–  ArithmeJc,(geometry(
–  RaJonalism(
•  A(posteriori2knowledge(dependent(on(experience(
–  Sensory(percepJon/experience(necessary(to(trigger(
thinking(and(understanding(of(the(world(
–  Physics,(chemistry,(biology(
–  Empiricism(
Leibniz(and(RaJonalism(
•  The+Monadology2two(types(of(truths+
–  Truths(that(can(be(known(by(applicaJon(of(a(
fundamental(principle(of(logic(
•  Law(of(ContradicJon(and(Law(of(the(Excluded(Middle(
•  NegaJon(
–  Truths(of(fact—knowledge(
Locke(and(Hume2empiricists(
•  John(Locke2tabula(rasa(
•  David(Hume2A+Trea'se+on+Human+Nature(
–  Impressions/percepJons(vs.(ideas(
–  Simple(and(complex(
–  Copy(theory(of(ideas(
–  Ability(of(the(mind(to(separate(“units”(of(
sensaJon(
Immanuel(Kant(
•  claimed(that(knowledge(was(impossible(without(
accepJng(truths(from(both(raJonalist(and(
empiricist(schools(of(thought(
•  Unity(of(Consciousness(
•  “Categories”(
•  “There(can(be(no(doubt(that(all(our(knowledge(
begins(with(experience.(But(though(all(our(
knowledge(begins(with(experience,(it(does(not(
follow(that(it(all(arises(out(of(experience.”((
•  “Concepts(without(percepts(are(empty;(percepts(
without(concepts(are(blind.”(
Epistemology(Review(
Epistemology(
•  The(study(of(knowledge(
•  What(does(it(mean(to(know(something?(
•  What(are(the(criteria(of(certainty(in(
knowledge?(
•  What(are(the(sources(of(our(knowledge?(
•  What(limits,(if(any,(are(there(on(what(the(
human(mind(can(know?(
•  Can(we(know(that(we(know?(How?(
Descartes(
•  Discourse(on(Method(
–  Method(of(inquiry(and(Method(of(doubt(
–  Leads(to(“epistemological(turn”(
•  “Clear(and(disJnct”(
•  Epistemological(skepJcism(
•  Cogito(argument/solipsism(
RaJonalism(vs.(Empiricism(
•  A(priori(knowledge(vs.(A(posteriori(knowledge(
•  Leibniz—raJonalist(
–  Role(of(formal(logic(
–  Law(of(contradicJon(
–  Law(of(sufficient(reason(
•  Tabula(Rasa—John(Locke(
•  David(Hume—empiricist(
–  “Every(simple(idea(is(a(copy(of(a(precedent(simple(impression”(
•  Immanuel(Kant(
–  Goes(back(to(cogito(argument(
–  Uses(“categories”(to(explain(“unity(of(consciousness”(
–  A_empts(to(resolve(debate(between(raJonalism(and(empiricism(