Goals of Natural Science (1984)

8/13/2019 Goals of Natural Science (1984)

1/29

The Goals of Natural ScienceAuthor(s): Ernan McMullinReviewed work(s):

Source: Proceedings and Addresses of the American Philosophical Association, Vol. 58, No. 1(Sep., 1984), pp. 37-64Published by: American Philosophical AssociationStable URL: http://www.jstor.org/stable/3131557.

Accessed: 29/01/2013 18:05

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at.http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of

content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact [email protected].

.

American Philosophical Associationis collaborating with JSTOR to digitize, preserve and extend access to

Proceedings and Addresses of the American Philosophical Association.

http://www.jstor.org

This content downloaded on Tue, 29 Jan 2013 18:05:03 PMAll use subject to JSTOR Terms and Conditions
http://www.jstor.org/action/showPublisher?publisherCode=amphilosophicalhttp://www.jstor.org/stable/3131557?origin=JSTOR-pdfhttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/stable/3131557?origin=JSTOR-pdfhttp://www.jstor.org/action/showPublisher?publisherCode=amphilosophical


2/29

THE GOALSOF NATURALSCIENCE*ErnanMcMullinUniversityf Notre ameAs I ponderedhechoiceof topicforthis ntimidatingccasion, reflectednthechoices hatothers eforemehave made. One,in particulartoodout inmymind. It was Lewis WhiteBeck'sunexpectednd quite delightful971 address,"Extraterrestrialntelligentife".1 Onereason remembertso well sthat he opicis one thathas always nterested e,and one to which ontemporaryhilosophers(unliketheirforebearsn earlier enturies) ave had little o contribute.AnotherreasonwasBeck'sforthrightcknowledgementhat,n his ownwords, ifthispaperwere not thepresidentialddress, doubt hat twouldbe accepted ytheProgramCommittee".2He had clearly rasped,what others aveperhaps ailed o see,thatan occasion ikethis s not to be wasted;t is a once-in-a-lifetimehance o do ustas one pleases,withouthaving o worry bout thecold scrutinyf commentatoror referee.There s one furthereasonwhy thought eck'schoice peculiarlyppropriate

one. He directed urminds nd imaginationso distant orizons; e evoked ome-thing f that enseofwonder hat edall of us intothis xtraordinaryrofessionnthefirst lace. The faculty fwonder s as easilyost nphilosophy,fear, s it isin otherpursuits here odiesofknowledgemust e learnt ndtechniquesmustbeexercised.Weall needremindingowandthen fwhywe ever hought ith xcite-ment of this ancient nterprise,n enterprisehattoo easily odaycan become aStonehengeurroundedy high-risemodernofficebuildings,r worsestill, ustanother fthosehigh-riseuildings.Lewis Beckchallengeds to imaginewhatthefar eaches fspacemaycontain.I wantto do something oretraditional,nd,I fearmorepedestrian. nstead fvoyagingn space,I planto voyage n time, hough littlefurther,erhaps,hanphilosophersre wont to voyage. Thevoyagewillbe inthe form f a story, sagaofsorts.Theold Norse torytellersouldrecall heiristenerso theexploits f theheroes f old, their ncestors,romwhosevirtues nd failingsach newgenerationwas expected o learn. My sagawill notbe quite o dramaticrdirect. But therewill be heroes, ome of thempeoplewhosenames renowforgotten.Andtherewillbe achievements,reat chievements,hichwe, the nheritors, ust abor notto take forgranted.Theancient tory-tellersllowed heir tories ospeakfor hem-selves. Philosophersarely o. So youwillforgive e, know,f endbydrawing

*Presidentialddress eliveredefore heEighty-secondnnualWesternivisionMeetingftheAmericanhilosophical ssociation,incinnati,hio,April 7, 1984.

37

This content downloaded on Tue, 29 Jan 2013 18:05:03 PMAll use subject toJSTOR Terms and Conditions
http://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsp


3/29

38 APAPROCEEDINGSsomemorals.You wouldbe disappointed,reassuremyself,f did not. My tory,as youhavealready uessed,s to beabout heoriginsf that omplexndportentoushumanctivity esomewhatnelegantlyall"doing cience".

1. Thebeginnings:abyloniaIfone searchesnthe ancientworld or hefirst races f what necould n someplausible ense call science, ttentionmmediatelyocusses n tworegions, aby-lonia and ancientGreece. Historians aveputforwardrioritylaimsforeachoftheseareasas theoriginalradleof science.AsgarAaboe,for xample, rgues hattheWesternraditionnastronomysentirelyerivativerom abylon:

Mathematicalstronomyas,however,otonly heprincipalarrierandgeneratorf certainmathematicalechniques,ut tbecame hemodel or henew xact cienceswhichearned romttheir rincivalgoal:togive mathematicalescriptionfa particularlassof naturalphenomenaapable fyieldingumericalredictionshat anbe testedagainstbservations.t s nthis ense hat claim hatBabylonian athe-maticalstronomyastheoriginfallsubsequenteriousndeavorntheexact ciences.3On theother and,Geoffreyloydwrites:Thedevelopmentfphilosophynd sciencen ancientGreece s aunique urning-pointn thehistoryfthought. o far s theWesternworld oes, ur ciences continuous ith,ndmaybesaidtoorigi-nate nancientGreece.4

The sourceof the apparent isagreements not hardto discover.Aaboe andLloydhavetwoverydifferentonceptionsfsciencenmind, ndit is indeed ruethatone of them an be traced ackto Babyloniandtheother o ancientGreece.It willbe instructiveo seehow eachoriginated,ndthenwhy heyremainedepa-rate, mbodiedn differentommunitiesinastronomy,t least)until he17thcen-tury.The Babylonianideof thestory an be saidto begin omewhereboutthetimeof Hammurabin the 18thcentury .C. Accordingo thecuneiformablets, heBabylonianselieved hat thegodscommunicatedo menbymeans fomens, othin thesky ndon earth.5Theoldest istofcelestialmensdealswithunar clipses,but ater nesrefer,or xample, o the imes f firstr ast ppearancef themoon,of theplanets nd of certain rominenttars. Thesephenomenawereregardedsmessages,s specialcommunications,rom hegods;theability o interprethemallowedone to anticipatevents n earth, olitical hanges, ropfailures,nd thelike.6 How the listswerefirst uttogethers unknown,utthey apidly ecamesort of "canon",theEnumaAnuEnlil,an authoritativecribal radition hich e-mained irtuallynchangedver hecenturies.7Thetypical menwill pecify celestial onfigurationnd thengoon toassociatewith t somesignificantvent n earth;If thestars f the TrueShepherd fAnu(i.e. Orion)scintillate,n importantersonwill becomepowerful,ndcommitvildeeds". There s no record,however,n thisearlyperiodof actualobservations.



4/29

PRESIDENTIAL ADDRESS -MC MULLIN 39The omentextsmade no attempto predictwhenthecelestial henomena ouldoccur. Theyustspecified: hen hefollowingelestial onfigurationccurs,xpectsuch-and-sucho happenon earth. Nevertheless,he diviners hoseresponsibilityitwas to interpret,xtend,nd handon the textsmusthavebeen alert ochangesnthesky. Therewouldhavebeen strongmotivationotry ocataloguehesenordereventuallyo predictuchomensigns s lunar clipses. Althoughhere s a crudeastronomicalable entitledMUL.APINorPlough tar)dating rom round 100B.C.which, mong ther hings,hartshemoon'spath hroughhe 17 constellationsftheecliptic henrecognized,he realbeginningsfobservationalstronomyrenotfound ntil he eventhentury.C.8The phenomenaf interest ere,of course, hesame onesalreadyisted n theomen exts ornearly thousand ears efore:unar clipses,ndhorizon henomenaof various orts ikefirst ightingsf planets ndconstellations. here s reason osuppose hatthepeoplerecordingheobservationsere hesame s thosewhohadbeen for o long ncharge fthe nterpretationfomens.9Yet there oesnot eemto havebeenanyattempto improveheaccuracy ftheastronomicalescriptionsgivenn the omen istsof theday. Newcopiesof the ists till nclude eferencesto lunar clipses n the 21stdayofthemonthr toeclipseswherehe hadowmovesfrom ight o left cross hemoon'sdisc. By thistime, he omenscholarslmostcertainly new that neither f theseconfigurationsan occur. It was evidentlyhighlyonservativeradition.The greatperiod n Babylonianstronomyomesquite ate,duringheSeleucidera from 50 B.C. - 50 B.C. At thispoint, heastronomyecamefully redictive,utilizingmathematicalechniques eveloped millenniumnd a halfbefore,10nddrawingpresumably)n a traditionfplanetaryndlunar bservationhatbynowspannedseveral enturies. Ephemerides ereconstructed,nabling he timesofoccurrenceo be calculated orthevarious orizon henomena,s wellas for unareclipses. For eachtypeofcelestial henomenon,setofnumericalifferencesasspecified; ecausethe apparentmotions f sun,moon,and planets re irregular,complexprocedures ererequiredn order o extract recurrentrderfrom heobservationalecords.11 No attempt as madeto follow hepathof theplanetsnthesky. Only he"significant"oments ere reated, amelyhefirstppearancesof theplanets ver hehorizon,he astsightings,nd thestationaryoints;tseemsplausible o regardhisrestrictions an echo of the omen raditionnwhich heseandonly hesemoments ere ingledut.The goal of Babylonianstronomy asprediction,othingmore. One can seeeasily nough owthisgoal might avebeen inked o an earlieret ofquestionshediviners ouldhavewrestledwith. Theywould havewanted o know n advancewhen heomen-eventsere ikely o occur. Thedesirabilityfsuchknowledge usthave beenevidentongbefore hetechniquesor tsrealizationradually egantobe forged.ndeed,what trikess now s the engthf timet tookfor his ohappen.Desire, eed, nterest,sobviouslyotenough.What hediviners ouldnot haveaskedwaswhytheheavenlyodiesmoved stheydid. If thesky s a celestialmessage-board,heactualmovementsfthemoonand planets re not significant.Onlythe configurationst the "message"timescount. Perhapshismayhelpto explainwhy he stronomersfBabylonpparentlynever oughthecausesoftheplanetary otions,ven ncontexts--thinkf the unar



5/29

40 APAPROCEEDINGSeclipse--wherecausalunderstandingouldhaveaided nprediction.ftheirstron-omy s to countas science--andhattoo is a question heywouldnot haveraised-it mustbe on the scoreof tspredictiveower,ts observationalasis, tscomputa-tionaltechniques. It has no theoreticalimensions natural cience; t makesnoattemptoexplainwhy hecelestial odiesmove sthey o.12Let us call this ortof system P-science. tsgoal s to organize henomenaseconomicallys possiblewith viewto exactprediction.Predictiveccuracy ndoperational onveniencere, therefore,he criteria ponwhich t is to be judged.Its predictionsn turnmayservepracticalnds, o thatP-sciences likely o havea practicalswell s a cognitiveoal.

2. Thebeginnings:reeceWecan turnnowto morefamiliarround.At a timewhentheBabylonians erestill crutinizinghe skiesforomensof whatthegodswouldbringbout on earth,their eighborso the Westwerebeginningo do almost xactly heopposite.Theywereformulatingonnected otions fnature nd of causewhichwouldmaketheworld ntelligiblen its own terms.No message rom hegodswouldbe needed;their nterventionnthe affairsf menwouldnot be excluded utwouldeffectivelybe minimized.Things avea nature, regularmodeofacting,nd a properly-con-ducted nquiry an reveal heprinciplesfthisnature.Thegoalofsuchan inquiryis to understandhenature,o graspwhy hechangesnquestion ccur s theydo.

The political ifeof the Greekcity-state,istoriansemind s,was suchas tofavor penand critical iscussion.Opinionswerechallenged; roundswere oughtfordisputed iews.Radicalpolitical ebate edto thequestioningvenof themostfundamentaleligious eliefs. The outcomewas occasionally cepticismutmoreoftena sophisticatedppreciation f the argument-structuresppropriateo theclaimbeingmade. The topicof argumenttself, ialectic, ameto be discussedtlength. Lloydremarkshatphilosophynd science can onlybeginwhen setofquestionss substitutedora setofvaguelyssumed ertainties",ndso "theymaybe representeds originatingrom heexceptionalxposure,riticismndrejectionofdeep-seatedeliefs".13Thedominantuestion ecomes heepistemologicalne:whatkind fknowledgeanyouclaim?Thefirst istinguishingark fscience, s the Greeks ameto definet,wasthusthequality ftheknowledgetembodies.Epistemes the best n thewayofknowl-edgethat can be attained. Aristotle awno reasonwhy t couldnotbe "eternaland necessary",s geometryeemed o be, and so the deal of a definitivecienceof naturewas born.Such sciencewouldbe demonstrative.t would est npremisesintuitivelyrasped s true, nd proceedby deductiveule. The first xplicit oalis thereforeertainty;hough he scientistmustmakeuse of dialectical easoningalong heway, heresnoplacefor t n thefinishedtructuref the cience.Thesecond haracteristicf science s to be its search or auses. Historiansavenotedthatthe Greek erm,aitia,'which ameto havethequasi-technicaleaningamongphilosophersf cause,wasoriginallyterm enoting ersonal esponsibility.To ask forthe aitia of an actionwas to ask: whois responsibleor t? In certaincontexts,t couldmean:who s to blame?who s guilty?14The convictionhathadanimatedoniansciencewas thatevery venthas a cause,or as Leucippusputit:



6/29

PRESIDENTIALADDRESS - MC MULLIN 41"Nothingomes o be atrandom,uteverythingor reasonndbynecessity".15A second ource f this onviction as the medical radition. loyddraws tten-tionto theopeningwords fthetreatise, n theSacredDisease,dating romround400 B.C.:

I do notbelieve hat he acred isease epilepsy]sanymore ivineor sacred han nyother isease ut, n the ontrary,ust s otherdiseases ave nature rom hich hey rise, o this ne has a nature(physis)nd a definiteause prophasis).16Andat the end of thework, hewriter'srogramormedicinesmadeevenclearer:"Each [disease]has its ownnature nd power, nd there s nothingnanydiseasewhich s unintelligiblerwhich s not susceptibleo treatment."17 thermedicalwritersn the Hippocraticorpuswenton to specifyhe notionof causefurther:

Wemust,herefore,onsiderhe auses aitia)ofeachconditionobe those hings hichre uch hat,when hey represent,he on-dition ecessarilyccurs, utwhen hey hangeo anotherondition,itceases.18Aristotle's octrine f four causes",or four omplementaryaysofexplaining

change,s too well-knowno needcomment. Thecausesbeing our", e remarks,"it is thebusiness fthephysicisto know bout them ll".19 Thegoalof naturalscience s thusto grasp hecausesofchange,o explaint interms foneorotherofthe four anonicpatternsfexplanation. will allAristotle'sdealnatural ciencea D-science. tsgoal s a knowledgefcauses,where nowledges construedsdem-onstrationndcauses rethoughtobedirectlyrasped.Prediction laysno particularole n a D-science.Testings notneeded, incethepremissesre ntuitivelyeento be true ncetheironstituentonceptsregrasp-ed. Of course,f thenature f a beings understood,ne willbe ableto "predict"what henormalctivitiesf thatbeingwillbe. Butthis s predictionnlyna veryweaksense. There s no suggestionhat goal ofthesciences to enableus to dis-cover omeoutcomewewouldnototherwiseaveknown.Thegoal scontemplatite,a theoria, ot n thesenseofbeing onstructednisolation romxperienceAristo-tle's D-sciences construeds resting irectlyponexperience),ut nthesenseofitsbeing n ntellectualrasp,nunderstanding,fsomepart fnature.Did PlatoandAristotlegnore heclaims f P-sciencentirely?Theastronomyof Plato'scontemporariesad notyet really ttained nypredictiveower, o thequestion id notperhapsrise orhimdirectly. is treatmentfobservationalstron-omy s, nevertheless,uitepuzzling.Accordingo Simplicius,e is willingo allowthat astronomers ay "save the phenomena" y usingcombinations f circularmotions.20But n theRepublic,he appears o contrast his ortofastronomy ithwhathe somewhatmysteriouslyalls "real" or "true" stronomy.21 bservationalastronomyannotqualify s knowledge,e insists: If anyone ries o learn boutthethingsfsense,whetheraping p orsquintingown, wouldnever aythathereally earns;fornothingf the kindadmits f trueknowledge".22Eventhoughthestars nd planets re "the fairestndmost xactofmaterialhings",wemust



7/29

42 APAPROCEEDINGSrecognizehattheyfall far hort f thetruth,he movementsamely frealspeedandreal slownessn truenumbernd n all truefigures.. These anbeapprehendedonlyby reason and thought, ot by sight".23 Predictivestronomyan at bestserve nly s propaedeutic.But,as Vlastoshas argued,he notion f thediagrams propaedeutichat ervesPlato owell ngeometryailsnastronomy:

Whateverruthmaybepicturedn a geometricaliagram,hefact hatit spicturedhere asnoevidentiaryalue.... Inastronomy,ntheother and...what an be seen n thevisible eavenss ndeed reason--inthe ast nalysis,hereason--whynastronomicalheorys true.24Does Plato really eek an astronomy hichwould not reston sense-observation?Or is he onlysaying hatreasonhasto contributehegeometriciguresnterms fwhich heobservationsanbe convertedntoa propercience?Hispupils ppear ohavetakenhim nthis atter ense, utthetextswe have reat bestequivocal.Andhis assertion hat t is pointless or he observationalstronomerto striveo deter-minethe truth aboutthestars]by every ossiblemeans,"25 uggestshathehadfailedto graspthe importancef the highest tandardsf observationalccuracyattainable. All in all, then, t seemsfair o conclude hatPlato'sviewson sense-knowledgelockedhimfromakingeriouslyhenotion f a "science"whichwouldhave mpiricalccuracys a primaryarrant.

Aristotlemade a more successfulffort o incorporatehetroublesomecienceofastronomynhis account fnatural nowledge,ut n the endhe failed lso. Hedevotes chaptern thePhysics o the differencesetween hephysicistnd themathematician,nd gives ver stronomyo the mathematician. hosedisciplineswhich make use ofmathematicsn theirdiscussionsf nature--heistsoptics,har-monics, nd astronomy--are,e says, he "morephysical f thebranchesfmathe-matics",26 ot as onemight aveexpected) hemoremathematicalarts fphysics.Sincetheydraw heir rinciplesrommathematics,heypertainmore roperlynhisview o mathematicshan o physics.And sincehe is insistingn a fundamentalis-tinction etween hysicsndmathematicsn the scoreof(among ther hings)heirdifferingevelsof abstractionrommatter,hosedisciplines hich semathematicalmethodsndiscussinghysicalopics eemnottofit roperlynywheren his chemaof thesciences.27They eem o be uncomfortablyntermediate,mixed"or "mid-dle" sciencess theywill ome o be called ater.Butwheredoes this eavehisphysics? s he interdictedrom singmathematicalconceptsn it? It does notseem o;they ccur requentlyn thepages f thePhysicsandtheDe Caelo. Andhe himselfemarkshat twouldbe absurd or hephysicistto try o discoverhe naturesfthesunor moonwithoutakingnto ccount heirsphericalhape.28 Yet ifhe cannotncorporatehe resultsf mathematicalstron-omy ntohis accountof theplanetarymotions,whatsortof science an hehave?It is at thispoint hat hetensions etween -sciencend D-science omefullyntoview.Aristotle erived isastronomy ainly rom udoxus c. 408-355B.C.) whowasthe first o try o accountfor hepaths f thesun,moon, ndplanets,n terms fcombinationsf circularmotions. Each of thesebodieswasassigned separate etof spheres,hefirstwo ofwhich n each casewouldhavethesamemotionssince



8/29

PRESIDENTIALADDRESS - MC MULLIN 43theywereessentiallyccounting orthe earth'sdouble motion f rotation n itsaxisandrevolutionround hesun). Themoon nd sunhadone more phereachtoaccountfordeviations rom he ecliptic;29 he fiveplanetsweregiven wo morespheresachto account or heirrregularandespeciallyheir etrograde)30otions.Each planet hushad a cluster f four pheres,eachrotatingt a differentpeedaround differentxis,to explain tsmotion. Each spherewas "carried" n thesphere extoutsidet, owhichtspoleswere onsideredo beattached;heplanett-selfwas treateds thoughtwere ttached o the quator f the nnermostphere. tseems nlikelyhatEudoxus ver ucceedednusing his ngeniousmodel opredict,except n a very oughway.31 Butwhathe did succeed ndoingwas to suggestmechanism herebyhecomplexrregular otions fsun,moon ndplanets,mightina general aybeunderstood.32Aristotle ookoverthesystemfEudoxus s amended yCallippus,33nd triedto unifyt intoa single ynamicystem.He apparentlyound he Eudoxanmodeldefectiveecausetallowed achplanet ofunctionndependently:

It snecessary,f llthe pheresombinedretoexplain heobservedphenomena,hat or achof theplanetsherehould eotherpheres(onefewer han hosehithertossigned) hich ounteracthose lreadyspecified,ndbring ack o the amepositionheoutermostphere ftheplanet ituated elow. Foronly huss tpossible or hewhole ys-tem oproduceherevolutionftheplanets.34The "counteracting"pheresddup to 22 extra, iving im55 in all. Their unc-tion s to allow thecluster f spheres ertainingo one planet o be connectedothe nextone below t without ommunicatingo the atter tsownmotions; nlythesinglemotion f thesphere f the fixed tars s to be carried ownthroughout.Aristotleivesno furtheretails fthesystem,nd t is notatallclearhow twouldwork.35 He obviously houghthattheenormousncreasen complexitye wasproposing as offset y theunificationf thesystemnto singlemechanism,ndbythepromisehis ave f a completemechanicalxplanation.A mechanicalxplanationracingll motionupward o a FirstMover ouldnot,

infact,work.36Perhapshis swhyAristotlentheMetaphysicsries quitediffer-ent model n whichmotion n thecelestial ealm s broughtbout not by contactbut by desire, nd a separateUnmovedMover s associatedwith ach sphere, hespheretself eing ssumed o be capableof desire.37 Thisrepresents,ncemore,an enormousncreasen complexityver hesimple osmologyf thePhysicswhichterminatesidilyna singleMover or hecosmos s a whole. Onecan seehowhigha priceAristotle aswillingopayfor model hat, t east nprinciple,ould ctual-ly explain38whythesystem orked s itdid,even houghhestyle fexplanationused had to be an unhappy lendof themechanicalndtheteleological:onlythusis tpossible or hewhole ystemoproduceherevolutionftheplanets".39Aristotleeems o havebeenawareof the imitationsf theawkward nionhewas attemptingetweenin ourterms)D-science ndP-science.A D-science ughtto "concludewithnecessity".Buthowcould a model hatdependednthe umula-tiveresults f observations wellon the ngenuityf thegeometerverdo this?In his owncountof thespheres,fter roposing5 as the total ndthen ddingproviso hat47 might o, he concedes hatthis s only"probable": theassertion



9/29

44 APAPROCEEDINGSofnecessitymust e left o a morepowerfulhinker".40Andthenwith returnohis characteristiconfidence, e adds: whateverhenumber f the spheres, hismustbe the numberf UnmovedMovers. Andsince llmovements ust race ackto suchMovers,theend ofeverymovementillbeone ofthe elestial odieswhichmove hroughheheaven".41This s an enormouslymbitiouslaim. In retrospect,t is easyto see howvulne-rable twas,and ustwhy t wasso vulnerable. heexplanationst suggestsadanintuitive lausibilityo them: fter ll,contact ction ndresponseo desire rethetwo sources f motionwe can most asily dentifyneverydayife. Buttherewasnoreal testingf these nsights;herewas no waythat provisionalnsightouldbesystematicallyvaluated;herewasno source f nsightaveordinary id-levelumansense-experience.n consequences, hentherewas a conflict etween hefindingsof D-science nd P-science,herewas no wayto arbitrate.Aristotle ad foundtemporaryay opatch hedifferences.ut tcould astonly ntil -scienceevelop-ed sufficientlyor t to become mpossible oreventhe most ngenious -scientisttohookthe wotogether.42

3. Asciencef stronomy?Overthe nextfew enturies,rogressnastronomyas slow becauseof thediffi-culties n making nd compilingbservationsf the accuracy equired,nd evenmore becauseofthedauntingomplexityfthesphericaleometryeeded o bring

the observationsntoa single rder. The most ignificantevelopmentas the ntro-duction yApolloniusndHipparchusf two lternativeso theconcentriceometryof Eudoxus. These weretheeccentric nd theepicycle,43achofwhich mploystwo uniform ircularmotions nsteadof one, so thatthere s a secondcenter frotationn thesystem, mathematicaloint-centerf no apparent hysical ignifi-cance. Theirmain dvantage as that hey llowed hedistance nd hence hebright-nessof theplanetsovary eriodically,hich he oncentric odeldidnot. Since hebrightnessariations ereknown, ven n Aristotle'sime, his failure f thecon-centricmodel came to be recognizedmong stronomerss a majorfault f theAristotelianystem.44By thistime, he tensions etweenD-science nd P-sciencewerecoming o benoted.Writingnthefirstentury.C.,Geminusssertshat:

Thephysicist illprove achfactbyconsiderationsf essence r sub-stance, fforce,f tsbeing etter hat hingshould ethus, r ofcomingntobeing ndchange;he stronomerillprove hem ythepropertiesffiguresrmagnitudes....orexample, hydothe un,themoon, ndtheplanetsppear o move rregularly? emay nswerthatfwe assume hat heir rbits reeccentricirclesrthat hestars escribenepicycle,heirpparentegularityillbe saved; utthentwillbenecessaryogofurtherndexaminen howmany iffer-entways t spossible or hese henomenaobebroughtbout, othatwemaybringur heoryoncerningheplanetsnto greementwith hat xplanationfthe auseswhich ollows nadmissible[physical]method.45



10/29


11/29

46 APA PROCEEDINGSeach other"49),but he clearly egardshem s no morethancorroborative. hemainweights tobe onthefit etween heobservationsnd thehypothesesroposed.The observations eed not be astronomicalnes. In fact,n one significantnstancehe allows the terrestrialbservationso overrulein a way) the celestial nes. Heallows that it would be a "simpler onjecture"50 o havethe earthrotate n itsaxis,presumablyecause t would implifyheastronomical odels. But thishypo-thesishasto be rejected, e says, n thegroundsf oureverydayxperiencefmo-tionson theearth's urface, return o the more onventionalphysical" rgumentsofAristotle.ThecausalcharacterfD-science as alsohad to be sacrificed,muchmore eriousloss. Though e frequentlyaysthat hecircularmotions e attributeso theplanetsare"bynature", isepicycles adno plausible ausal nterpretation.urther,ehadto placethe center f theplanetaryeferentircles t an eccentric oint wayfromtheearth, nd worst f all, supposethatthemotion f the center f theepicycleon the deferentircle s non-uniform,51husgiving p the astremnantf theuni-form ircularmotion n which he old D-sciencefastronomyadbeenbuilt. Bythe timethe astbook of theAlmagests reached, tolemys pessimisticboutthecost in terms f simplicitynd of causalplausibilityhat hepredictiveriterionfsaving he appearances as entailed.52 No one ought o objectto the "devices"he has had to use,he saysdefensively,ecause he same orts fcriteriaughtnotbe appliedto celestial s to terrestrialodies, incetheformermovewithout nyresistancerom he ether:

Rather,ne should ry,s far spossible ofit he impler ypothesestotheheavenlymotions,ut fthis oesnot ucceed, oneshould pplyhypotheses] hich ofit. Forprovidedhat ach ofthephenomenaisduly avedbythehypotheses,hy hould nyone hinktstrangethat uch omplicationsan characterizehemotionsf theheavenswhen heir atures such s toaffordohindrance,utofa kind oyield ndgivewayto thenaturalmotionsf eachpart, ven f[themotions] reopposed oeachother?53So we are back to pureP-sciencegain,one that, s Ptolemynsists, oes giveus a truth boutthings,venthough heclaimto explanatoryowerhasbeenvir-tually bandoned. Thereare no carryingpheres,nlycircularmotions,omeofthemof imaginaryoints r around maginaryoints. The phenomena avebeensaved,54 utthedevices sed cannot e interpretedausally.And theonly vailablecausalsystem,hatofAristotle,as beenrefuted,incethasfailed osave hepheno-mena. FromPtolemy's ointofview, ne is notat libertyo use both ystems,neforpredictionnd one forexplanation;heconcentricmodel s simplywrong nhiscriteria.In Sozein ta Phainomena, irst ublishedn 1908,Pierre uhemhailsthe nstru-mentalisme claims o find verywherenHellenisticstronomys providinghis-torical ntecedentorhisown accountof physics.He describeshe egacy fthisastronomysfollows:



12/29

PRESIDENTIALADDRESS -MC MULLIN 47Astronomicalypothesesrenot udgementsearingn thenature fthings;t s notnecessaryhat hey ededucible romheprinciplesofphysics,or ven hat hey einharmony ith hese rinciples;tis notnecessaryhat hey llowofrepresentationymeans fsuitablyarrangedigid odies evolvingn oneanother,ecause sgeometricfictionshey aveno functionxcept hat fsavinghe ppearances.55

Recent scholarshave questionedDuhem'spenchant orreading much aterversion f instrumentalismnto texts thatdo notreally ustaint. Specifically,wouldwant o argue hathisattempto construetolemys an nstrumentalistoesnot do justiceto the latter's oncern o make of mathematicalstronomy trueaccountof things,o far s thiscan be obtained. Butthemerit fDuhem'sbookis to document,ven f in a somewhat artisanway,thedeep separation etweenexplanationnd predictionn the only partof pre-Galileanatural ciencewhereprediction asatalldeveloped.Duhem, s one wouldexpect, s unsympathetico thosemedievalwriters,heArab andJewish hilosophersn particular,ho frettedbout thefictionalistead-ingof theepicyclesndfound omethingrongnthisfacile eparationf thefunc-tionsof causal explanationnd mathematicalrediction.Averroes,orexample,argued hat properystemfastronomyught ontain othinghat s "impossiblefrom hestandpointfphysics".Ptolemy,egoeson,"wasunable o set stronomyon tstrue oundations":

Theepicyclend the ccentricre[physically]mpossible.Wemust,therefore,pply urselvesoa new nvestigationoncerninghatgenuinestronomyhose oundationsreprinciplesfphysics...Theastronomyftodaysconvenientor alculation,uthasnothingtodo withwhat s.56We wouldbeinclinedosaythatAverroes asperfectlyightorequirenastrono-my o be inharmony ith asicphysics.Duhem uggestshat heemphasisnspheresand the ikeon thepart f theAristoteliansasno more han concession o that

inveterateumanweakness ormechanicalmodels hathe findsqually bjectionablein medievalArabastronomynd 19thcenturyritishhysics.ButAverroes'ointrunsdeeper hanthat:he is insistinghat n astronomical odel deally houldnothaveto resort o fictions,hat t shouldbe inharmony ithwhat s known fthecausesnvolved.ForAverroes,quinas,ndothermedieval hinkers hodiscussedhis iscrepancy,what made t especially ifficulto allowthatphysics ould earnfromstronomywas their learperceptionhat n astronomyne had to argue rom ffect ack tocause. In suchan argument,s Averroes ut t,"theprinciplesre hidden rom s[and] are nnowaynecessitatedytheknown ffects".57Butthis s ncompatiblewiththat otherfeature f D-science,hedemand hat nference e demonstrative,that tproceed rom ause oeffect. In astronomy",quinas emarksnthe ummaTheologica:weaccount or picyclesndeccentricsythefact hatwe cansavethe ensibleppearancesftheheavenlymotionsythishypothesis.



13/29

48 APA PROCEEDINGSBut his snot really robativeeason,ince he pparentmovementscan,perhaps,e saved ymeans f some ther ypothesis.58

Whatsstrikingo usnow s we ook back tthe ong ecordfastronomyetweenPtolemy nd Galileois how little henatural hilosophersorriedboutthe factthattheir pheres ackedany sortof predictiveorce nd howlittle oncern heastronomersn their urn howed boutthefact hat heir picycleswere ncompa-tiblewiththecausalprinciplesfthe bestphysics ftheday. It wasnotas thoughthephilosophersouldhave been unaware hata true ccountof the causesoughtalso be predictive,r thattheastronomersould havebeen ndifferento whethertheirgeometrical odelsrepresentedealmotions r not. But eachsidebracketedthe awkwarduestions,nd went bout tsownbusiness,s professionalsresupposedtodo.4. Theoreticalcience

I am going o proceed mmediatelyowto the denouement ouhave beenex-pecting, he coming ogetherf explanationnd predictionn thenewscienceofthe 17thcentury.Since thispartof the storyswellknown, can (at last)affordto movequickly. Focussing n astronomyirst, our tages an be distinguished.First, opernicus'stronomyas still aughtn thePtolemaic ilemma:tpredicted,planetary otions utdid notexplain hem ausally.AndCopernicus asnot will-ingto acceptthefictionalisttatusforhisastronomyhat o many fhispredeces-sorshad settled or. Thoughhissystem ad clear xplanatorydvantagesver hatof Ptolemy, e couldnotgive causal nterpretationf theepicycles e was stillforced o use. NorcouldGalileo,whothough ehadsuccessfullyndercut ristotle'sphysics, ad notyetbeenable to fashion n alternativeausalaccount f hisown.His unionof celestialwithterrestrialhysics aveevery eason o expectthatthelong eparationetween hysicsnd mathematicalstronomyasover. But t musthaveseemedhopeless o try o explain picyclicmotion ausallyf even he implestnotions ffallwere s yet onlydescribed,ot accounted or n causalterms. t wasunclear o Galileohow causalexplanationhouldproceed n mechanics,o in theinterime builthiskinematicsithoutt.It was Keplerwho finally id awaywiththeepicyclesnd the eccentrics,ndthemathematicalonstructf a "mean sun" whichCopernicus ad been forced opostulates the center fhisplanetaryystem.By showinghat heplanetaryrbitswereelliptical, e made t plausible hat single ortof causalactioncenteringnthe sunmight e responsible.And twasNewton, fcourse,whocarriedhis pecu-lationthrougho the evelofscience.But whatkindofscience?Somethingftheold ambiguitytillremained.Newton's elestialmechanics asassuredlyredictive.Butwas texplanatory?Manyofhis critics idnotbelievetwas. They rgued hathisconcept f attrac-ton did not really xplainwhytheplanet ircled he un. Berkeley asconvincedthatthe new mechanics as a P-science, o more; t gaveno causalunderstandingof motion t all in hisview. EvenNewton imselfnthePrincipiaskedthereaderto lay aside the question s to what sortof causesthese ttractions ere, nd tofocuson thedescriptive athematicse had provided orthemotions. Weknow



14/29

PRESIDENTIAL ADDRESS -MC MULLIN 49enough fNewton's wnthinking,owever,o be sure hathe didtakehisdynamicsto provide causal account venthough e realized ullwell thathis forces ouldonlybespecifiedhroughheirffects.59If the onlynatural ciencesweremechanicsnd astronomy,t would be hardto decidewhat sortof science esultedromheunion nNewton's rincipiafthetwodisparateinesgoingback overthecenturieso Babyloniandto Greece. Butfortunatelyherewere othernatural ciences ven n the 17thcentury,nd it ismucheasier o decide n thecase of theotherswhatthegoalsof thenewsciencewouldbe andhowthey elate o thoseof theD-sciencendP-sciencehatprecededit. Let me retracemysteps ust a littlefirst. The reason hatnatural hilosophersin theAristotelianraditionadtended o regardheepicycles fPtolemys fictivepractical eviceswas notmerely ecause heywere rrivedt inhypotheticalashionor becausetheywerethought o be predictivelyquivalento otherpossiblegeo-metricalmodels. It was becausetheywere ncompatible ithwhatwasthoughtobe thetrue xplanatoryccount, heD-science f concentricpheres.60Neverthe-less, t is true o saythat twas nastronomyhat he ssue fthevalidityfarguingfrom ffect ackto cause in a hypothetical aywasmost quarelyoined,as thefamous exts n thePosterior nalytics bout the non-twinklingharacter f theplanets nd themanner fwaning fthemoon lreadyndicated ightt thebegin-ning f the tory.The moregeneral ssue of ex suppositioneor hypotheticalr consequential)reasoningwas extensivelyebated hroughoutheRenaissance. Butwhatblockedany sort of resolutionwas the fixedpresuppositionhat omehow heequivalentof a demonstrationad to be reached, hat heregressusromffecto causemustbe madeto yield hesort fcertitudenecould mmediatelyave na propteruidargumentromauses oeffect.The turning-pointaybe saidtohave comewithDescartes.Hisexperience ithsuch sciences s optics,meteorologynd physiology,onvinced im, o quote thefamousines romheDiscourse nMethod,hat:

Thepower fnaturesso ample nd sovast, ndthese rinciples[ofmy cience] o simplendsogeneral,hat almost ever oticeanyparticularffectuch hat donot eerightway hattcanbe derived romhoseprinciplesnmany ifferentays.61

Sinceeach of thesedifferentaysyields differentause,demonstrations im-possible. Thisconclusionwas reinforcedy thetheological oluntarismhich edhim(as it had donemany arlier hinkers)o assert hatGod couldhavebroughtabouttheeffects e perceiven an infinityfcausally ifferentays. What,hen,was tobedone?I knownoother xpedienthan gain osearch or ertainxperi-mentswhichre uch hat heir esults notthe amewhenweexplain he ffectyonehypothesiss whenweexplaintbyanother.62



15/29

50 APAPROCEEDINGSBaconhad already hown n muchmoredetail n theNovumOrganon ow thissortof systematicxperimentalestingfhypotheses ight e carried ut. And asthecentury oreon,thismethod fworkingackfromffecto causalhypothesis,which s thentestedby drawingonsequenceshatcan be observationallyhecked,becamemore ndmore henorm noptics,n chemistry,n thephysicsfgases, ndelsewhere.But therewere two reasons,n particular, hythemethod fhypothesis asgradually ecognizedo be required,whythe hesitationsf the centuriesn thepart fthosewho heldout for demonstrativeciencewerenowso firmlyet side.The firstwas thetelescope, n almost ccidental iscovery,ccidental t least nitstiming elative o otherdevelopmentsnthoughtt the time. It raised ssues boutthenature fdistant bjects,ikesunspotsrcomets r lunar hadows,which ould

not possibly e handled n anyother han hypotheticalay. The conditionsoran Aristotelian-science learly ouldnot be realized, ince an intuitiverasp fthesedistant atures ouldin no waybe attained. Onlya hypotheticalrgument,testedby the predictionsrawnfrom t, and not by anyquality f self-evidenceorperceivedecessity,ould uffice.Evenmorefundamental as the almostuniversallyhared onvictionhattheperceived ualitiesof things ad to be explicable n terms f minute orpuscles,themselvesmperceptibleo us. It is noteasyto explain ustwhy his orpuscularphilosophyo quickly ookhold nthe seventeenthentury,ince thad as yet andindeedfor longtimeto come)no really estable onsequences.Butthesuccessof thenew mechanicsmade t plausible hat fthemacro-propertiesf bodieswereto be explained t all, it wouldhave to be by postulatingn "invisible ealm", sNewton alled t,whosepropertiesnd motions ccounted ortheperceiveduali-tiesofthingsndthusmadethemnan ontologicalense econdary. t wasevidentto all that thisrealm ouldonlybe approached y the tentative ethods fhypo-thesis-testing.ndto themore mpiricist-inclinedhilosophersikeLocke, t seem-ed as thoughheprospectsf thisyieldingmuch n thewayofknowledge, erenotbright.Whatwe have n themaking ere s,ofcourse, new dealof science. Thegoalcan stillbe expressedn Aristotle's hrase s "a knowledgef causes",buttherearetwocrucialmodifications,ne n the ermknowledge'nd one n the ermcause'.The knowledgehat scienceyields s no longer iewed s demonstrative,s defini-tive, s necessary. t is probable, allible, ependentponcontinuedesting.True,thiswillcontinue o be disputed ntilwell ntothe 19thcentury,ot eastbecauseNewton'smechanicseemedto manyto provide t least one instance f an old-fashioned -science.Butthe notion hat estings needed, nd thus hatpredictionis nowa necessary artof science,was grasped, am temptedo sayonce andforall, already n the 17thcentury.No longer ouldpredictionnd explanation esundereds theyhad beenforso long. Now the main estimonyf an acceptableexplanationwillbe preciselyts ability o predict, hat s, to entail estable onse-quences. Notethat hiswasan empiricaliscovery;t had to be shown hat sciencefullyoining hegoalsofexplanationndprediction aspossible. It couldplausiblybe argued hatthis was one of the mostrevolutionaryiscoveriesn thatcenturyof"scientificevolution".The transformationn the notion of causewas equallyfundamental,utmoreambiguous.Tracingbservedffects ackto causesnotthemselvesbservedequired



16/29

PRESIDENTIAL ADDRESS -MC MULLIN 51a theory,nd ntime he notion fa "theory" ametomeanprimarilyheproductof this sortof retroductionrom ffect o postulatedause. The causein suchacase is defined ythetheory,nd ts warrants no more han, nd no lessthan, hetheorytself. The cause is thuswhat ame ater o be called "theoreticalntity".Theminute articlesf thecorpuscularhilosophy ouldbe "causes" nthat ense.Theybringbout, xplain, ause, he observedffects.They reagencies ostulatedfor hevery urposes fexplaining. heyresemble,herefore,he efficientragentcausesof the Aristoteliancheme;where heydiffers in being hidden", hat s,notgivennobservation. heymaybe constituentarts fthe ntity hoseproper-ties arebeing xplained, r theymaybe distant r imperceptiblentitiesike sun-spotsorethers, hosenature r evenwhose xistence anbe inferrednly na theore-tical r ndirect ay.Thenotions ftheoryndtheoreticalntityre thus entralo thisnewlymerg-ingmodelofscience,whichwe can call T-science. nT-science,hepredictiveowercharacteristicf P-scienceblendswith the explanatoryorcecharacteristicf D-science.There anno longer ea sciencewhichmerelyredicts,rone whichmerelyexplains. If it predicts ut without eing ble to specify causalsubstructure,tmaybe useful utit is not science n thefull ense. If tpurportso explain, utdoes not permit estable onsequenceso be drawn, here s reason o doubtthegenuinenessf tscausal laim.What onfused,nd to someextent, tillconfuseshe ssuewas a muchweakernotion of cause promulgated y Hume. Whatmakes omething "cause" in hiseyes s itsbeingnvariablyound o precede he effect nd to be spatially roximateto it. But forhim,both effectnd cause must e observable,ndto explain s nomorethan o pointto an antecedent hichn thepasthasalwaysbeen foundwiththisexplanandum.No placeherefortheoreticalntities r hidden gencies fanysort. Thewarrant or his rasticestrictionf the xplanatorybilityfsciencewas,of course,Hume'sradical mpiricism.63 uthis account fcause wouldhavemadenonsense fmuchof 17thcenturycience, f the entire ffort f thecorpuscularphilosophyo explain heperceived ropertiesf things ymeansof causes hem-selvesnot directlywarrantedn perception. nsofar s Humecould have hadanyscience n mind, t couldonlyhavebeenmechanics,nd evenmechanicsnlywith-out theconcept f forcewhichhad originallyeen thekeyof its success. In thenew sciences,awlikenesss notan explainer,t is whathas to be explained. TheobservedonjunctionfanA-type ith B-typemayhelpus toexplain Bwhenwefind nebysuggestinghat twascausedbyan A. Butthis s only preliminaryoscience. Whatwe willultimately ant to know s whatunderlyingtructure,tselfnot observed,s responsibleortheco-occurrencefA's and B's inthe first lace.In a P-sciencef the ancientor indeed f theHumean) ort,tis difficulto knowwhyanyhypothesis hich"'saves he phenomena"hould verbe regardeds adhoc.64 In thenewer mpler otion fT-science,t is theunderlyingausal tructurewhich elps odiscriminateetween heproperlyxplanatorynd the dhoc.Thus,when saythat hegoalofT-sciencesa knowledgefcauses, do notmean'cause'to be taken s Humetook t. Or f were osaythatT-scienceims ttheore-ticalexplanation,wouldnotwant theoretical'o be construeds deductive-nomo-logical', o umpto themodern ersion f the Humean octrine.What swrong iththatdoctrines that t does not do justice o therichnessf theoreticalcience,venthe science f Hume'sownday, etalone the mmenselyomplex tructuralciences



17/29

52 APAPROCEEDINGSthatbegan otake hape n the 19th entury.65

5. Somemorals fthis toryAndnowit is time o draw omemorals rom his ongtale,morals hatbearonmytopic: "The goalsof natural cience". But before do, a fewnecessarylarifi-cations irst.When speakof thegoalsofscience, amthinkingrimarilyfscienceas an activityn thepart f a skilledommunity,otof ciencen tsother,ommon-er,senseas a bodyofpropositionsetdown n a textbook rresearchrticle.AndI amtakingheterm,goal', n both of themain enses f that lipperyerm.Therearethe dealgoals also calledexplicit racknowledged),hegoalsthat cientistsx-presslypecifys the aimsoftheirwork. Andthen here rethe ctualgoalswhichareembodiedn theactivitytself,omewhats a teloswasthoughtyAristotleobeembodiednallnaturalmotion.The dealgoals anbediscoveredromwhat cientistssay,though here an be considerableisagreementithinhecommunityfscien-tistsnregardo them. To learn heactualgoals, ne must crutinizehat cientistsdo, and try o determinerom hestructureftheactivitytselfwhatwouldcountas "success" n it,as I tried o do withBabylonianstronomy. here s roomfordisagreementegardinghe actualgoalsof a particularnstance fscientificctivityalso,mainly ecausedifferentnterpretersill stimateuccess ifferently.A strikingeature f Greek sciencewas thedivergenceetween he ideal goals(as enunciatedn thePosterior nalytics,orexample) nd the actualgoalsofthe

enterpriseo far s we can reconstructt historically. ut thatsortof divergenceis not peculiar o Greek cience. One findst again n thework, ay,ofDescartesor Newton. Eventoday,we tendto distrusthepronouncementsfmajor cien-tistson themethods nd goalsof science, distrust"n the sensethattheir eflec-tionsdo notalwaysdo justice so far s one cantell)to what s actually oing n ntheir aboratoryr study. Einstein's phorismboutwatching hatscientistsoratherhan isteningo whatthey ay,comesto mind, nd s particularlypposite,it happens,n regardo Einstein imself.Historiansaveto take nto ccountbothsorts f goals, ndweavethem ogethern one wayor anothernmakingenseofdeepchangesnpast cience.Andnow, t ast, or hemorals fmy tory.Moral 1: The goals of sciencehave changed undamentallyverthecenturies.What eadsme to speakof change, atherhandiscontinuityr simplepluralism,is the underlyingontinuityrovided y communitiesf scholarsnd researchers,formed y the samebooks,taught y thesamemethods,n active ommunicationacross paceandtime. When saythat hegoals f science ave hanged,mean hattherehas beena gradual volutionn method ndexpectationrom negenerationto thenext,or sometimes ithin he samegeneration.Whatpermitsme to speakof science cross ll of thesechanges f theyears, espite hewide differencese-tween heaimsof theBabylonianstronomernd thoseof the Florentinehysicist,is that heres a livingontinuousink cross hecenturies,s thecommunalctivityof inquiryntonature s graduallyransformed.o direct he sameterm,science',to allofthisdiversitysnottorenderhe ermquivocal.I can rememberhatwhenMarshall lagett'sTheScienceof Mechanicsn theMiddleAges appeared n 1959, thetitlegavegreat ffenceo some. Onediscipleof Reichenbach'strenuouslybjected oanyuseof thetermscience' or nything



18/29

PRESIDENTIAL ADDRESS -MC MULLIN 53that went on beforeGalileo'sday. EvenPopper, o perceptive critic f logicalpositivismn otherregards,oo often eems o haveassumed hatthe method fconjecturend refutation,n invariantationalityenteredn modustollens,wasfirstormulatedn the17th entury,ndthatwitht science egan.This sortof ahistoricalpproachwaseffectivelyhallenged yKuhn ndFeyera-bend. (Recall Feyerabend'sivid hapter-heading:Aristotle ota dead dog".)66Others incethenhaveextended heir rgument. nce onechallengeshepositivistpresuppositionhat heres a unique cientific ethod avinghe effectiveormfalogic, tbecomesmuchessplausibleoassume,s thepositivistslmostnvariablyid,that ciencebegan,more r essabruptly,uringhe ifetimesfBacon andGalileo.Moral2: Whatbroughtboutthechanges fgoalwerefor hemostpart easonsinternalo theactivitytself. One adoptsa goal only f it appears esirable.Onemodifiest if it provesnot to be achievables itstands. Onemaynot know hatcertain ctivitys desirable. It didnotoccur, pparently,o peoplesof theearlyfirstmillennium.C. other hahtheBabylonians,hat twouldbe desirable, ithinthe broadpattern fhumannterests,o constructxact unar nd solarcalendarsbasedon a continuously-keptecord.But once theactivity egins,nd given hesocialand economic onditionshatpermittscontinuance--arucialproviso--whatillmainly endto modifyt (so itwouldseem)willbe discoveries adebythepractitionershemselves. orexample,it maygraduallye realized hatthe dealgoalsthathavebeenpropoundedre nfactnotachievables they tand. This swhathappenedwithD-sciencenthe 17thcentury.The transition asvery low; t was nothingikea gestaltwitchwhen tcame. One finds cientistsf thedaylivingn bothworlds, s itwere:effectivelyconstructinglements f a T-scienceas Galileo did infields ther hanmechanics)yetspeakings though emonstrationfthe old sort ould till eattained.67 omeattemptedheold ideal ofscience nonearea,usuallymechanics, hile bandoningit in others. Kant's workprovides erhaps hemost trikingxample f this ortof dividedmind. In theMetaphysicaloundations fNatural cience,he came asclose to a D-science f mechanicss anyonehas everdone,whilerelegatinguchfieldss chemistryothe owly mpiricaltatus fa P-science.Or thegoalsmaybe modified y extendinghem n waysthat eemprofitable.Ptolemy ealized hatthe predictiveoalof Babyloniancience ouldbe achievedin a differentayifastronomersouldestablishontinuousrbits or heheavenlybodiesandnot ustprivilegedoints ikerisingsnd settings. his llowed heuseofmore owerfuleometrical ethods,eplacinghe imitedndunexplainedrithme-tical computationevices f hispredecessors. utthisbeganto shift hesciencein an explanatory,ndultimatelytheoretical,irectionince heorbits retheore-tical entities,nd questionsmmediatelyose themselvesboutthereality f thepaths ttributed,s wellas abouttheagenciesnvolvednmakingheplanets ollowthepaths, uestions hat imply ever rosewithinhesimpler erspectivefBaby-lonia. Again,nstrumentsikethetelescope ndthemicroscopemaybe discoveredwhich penup a wholenewrealm f inquiry,n inquiry hich annot erhaps ecarried n in thetraditional ay. Newor modified oalsthen mpose hemselvesifthe nquirys tohave nacceptableutcome.Whatmakes his econdmoral imelys thetendencyn thepart frecent heo-rists f science68 o argue hat hegoalsofscience,ikethetheoriesfscience, reshapedby (and ultimatelyxplainablen terms f) cultural nd economic actors



19/29

54 APAPROCEEDINGSexternal o science nderstoodnthetraditionalognitivistense. That uchfactorsare importantn thiscontext annotbe gainsaid.Wehave eenthat heoriginsfpredictivestronomyie deep nBabylonianeligiouseliefs.TheBabylonians erenot originallynterestedn predictionutonly nthecorrelatingfcertain elestialeventswithsignificantappeningsn earth. Likewise, he nitial ttitude owardstraditional eliefs n medicine nd religiono importantn thegenesis f naturalscience n Ionia maywellhave beenconditionedy political nd socialfeaturesftheGreek ity-state. ndthesearch or ternalndnecessaryruth hat nfluencedthe formationfthe dealofD-sciencemaywellhavebeenpartly eligiousnorigin.But all thishaving eensaid, t is importanto recognizehatchangesn thesegoals,once the goals themselvesame to be articulatedn a successfulommunalpractice,eemto havebeenmuchmore ueto factorsnternalothat ractice.Thereis no evidence hat heformationftheT-idealnthe 17th enturywed nythingnitscontent o cultural actors. say"in itscontent" ecause t is triviallyrue hatthe practice f science, hen s now,depended n the socio-economicase of thesociety, s well as on the traditionsf earningn that ociety.Itwasno accident,one supposes,hat he North talian ity-statesurnishedfertileround or cienti-ficactivityuringhe ateRenaissance.But this n noway mplies hat hecontentof scienceor thearticulationf itsgoalsderivedngeneraln some differentialayfrom ne sort fculturalackgroundatherhan rom nother.Wemaywant osay--indeedwe must ay--thatheactivityf scientistss causally elatedn all sorts fwaysto broader sychologicalnd socialregularities. utthis s not to hold thatchanges n thegoalsof thatactivity--Descartes'doption f hypothetical ethods,for xample--cane explained yrecourseo facts bout French ulturen theearly17th entury.Moral3: Thegoal of technical ontrol layedvirtuallyo part ntheoriginsfscience. It is usualto point o thesocialseparationetweenrtisan ndfull itizenin the ancientGreekworld, nd to the craftmysteries hich xcluded utsidersfrom he secrets f thehigh echnologicalkills lready oundnot only n Greecebut in at least as developed state n manyotherparts f theancientworld. Butthematterunsdeeper han his. The Greek -science idnotdepend or tswarrantuponthetestof consequences.Andthegapbetweennatural cience, s Aristotleconceived t, and actual technologicalontrolwas so great hattheidea thatonemight ctually nformhe other implywouldnot haveoccurredo anyone. Ofcourse, herewerepeople ike ArchimedesndHeroof Alexandria hose nspirationwas notAristotelian. utin general,he structuref D-sciencewas suchthatthesuppositionhat ts goalsought omehow nclude ontrol fNature,f it weretomake genuine laim oanunderstandingfNature, suppositionhat eems ntirelyplausibleous,wasblocked ightrom hebeginning.There s a tendencyometimesmong raxis-orientedontemporaryritersodis-missGreeksciencebecauseof its being, s they ay, "contemplative"n itsgoal.Thisterm aneasilymislead, owever. t is true hat he dealof theoria asknowl-edgeforthe sakeofknowledge,orthepure pleasure f understanding. ristotleargued at times, t least) thatunderstandingf thiskind constitutedhehighesthuman oal, hegoalthat etman losest otheDivine.But the furthermplicationometimesgiven the term hat cience tselfwasthought f as an armchairtudy, s somethingo be pursued rimarilyy inwardreflection,s of coursefalse. Aristotlewasnothingf notan empirically-inclined



20/29

PRESIDENTIALADDRESS - MCMULLIN 55researcher,hether e was dealingwithmarine rganismsrwithpolitical onstitu-tions. D-sciencewassupposedobegin rom remissesnchoredy n ntuitiverasp,an epagoge, f theconceptsnvolved.ButAristotle ade t quiteclear, oth nhisdiscussions f methodndinhis ownpractice,hat uch grasp idnotcomeeasy,that t often equired longexperience ith hematternvolved.Wemightriticizehimtodayforhisfailureo test omeof theclaimshemadeaboutspecific atures.But we can onlymarvel t thebreadth nd intensityf his ifelongnvolvementnthemostminute etails f thenaturalrder.If thegoaloftechnicalontrol layed eryittle irect ole n theoriginsfscience,whatabout the emphasis iven t by such writerss Bacon n the 17thcentury?"Thetrue nd awful oalofthesciences s noneother han his:thathumanifebeendowedwithnewdiscoveriesndpowers".69Herewe have obecareful. t struethatBacon hailedthepromise fthenewsort fknowlegeor he mprovementfthehuman ondition,orundoinginhisview)thedamage oneto manbytheFall.It is also truethatone ofhis strongestriticismsf the oldernatural hilosophywas of its inabilityo produce nytangible ruitsn thetechnical rder. Butheemphasizesmore hanonce ntheNewOrganonhat n theorder fthenew cience,understandingust omefirst.Instead fprematurelyeekingexperimentsffruit",nemust:

imitate hedivine rocedure hichn tsfirstay'swork reatedight nlyandassignedo it oneentire ay, nwhich ay tproduced omaterialwork utproceededothat nthedays ollowing.70Bacon believes hattheprocess f inquirymaybe distortedftoo muchemphasisis given oo soonto matters f practicalpplication.Technical ontrol s to be aconsequence,nd in thatsensea touchstone,f the newscience ather han goalin tsownright.Furthermore,n a centuryo concernedwith the phenomena evealedby thetelescope,t wouldhardly aveoccurredo anyone o makecontrol general oalof science,n thesense n which his s oftendonetoday. The phrasepredictionand control' s dotted hroughouthepagesofneo-MarxistheoristsikeHabermas

orsociologistsfscience ikeBarnes,s thoughomehowhe wo lways otogether.Butscientistsf Galileo'sgeneration,oth n wordandpractice,made t clear hatastrophysicsas wehavecome ocall t)aims olely tanunderstandingfthepheno-menaofcomets rsunspotsrnovae. Inno sensewas tpursued ecauseofa hopeoftechnologicaldvantage.Itwouldonlybe in the19th enturyhat henew ciences or hefirstime eganto fulfillhepromise hatBacon had heldoutfor hem fguidingndacceleratingtechnologicalhange. tprovedobea faronger oadfromheoreticalnderstandingto thedetails fthematerial rocesseshat ffect umanife hanBaconorDescartesor theFrench ncyclopedistsadassumed twouldbe. In a real ense,thad to bediscoveredhat t waspossible.Thoughogicmightuggesthat science ested yits consequences ughtto revolutionize technologyuiltsolelyon craft kills,therewas nothing priori bout thathappeningn thisparticularossibleworld.Moral4: Scientificationalitys discoveredntheprocess fattemptingorealizethegoalsof science. It has becomecustomaryodayto distinguishetween logi-cality"and "rationality",etween heformal rocesses f deductiveogicand the



21/29

56 APAPROCEEDINGSmuchbroader epertoirefcognitiverocedureshat hescientistequires.Rationa-lity nvolves heassessmentfthevalidityndsignificancefexperimentalvidence;it extends o suchrequirementss reproducibilitynd to suchtechniauess idealiza-tion. Above ll, t requiresheskills ftheory-appraisal,killsmore kinto thedis-cerningf a valuethan o theapplicationfa rule.71 Bynow, suppose,twouldbe generallydmittedhatthecriterian terms fwhich theorys assessed,uchcriteria s predictiveccuracy, oherence,onsistency,ertility,implicity,o notfunction s an algorithm,s a setofrules f nference. his swhat llows wosetsof scientistsooking t thesameevidence--andmean hesameevidence--toupporttwodifferentheoriess thebest heorieselativeo that vidence.Now all of thiswas alreadybecomingvidentn the 17thcentury.Onceonemovesfrom he demonstrationsf D-science r themathematicalredictionsfP-science o theassessmentfhypothesisharacteristicf T-science, newapproachto evidences needed. Indeed, omethingf thishad beengraspedongbeforenthediscussionsf ex suppositioneeasoning uringhemedieval eriod nd intherichtraditionf analysis nd synthesisoing ackto Aristotle imself.But twasonlywhenhypothesisecametheacceptedmethod fworkingcientistshatonebegins o finddetaileddiscussionsf thecriterionfsimplicityr of theweightobe given o fertility,or nstance.Onefinds hemnBacon, nDescartes,boveallperhapsnKepler,who n theApologiaTychonisrovidederhapshemost laborateaccount of hypothesis-assessmentivenby any workingcientistp to thattime,an accountwhich eriveslmost ntirelyrom isownpractice.72

Therehas beenmuchdiscussionn recentyears s to whetherherationalityfsciencechanges vertime, nd if so, what thisdoes to traditionallaimsfortheobjectivityf science. In The Structuref Scientific evolutions, uhnarguedthatthe choicebetween ompeting aradigmscannotbe determined erely ytheevaluativeroceduresharacteristicfnormalcience, or hesedependnpartupona particulararadigm,nd thatparadigms at issue".73 The mplicationf this s,of course, hatthe evaluative roceduresf science hangewhenparadigmshange.In a laterpaper,however, e saysthat"the valuesdeployedn theory-choicerefixed nceand for ll,unaffectedytheir articipationn transitionsromnetheoryto another".74He allows hat mallvariations ayoccur, utthen oesontomakea strikingomment:

Thoughheexperiencef scientistsrovidesophilosophicalustifi-cation or hevalues hey eploysuchustificationould olve heproblemf nduction),hose alues re npartearned rom hat x-periencendthey volvewitht.This commentnablesme to situatemyownpositionn regardo thesevaluesas well as to thebroader ationalityfwhichhey rethekey lement.This ational-ity s learnedby theexperiencef scientists,s Kuhnsays, nd as I have tried oillustrateere n detail. Furthermore,he evaluativeroceduresidchangemarkedlyas thecommunityf scientistsmoved rom -scienceo T-science,nd ater, s thenewprocedures eredebated nd tested utthroughouthe 18th nd 19th enturies.The values nvolvedn theory-appraisalnd therationalityf which heyforma partare in the end instrumentalalues,means o theends science n generalsexpected o realize. They renot ends n themselves. hey an be ustifiednlyby



22/29

PRESIDENTIAL ADDRESS -MCMULLIN 57theextent o which hey urtherhegoalsthat ciences taken o aimat. Andthejustificationere s in the firstnstance f a practicalort, s scientistsraduallylearnhowbestto understandhese pistemicalues,whatrelative eightso attachto them, ndperhapswhatother aluesmightlso serve s a means o furtherhesegoalsmore ffectively.Does makingationalityelativenthiswayto thegoalsofscience oncede othesceptical hallengefthesocialconstructionistsr ofFeyerabend? think ot. Thegoalsof sciencehavedeveloped,s we haveseen, n a progressivendreason-givingway. Theyembody asichumannterests;hechanges,s wehave een,havecomemainly rom herealizationhatthegoalswouldhaveto be modifiedn order hatsomethingike theoriginal oals might tillbe achieved. The crucialpoint s thatwe can tellwhen dealgoals rebeing chieved r when ctualgoals rebeingmoreeffectivelyeached han before. The goalsof theoreticalciencehave been moreand more uccessfullyeached,n their wnterms,rom he 17thcenturynwards.This s thesort fwarrantnwhich herationalityfscience estsnthefirstlace.But t snot tsonlywarrant. nd hat ringsmeto:Moral5: The rationalityf science an be philosophicallyustified.Here dis-agreewithKuhn. What hilosophersfsciencehave abored o longto show s thatsuchvalues s fertilityre an appropriateriterionftheory.Their rgumentsre na broad sense ogicalor epistemological.Whewellmorethana centurygo,madean elaborate heoreticalase for he"consilience finductions"s a desideratumnevaluatingheoryt least s importants empiricalccuracy.What appensnphilo-sophyof sciencereflectst the second evelwhathappensn science tself. Thatis, it is empiricallyiscoveredn scientificractice hat certain indsof evaluativeproceduresr ofepistemicemandslikethereproducibilityfexperimentalesults)are effectiven bringingbout thebroadly-statedoalsof science. Then a theoryof a philosophicalort s constructedo accountforthis. If thetheorys a goodone-and thisraisesfurtherssues--iterves s an indirect nd tentativeustificationofthepracticetself.In the end, then,historicismnd logicismmaystillconverge.Wemaystillbeable to construct philosophyf science hatderives othfrom he earninghathasgone n nhistorynd from more eneralogical ndepistemologicalramework.Logic or epistemologyf themselves ould neverhavehad theresourceso comeup withanythingike thecomplex nd pluralisticcientific ethodologyhathascharacterizedhe natural ciences n recent enturies. On the otherhand,thatmethodologys not just a contingentmpiricalact; t can be "explained"n theratherpecial ense nwhich hilosophicalheoryonstitutesn explanation.Therehas been,of course,muchdisagreements to whatthe besttheorys here, dis-agreementhathas beenparticularly arked n the ast two decades. Buteven hepossibilityf a good theory erewould uggesthatphilosophyfscience antakeon a normativeoleas it surveyshediversityfhistoricalndcontemporarycienti-ficpractice. needhardlyayhowfragile balance hismakesbetween hehistori-cal andthe ogical, hedescriptivendthenormative.Butonemoral ooneexpectsme to draw, hope, s thatphilosophyf science ught o offer imple olutionsYou willhavenoted hat didnotcarryhehistoricaltorymuchbeyond1700.Were to extend t as far s thepresent ay, heprincipalevelopmentwouldwantto grapplewith s thegrowthf questioningn our owncentury,rom ources nphilosophy,nhistoryfscience,nd fromwithinciencetself,nregardo theoreti-



23/29

58 APAPROCEEDINGScal entities. The outcome f suchquestioningouldbe a substantial odificationin thegoalsof T-science, dilution f itstheoreticalomponentor omeparts fscience, ikequantummechanics,t least. In itsmostradical orms,s for xamplein classical nstrumentalismr in theconstructivempiricismecentlyroposed yvanFraassen, he distrustf theoreticalnderstandingould eadus backto some-thing eryike heminimaloals fP-science.There s no wayto handle hese ssueswithoutooking t both thepractice fcontemporarycienceand the objectionsbrought gainst ealism rom o manydifferentuarters. n his mostrecentwork,Realism nd theAimofScience,KarlPopperhas thisto say: "The taskofscience,whichs to find atisfactory,xplana-tions, anhardly e understoodf we arenotrealists"75Critics f scientificealismhave perceivedhis inkquite clearly,ndhaveargued ither hatexplanation,oconstrued,s not in tact a proper oal of science, relse that t doesnot furnishsufficient arrant orrealism.Thedebatehasbeen an unsatisfactoryne,not eastbecausethe term,realism', as proven lmost nfinitelylastic. It is striking,orexample, o find o manyof those whobeginby announcinghatrealisms deadendingwith n "acceptable" ersionf the upposedlyefunctoctrine...I realize hehazards fdrawingmorals rom istory,s I havebeendoing,nd thelikelihood f findinghere hemorals ne is predisposedo expect. But ntheend,I see no betterwayto proceed. Thegoalsofanycomplexhuman ctivityre bestgraspedy recreating,s faithfullys onecan,howthat ctivityas taken hape.

FOOTNOTES1Proceedings nd Addresses of theAmericanPhilosophicalAssociation,45, 1971-72, 5-21.20p. cit., p. 5.3"Scientificastronomy n antiquity", n The Place of Astronomy n theAncientWorld, d.F.R. Hodson,Oxford:OxfordUniversityress, 974,21-42;seepp.41-2. (This lsoappearedas Phil. Trans.Royal SocietyLondonA, 276, 1974).4Magic, eason, ndExperience,ambridge:ambridgeniversityress, 979,p. 264.5See A. Leo Oppenheim,AncientMesopotamia: Portraitof a Dead Civilization,Chicago;UniversityfChicago ress,evisedyE. Reiner, 977,pp.207-8.6"Babylonianmen extsmakemanifesthe beliefn a schematicrder f all phenomena;thatnsightnto hefutureourse fevents ouldbe obtainedeflectsnassumptionhat ventswereprearrangedn accordance ith ome nterpretableesign,newhich everthelessas sus-ceptible o theforces fmagic. The course f eventswastherebyonsideredeitherausallyconnected ith hesignshat ortendedhem, or nevitableonsequenceshereof". rancescaRochberg-Halton,Fate anddivinationnMesopotamia",rchivurOrientforschung,9, 1982,363-371; ee p. 368. I am indebtedo Dr.Rochberg-Haltonor eferenceso literaturen theearly abylonianmen-lists,s wellfor urdiscussionsf the ignificancef theseists.7'EnumaAnuEnlil'arethe pening ords: Whenthegods)Anu ndEnlilmade heheavensandtheearth)".TheauthorityftheEnumaAnu Enlilwouldbe closer o that f a legal rece-dent han o that fa canonic ext fScripture.ee W.W. allo, Newviewpointsncuneiformliterature",sraelExplorationJournal, 2, 1962, 21-25.



24/29

PRESIDENTIAL ADDRESS -MC MULLIN 598Thousandsf tablets rom hereignsf theAssyrianmperorssarhaddon680-669) ndAssurbanipal668-627)show hat n the eventhenturyreportsn astral menas,nthefirstsightingf themoon, n itsoppositiono the un, neclipsesnd onseismic,tmosphericnd

other eeminglyntowardvents, erewrittenotonly nthecapital ftheempireNineveh],but lso n allthe mportantities ftherealm".These eportsxhibituch imilaritiesfcontent,wording,ndphysicalhape, that heymust e takenoreflectheworkingsfa well-establishedinstitution. statewide etworkfobservationtationsharged ith ispatchinguch eportstothecapitalwasquite ikelynexistence",. LeoOppenheim,Divinationndcelestialbserva-tion n the astAssyrianmpire", entaurus,4, 1969,97-135;seep. 114. The functionfeachreportwas to inform heruler f a notable henomenon,elestialratmospheric,ndofits"ominous" ignificance.hefocuss still ntheomen-characterf the stronomicalbserva-tions. In thesamecentury,owever,diaries" rsystematicecords f theobservationshem-selves,make heir irstppearance. hey pan heperiod . 650 B.C.-50 B.C., hebulk fthemcoming romfter 00 B.C. See A. Sachs, Babylonianbservationalstronomy",n ThePlaceofAstronomyntheAncientWorld,p.43-50. In theAlmagestIII, 7; p. 103),Ptolemy akesa famouseferenceohisuse ofBabylonianclipse ecords hat oback o the eignfNabonas-sar 747-734):"we haveancient bservationsompletelyreservedromhat eriod o thepre-sent".Records soldas this avenotbeenfoundsyet.

9See Oppenheim,Divinationnd celestial bservation". uring he ater eleucidperioda number fwritersf ephemeridesredescribedshaving scribe f theomen eries,numa-Anu-Enlil,s their ncestor.See O. Neugebauer,he ExactSciencesnAntiquity,ewYork:Dover, 969,p. 136.100ne oftheoddest eaturesfthis torysthatBabylonian athematicsttainedtsheightin thevery arliest eriod fwhichwe have ecords1800-1600B.C.);nofurtherevelopmentoccurredntil heSeleucid ra 300 B.C. - 50 B.C.),when heneeds fthenewmathematical

astronomy ayhavefurnishedhe ncentive or uch mprovementss the ntroductionfthezero. Babylonianmathematicsemainedntirelyrithmeticaln approach; roblemsregardingareas, or xample) hatwewouldregards geometricalere olvednumerically.woclassesoftablets refound. In one,a problems formulatedndthe method fsolutions carefullyspecified,tepbystep; ntheother, listofproblemssgiven, suallyrrangednorder fdiffi-culty.The testn each case s tofind number hich atisfiesertainonditions,hethertbetheconditionsf an inheritance,f a division f land,or ofanassignmentfwages.A quasi-algebraicechniquellowed, quivalently,he olutionfquadraticquations or wounknowns.A generalizedlgebraicymbolismas never eveloped.Thoughheproblem-typeserepracti-cal in origin,t seems lear hat hetechniquesadbecome nend nthemselvesor he cribalgroup pecializingnmathematicalroblem-solving.eugebauerotes hat heproblemsften"disregardedeality"."It is a lucky ccidentftheunknown umber fworkmen,ound ysolving quadratic quation,s an integer.Obviously,healgebraicelations theonlypointof nterest",p.cit., .42.11Twodifferentystems ereusedfor unar ppearances,nvolvingheequivalentf a step-functionSystemA, as it hascometobe called) nonecase, nda zig-zagunctionSystem )in the other. System isolder; ystem is somewhat ore ccurate.But both ystems ereretainedhroughouthe ntire eriod250-50B.C.) during hich phemeridesere onstructed.Forplanetaryalculations,nevengreateriversityfnumericalpproximationethodsppearsto havebeen imultaneouslynuse. Neugebauerotes hat uchpurelymathematicalonsidera-tions s easeofcalculation ouldseemtohavebeen major riterionop. cit.,p. 115). Sincethenumericalechniques ere ot inked oanygeneralheoryurportingoexplain hemotions,therewouldhavebeenno suggestionhat ne ofthemwas"right"ndtheothers rong.Theirfunction assimplyopredict.Even houghhe ctual unarnd olarmotions ould ave eenverydifferentnder ystems andB, bothsystemsould be retained,erhaps ecause herewasnota clear nough redictivedvantageor ystem ,perhaps ecause ystem was some-what asier o use,perhaps ecause heremayhavebeendifferingchool raditions. hemainpoints that hesewerenottheoreticalifferencesnthemodernense, nlydifferencesncom-putationalechnique here greateriversityightetolerated.



25/29

60 APA PROCEEDINGS12Aaboe peaks f the "theoriesnderlyingheprocedures"ollowednBabylonianstrono-my, nd callstheephemerideshemselvestheoreticalchemes"op. cit,pp. 30, 35). Herightlywantsto emphasizehat theBabyloniansnderstoodhe mathematicalechniquesheywere

using.Another roceduresedby themwas to notewhen planet repeatedtself'. Jupiter,for xample, epeatstselfvery 1 years;what t did 71 years go, t willdo again hisyear nthe amedates. So therecord ftheearlier ear anbe usedtopredict. utthis, aboe rgues,is likethetechniquesed nmodern eather-forecasting;t s "pre-scientific"ecausetdoesnotgiveus "control ver he rregularitiesithin achperiod", nd so observationalecordsmuststillbe constantlyhecked. A properlyscientificstronomicalheory"s "a mathematicaldescriptionf celestial henomenaapableofyieldingumericalredictionshat anbe testedagainstbservations"op cit.,p. 23). In ourusage, his s nota sufficientriterionor heoryna naturalcience uch sastronomy.ut t ssufficientor -science.13Lloyd,p. cit., p.265,266.14Lloyd,p. cit., . 52.15Fragment.16QuotednLloyd, p.cit., . 16.170p.cit., . 21.180nAncient edicine,hap.19,quoted nLloyd, p.cit., . 54.19Physics,I, 7; 198a 22.201nAristotelise CoeloCommentaria,erlin: . Heibergd.,1894,253a 37-253b ; 248b40-285a 1. There s somedoubt s towhetherlatoreallywouldhave llowed hat hepheno-mena ouldbe saved y anymathematicalormalism.hephrasesavinghephenomena',ftenidentifiedith hePlatonic radition,s not found efore osigenes, philosopherf the econdcentury .D. Simpliciusses tvery requently,s a glance t the ubjectndexntheHeibergeditionwill how. D.R. Dicks amentshe mbiguityfthephrasewhich,nhisview, has edto themisleadingdea that heGreek stronomersere oncernedmainlywithdistortingheresults f observationo makethemfit ntopreconceivedheoreticalchemes"EarlyGreekAstronomyoAristotle,ondon:Thames ndHudson, 970,p. 258). In hisbook, ozeintaPhainomenaTo Save theAppearances,ranslatedyE. Doland ndC. Maschler,hicago:Uni-versityfChicago ress, 969)Pierre uhem akes heoppositeandcommoner)iew hat av-ingthephenomena eant ittingmathematicalormalismothem,ndependentlyfanycon-

cernwithheoreticalnterpretation.21528E -530C.22PaulShorey ranslation,nPlato: The Collected ialogues,d.E. Hamiltonnd H. Cairns,NewYork:Pantheon,961,529b. Translationlightly odified.23529d.24Gregorylastos,TheroleofobservationnPlato's onceptionfastronomy",n J.Anton(ed.),Science ndthe ciencesnPlato,NewYork:Eidos,1981,pp.1-30; eep. 15.25530B. I follow lastos' ranslationop.cit., . 3) in this nstance.26Physics,I, 2; 194a6.27It is extremelyifficulto reconcilehe differentextsn theMetaphysics,hePosteriorAnalyticsndthePhysicswhere e treats his uestion, ut the ssue s too large o dealwithhere.



26/29

PRESIDENTIALADDRESS -MC MULLIN 6128193b25-30.29The undoesnot deviate rom heeclipticas themoondoes), nd tsmotion nthe clip-

tic snon-uniformwhich everalfEudoxus'predecessorsadalready oted); udoxus swrongonboth hese cores.30Planetst times emain tationarygainsthebackgroundfthefixed tars, henmovebackwardswestwards)or certainime eforeesumingheir ormaleastwards) otion.31Ina famous aper,G.V.Schiaparellihowed owEudoxus' oncentric odel ouldbemadefairlyccuratelyredictiveexcept or heretrogradeotionsfMars ndVenuswhich,nprin-ciple, hismodel annot xplain; eeAaboe,op. cit.,p. 39). Butas Dicks op. cit.chapter)convincinglyemonstrates,his s as much tribute o Schiaparelli'sntenuitys to themeritsof theEudoxan ystem.Ourknowledgefthis ystemomes ntirelyrom eferencesnotherancientwriters,inceall Eudoxus'ownworks re lost. Schiaparelliostulates,or xample,

thatour two main ources, ristotlendSimplicius,otEudoxusquitewrongnregardotherelative olesofthesecond ndthird unar pheres.Thisenableshimto setup a muchmoresuccessfulccount. He also assumes n observationalnowledgef theretrogradeotions ftheplanets hatEudoxus s mostunlikelyo havepossessed.Dicksargues hatwhatmoderncommentators,ikeSchiaparellindDreyer,rereallyhowingre thepotentialitiesfa modelof the Eudoxan ype, rovidedhatonehasa fairlyxactknowledgefplanetary otions ndof phericaleometry.ut hese ame nlymuchater.32J.L.E.Dreyer rgues hat"as Eudoxusmadeno attempto connect hemovementsfthevarious roups f sphereswitheachother,t seems robable hathe onlyregardedhemasgeometricalonstructionsuitable or omputinghe pparentaths ftheplanets"AHistoryofAstronomy,evised y W.H.Stahl,NewYork:Dover,1953,originaldition 906,p. 91).

Thisseems weakargument,othbecausewe havenothingt allfrom udoxus n this ointandbecause herewas no reasonwhy achplanetmight ot havebeenassigned dynamicallyindependentystem.Dicks ikewiseakes udoxus' pheresohavebeen"mathematicalbstrac-tions", n thegroundshathe didnot peculatenthematerialfwhich heywere omposedor theconnectionsetween hem r thepowers hatmoved hemop. cit.,p. 257). Butfirst,weonlyhave fewfragmentsfhiswork,ndsecond, lack fspeculationn theseatterssuesby no means ntails hathe regardedhespheress calculatingevices. Dickshimselfointsout howthepolesof one spherere"attached" o thenext uter ne n such waythat t s"carriedound" y t. This sa highly hysicalonception.33Who dded even phereso the26 ofEudoxus, woeachfor un ndmoon, ndoneeachforMercury, enus and Mars. Schiaparellihowshowthe extraplanetaryphere ouldhave

enabled heEudoxanmodelto handle heproblemfretrograde otion, he twospheresorthe uncouldhave olved heproblemf tsvariablepparent otionnthe cliptic. inceCallip-pus'works ost,wecanonly uess thisreasons.34MetaphysicsII,8; 1073b37-1074a6.35Dicks ssumes hat each spheres immediatelyollowed y itscounteractingphere,nwhich ase,ofcourse,achmotionwill mmediatelyancel ut and theplanet nthe ast pherewillnothave hedesiredmotions;or his eason, icksconcludeshat he ystemoesnotwork(op. cit.,p. 203). Dreyer,n theotherhand, uggestshat hecounteractingpheresor achplanet ome, s a group, elow heplanetndthus fter herequiredmotions ave lreadyeenimpartedo it op. cit.,pp. 112-3). This ystem ould epredictivelyquivalentotheEudoxan

one; each planet'smotionwould tillbe computedn thebasisofitsownclusterf spheresonly withouthecounteractingpheres).But the ystem ouldbe enormously ore umbrousinmechanicalerms.



27/29

62 APAPROCEEDINGS36The motion f one sphere annot xplain, ince t does notdetermine,hemotion fthesphere extbelow t. (Recallthat he twoaxesdo notcoincide,nd the peed fthe econdrotationsquite ndependentfthat fthefirst).The Eudoxan ystem asmeant oshow hat

ifonehad a setoffour pheres,nterlockingndrotatingntheway pecified,he esultantom-bination fthefour ircular otionsouldexplain he pparentlyrregularotion f theplanetattachedo the owest phere.WhenwritinghePhysicsndtheDe Caelo,Aristotle ayhavebeentemptedo infer rom his hat hemotion f the firstphere aused that ftheothers.Confusionetween he downwardausalityf D-science ndthepostulationalpward xplana-tion fastronomyas oaccompanyristoteliancienceighto the nd.37XII,chaptersand8.38The UnmovedMover roper o eachspherewouldbe responsibleteleologically)orthesimple ircularmotion fthat phere.Then achsphere ouldbe (mechanically)arriedytheone above t andcarry heonebelow t,thus haringhe motion ftheformerndpassingt

(with ts ownmotion lso)to the one below t. Thiscouldwork,f thetwotypes f ctionde-sire, nd contact ctionbetween pheres) e conceded. Manycommentatorsavesuggestedthat he nelegant ultiplicityf the55 UnmovedMovers anbebroughtnder he gency fa single irstMoverfthe attersmade heobject fdesire n thepart ftheformer.utDicksis, think,ighto argue hat hishasnobasis nthetextop.cit., . 214),even hought wouldbringbout he ort fexplanatorynificationhatAristotlesuallyoughtor.39This s Dicks'renderingf 1074a 5 (op. cit.,p. 200). Rosssays:"only hus anall theforces t workproduce he observedmotion f theplanets".The term forces' eregives noverlymechanicalenderingf mode factionwhich heprevioushapteras ssertedooperate(at east,npart) ydesire.40MetaphysicsII,8; 1074a16.411074a 31. One canseehere heroots f anastrologyuitedifferentnitsbasisfrom heomen-listsftheBabylonians.420ne other ttempto unite hem uringhatperiod ught e noted.Heracleides,con-temporaryfAristotle's,roposed geocentric odel nwhich he earthwasgiven hesinglemovementfrotation,hus liminatingheneedfor fast-movingpherefthefixed tarsndof theconsequentdjustmentseededfortheplanetarymotions. In thefollowingentury,Aristarchusaccordingo Simplicius) roposed s an "hypothesis"hefullheliocentric odel,in which unand stars reatrest,nd theearth as a doublemovementfrotationndrevolu-tion. (See T.L. Heath,AristarchusfSamos,Oxford, 913). Dreyernfershat hereasons

motivatinghehypothesisouldhavebeen ikely o be "physical" atherhan mathematical",sincethere s no evidence hathe everworked ut a predictiveccount. Aristarchus,reyerconcludes, asthe ast Greekphilosopherwhoseriouslyttemptedo find hephysicallyruesystemftheworld"op. cit.,p. 149). Later stronomersadenoattemptodevelophehelio-centricmodel,probably ecauseofwhat eemed obe two nsuperablebjections,ne that hephysics f Aristotlelearlyhowed hat arthmust emaint rest t thecenter,ndtwo, hatthishypothesisould entail hat parallax ffectught o be seenfor tellarmovementsnlessthe starswere t an incomprehensiblyreat istance.ThesewerepreciselyheobjectionshatGalileohadtoovercomewomillenniaater.43In theeccentricmodel, heplanets' enter frotations not theearth ut a point loseto theearthwhich s either trest rmakes small ircle roundhe arth. nthe picyclemodel,

theplanet s carried n a smallerirclewhich otatesround largerircle.Thetwosystemswere arly een obegeometricallyquivalentnthe aseoftheouter lanets;nly heepicyclemodelwillwork or he nner lanets, hich old n tsfavor.44Simpliciusotes hat t was known hat he moonvaried napparentize on thebasisofdirect ndespeciallyf eclipse bservations;his,with hewell-knownrightnessariationsfVenus ndMars, ounted eavilyhe says)againstnykind f concentric odel InAristotelis



28/29

PRESIDENTIALADDRESS -MCMULLIN 63de Caelo,225b 39-226b). Autolycos f Pitanec. 310B.C.)wasthefirststronomereknowofwhoused his iscrepancyorejectoncentric odelsngeneral.

45QuotedbySimpliciusromAlexanderfAphrodisias,ho n turn squoting summarywrittenyGeminus,ftheMeteorologyf PosidoniusInanstotelishysicorumibrosQuattuorPriores,erlin:H. Dielsed., 1882,64v34 -65r2; translatednHeath, p. cit.,pp.275-6).Thisis typical f thesecond-handature f ourknowledgef Greek stronomy.incemost fthemajorworks avenotsurvived,erely nquotationsfquotations, ith ll thedangersfgarb-ling ttendantn this ractice.46Ptolemy'slmagest.TranslatedyG.J.Toomer.London:Duckworth,984,Preface,.36. I am ndebted o ProfessorlafPedersenor urdiscussionsf thedetails fPtolemaicndCopernicanstronomy.47Almagest,,5; p.42.48Almagest,, 8; p.45.49Almagest,, 3;p.40.50Almagest,, 7;my ranslation.51It stillhas a uniform otion, ut around point, heequant,whichs not thecenterfitsrotation.52He also had to introduce complicatedoublerockingmotion ftheepicycleirclesoaccount ormovementsn latitudedeparturesftheplanets rom he cliptic),raswemightput t,to compensateorhistakinghe ines fnodes ftheplanetary otionso intersectheearth nstead f the sun. Dreyeremarks:In no other art fplanetaryheory id thefunda-mental rror f thePtolemaicystemause o much ifficults inaccountingor he atitudes,andthese emainedhe hieftumbling-blockpto the ime fKepler"op.cit.,

Documents

Goals of Natural Science (1984)