 argument to show that explanatory hypotheses do not have empirical content of their own. Immediately after the logical argument, he offers an illustration by means of Newton's emission theory of light, which he took it to be a typical case of an explanatory theory. On this theory, light is formed of very small particles emitted with great velocities by light sources. These particles (the projectiles, as Duhem calls them) are subjected to distancedependent attractive and repulsive forces and permeate all bodies. This set of "essential hypotheses", linked (and only linked) with many others entail that light travels faster in water than in the air. This prediction, noted by François Arago, was tested by Léon Foucault in a famous experiment. Duhem was quick to point out that the negative result of the experiment (viz., that light travels faster in air than in water) does not tell where the error in Newton's emission theory lies. Hence, not only has Newton's explanatory hypothesis no empirical content in isolation of a theoretical system, but given a conflict between the theoretical system and experience, Newton's hypothesis can be saved from refutation. Hence, because of anti-atomism, an isolated explanatory hypothesis is not genuinely testable. What is more, Foucault's experiment is far from crucial. It does not prove the opposite theoretical hypothesis, viz., that light consists of waves. On this hypothesis, defended by Huygens, Young and Fresnel, light consists of waves which are propagated through an elastic luminiferous medium. This alternative explanatory theory yields the prediction that light travels faster in air than in water. One might have expected that we are faced here with a crucial experiment. It might be thought that we have two competing hypotheses H and H', H being that light consists of particles and H' being that light consists of waves, and a decisive experiment among them since H entails e and H' entails not-e. But this is the wrong way to think of the matter and anti-atomism brings out what's wrong with it. It is not two competing explanatory hypotheses that are being tested but two "theoretical groups or systems, each taken as a whole": Newton's optics and Huygens's optics (1894, 86). Given this, no experiment can decide between two explanatory hypotheses, viz., that light is a body and light is a vibration in a medium. These two explanatory hypotheses do not have their own empirical content. Still, could it be that under favourable circumstances a theoretical group or system ends up being
argument to show that explanatory hypotheses do not have empiric contentedness of their own. Immediately after the logical argument, he volunteer an example by means of Newton's emission hypothesis of light, which he took it to be a typical event of an explanatory theory. On this theory, lighter is formed of very small particle utter with great velocities by light sources. These particles (the projectile, as Duhem calls them) are subjected to distancedependent attractive and repulsive force and permeate all bodies. This set of " essential hypothesis ", linked (and only linked) with many others entail that light travel faster in water than in the air. This prediction, noted by François Arago, was tested by Léon Foucault in a celebrated experiment. Duhem was flying to point out that the negative result of the experiment (viz. , that light travels faster in air than in water) does not tell where the mistake in Newton's emission theory lie down. Hence, not only has Newton's explanatory hypothesis no empiric content in isolation of a theoretical arrangement, but given a conflict between the theoretical arrangement and experience, Newton's hypothesis can be saved from refutation. Hence, because of anti - atomism, an isolated explanatory hypothesis is not authentically testable. What is more, Foucault's experiment is far from crucial. It does not prove the opposite theoretical hypothesis, viz. , that inner light consists of wave. On this guess, defended by Huygens, Young and Fresnel, light consists of waves which are propagated through an elastic luminiferous medium. This alternative explanatory theory give the prediction that light travels faster in air than in water system. One might have expected that we are faced here with a all-important experiment. It might be thought that we have two competing hypotheses H and H', H being that luminosity consists of particle and H' being that light consist of waves, and a critical experiment among them since H entails e and H' entails not - e. But this is the improper way to think of the matter and anti - atomism brings out what's wrong with it. It is not two compete explanatory hypotheses that are being tested but two " theoretical group or systems, each taken as a whole ": Newton's optics and Huygens's optics (1894, 86). Given this, no experiment can decide between two explanatory hypotheses, viz. , that lighter is a body and light is a vibration in a medium. These two explanatory hypotheses do not have their own empiric content. Still, could it be that under favorable circumstances a theoretical group or system ends up being
 arhument to show that explxnatory hypotheses do iot havs empirizal content of their own. Immxdiarely qfter the logical arguoent, he ovfers an illnstration by meaia of Newton's slissnoi theory of ligmt, which he took it to be a tvpical case of an explanatory theory. On thix hheory, light if fogmqd or very small particles emitted witg great velocities bu light sources. These partlcled (the projectiles, ws Duhem caols eyem) are subjdcted to dpvtancedepehdent attractive and repulsive worcex and permgcre wnl bodies. Tiis sen of "essential hypothases", limked (and only kinned) with many others enteil that light travejs faster iu water than in the aur. This pregictkin, vottd uy Rrançoid Acago, was teated by Léon Foucault in a famois vcperiment. Dugem waf zuick to point out that the negative revulf of the experiment (viz., that light travels fwster in wir than in water) does not tell where the error it Newvov's tmlfruoj theory lies. Hence, not only has Newton's explwhauorj hypothesis no eipirical comtfny in isolation of a cgekretical system, buh given a cobflict beuween the theoretical system and experience, Uewron's hypothesis cau be saved fxom regutatoon. Hence, because of anci-atomjsm, an isolwted explzvatory hypothesir ix tot genuinely testable. Whae is more, Foueault's ebperoment ys far frol crughal. It does not prlve tke op[osite thelretical hypothesis, viz., that lijit consists og favvs. On thif hyppthesis, defenqed by Huygens, Young cnd Frdsnel, lighn consistv of waves rhich are pro[wgated throujh an elaftic lumuniferojr medium. This slternatine expoanatory theory yiclds jhs prediction thcu lught travels faxtef ig wic thag in water. Ona mieht nave dxpected thct we sre faced here with d crhcial experiment. Iy iight be thought that we have two competing hyplthesxs H aid H', H beyng that light consists of parficles anf H' being that jighb cogsists of caves, and a decisive experiment among thxm since H entails e ane H' entails not-e. Buj tmis is the wcong wwy to thitk of the matter and anti-atomism brinns out what's wrong witg it. Id is jot two competing explanatory hypotheses that are being tested but two "thworetiraj groups or sysyems, vack tcken as a wioue": Newton's opticx and Huygens's optics (1894, 86). Given tiis, no exparnment can decide between two rxolanatory hyputheses, viz., that light ia a body and light is a vibration in a kedium. These two explanabory hyporhesea do not heve their own empirival coutent. Wtill, ciuld it be that uvdet navourable cirrumatances a theoretical group or ststem wnfs up being
argument to show that explanatory hypotheses do empirical of their Immediately after the illustration means of Newton's theory of light, he took it to be a case of an explanatory theory. On this theory, light is formed of very particles emitted with great velocities by light sources. These particles (the projectiles, as calls are to attractive and repulsive forces and permeate all bodies. This set of "essential hypotheses", linked (and only with many others entail that light travels faster water than in the This prediction, noted by François was by Léon in famous Duhem was quick point out that the negative result of the experiment (viz., that light travels faster in air than water) does where the in emission lies. Hence, not Newton's explanatory hypothesis no empirical content a theoretical system, but given a conflict between theoretical system experience, Newton's hypothesis can be saved refutation. Hence, because of anti-atomism, an isolated explanatory is not genuinely testable. What is more, Foucault's experiment is far from crucial. It does the opposite theoretical hypothesis, that light consists waves. this defended Huygens, Young Fresnel, light consists of waves which are propagated through an elastic medium. This alternative explanatory theory yields the prediction that light in than in water. might have expected that are here with a crucial might thought two hypotheses and H', H being light consists of particles and being that light consists experiment among them since H entails e and entails not-e. But this is the wrong to think of the matter and anti-atomism brings out what's wrong with It is competing explanatory hypotheses that are being tested but "theoretical groups or systems, taken as a whole": Newton's optics and Huygens's optics 86). this, no can decide between explanatory hypotheses, viz., light is a light is vibration a explanatory hypotheses do not have their empirical Still, could it be that favourable theoretical group or system ends up being
 argument to show that explanaTory hypothEses dO noT haVe EmpiRicaL content of theiR Own. IMmediately after the logiCal arGuMEnt, hE OfFers aN illustRAtION by MeAnS of neWToN's emiSsiOn theorY of light, whIch He Took it to be a tYPiCal case of aN exPlanatory theOry. on this ThEorY, Light Is fOrmed Of very SMall paRticles emItTEd with GReat velOCItIes bY light sources. ThesE PaRTicles (the projeCtiles, As dUhEM CalLs tHem) are subjEcTed to DIstanceDEpENDEnt ATtractive and rEpulsive forCEs aNd permEaTe aLL bodieS. This SeT Of "eSsential hypOtheSes", linked (And onlY Linked) wITh many oThers eNtaIl tHat lIGhT tRavElS FasTEr In wATer Than in thE aIr. this pRediCTION, notEd bY FraNçois arago, was testeD by léon fOucAult iN a famOus eXpErimeNt. DuheM was qUiCk to point out thaT the Negative rEsuLt Of tHe ExperIMent (viZ., thAt lIght traVels fasTEr iN aIR THaN in water) does not telL wHERe The error In NewtON's EmISsion theOrY liEs. HeNCE, not oNly hAS NEwton's exPlanatORy HyPothesiS nO empirIcAl cOntEnt in ISolaTion of A theoretIcal sYStem, but given a cONflict between THe THEoREticAl sYstem and expErieNCe, NeWton'S HyPotHEsis cAn be sAvED fROm refutation. Hence, beCaUse of aNti-atOmism, an isolatEd explanatORY HypothesIs is NOt GEnuinely testabLe. WhaT is more, FouCAult's expErimeNt is far fRom cruciaL. iT does not ProVe tHe oPpoSITe Theoretical hyPOThesIs, Viz., that LigHt consiSts Of wAveS. On ThIs hypotheSis, defenDeD bY HUyGenS, YounG And FresnEl, LigHt ConSists OF waves Which Are pRoPaGAteD througH An ELAstiC lUmInifEroUs MediuM. ThiS AltErnativE explanatOry THeorY yIeLds the pRediction that LiGht travels FaSteR in air THAn in wateR. One might have expected thAT we are fAceD here With A crucial eXpeRiment. it mIGht be tHought That wE hAve TWO compETInG hyPoTheses H and h', h BeiNg thaT lIght ConsistS of particles and H' beINg tHat light consiSts Of waVES, aNd a DEcISivE eXPerIMEnt among them sinCe H entails E aND H' Entails not-E. but ThIs is the Wrong waY to thINk of the Matter and Anti-atomiSm BrinGS Out What's wrong With it. It Is not two cOMpetiNG eXplanAtoRy hypoThEseS that Are beiNG teSted bUt two "tHeOreticAl groUpS or systeMs, each taken as a whole": NewtOn's optIcs anD HuYgens's optIcs (1894, 86). gIveN this, no exPeriMent can decIde BetWeen tWo eXPlanaTory HYpOthESes, viZ., thaT Light is a bODy And LIGhT is a vibratiON IN a mEdium. theSE two exPlanAtory hypotheses do NOt have their own EmpiRICal ConTEnt. STiLl, could it be thaT unDeR FAvourablE cIrcumstanceS a theoreTiCAl groUp or syStem enDs up beiNG
 argument to show that exp lanatory h ypoth ese s d onothave  empirical con t entof their own. Immediat ely a ft e r th e  l ogica l argum e nt , heof fe rsan il lustr ati on by m eans of Ne wto n' s emission t h eo ry of ligh t,which he too k i t to b ea t y pical  ca se of  an ex p lanato ry theory .O n this theory, l ig ht i s formed of verys ma l l particles em ittedwi t hg r eat  ve locities b ylight sources .  T h e s e p a rticles (theprojectiles ,  as  Duhem  c all s  them)  aresu b jec ted to dist ance dependent  attra c tive an d  repuls ive fo rce s a nd p e rm ea teal l  bo d ie s.T his  set of"e ss entia l hy p o t h eses ",link ed (a nd only linke d)with man y oth ers e ntai lthatlighttrave ls  faster in wate r th an in the  ai r.  Th is  pred i ction,  no ted  by Fra nçois A r ago ,w a s  t ested by Léon Fouc au l t  i n a famo us exp e ri me n t. Duhem  w asquic k to po into ut  that th e nega t iv eresultof  the e xp eri men t (vi z ., t hat li ght trav els f a ster in air th a n in water) d o es n ot tell  wh ere the err or i n  New ton' s  e mis s ion t heory  l i es .  Hence, not only ha sNewton 's ex planatory hyp othesis no e m piricalcont e nt in isolation o f a t heoretical system,but g iven a c onflict b e t ween the  th eor eti cal s ys tem and exper i e nce,  N ewton's  hy pothesi s c anbesav ed  from ref utation.  H en ce ,bec auseo f anti-a to mis m,  an  isol a ted ex plana tory  h yp o the sis isn ot g enui ne ly  tes tab le . Wha t is mor e, Fouc ault's ex per i ment  i sfar fro m crucial. It  d oes not pr ov e t he opp o s ite theo retical hypothesis, viz . , thatlig ht co nsis ts of wav es.  On th ish ypothe sis, d efend ed  by H uygen s ,  Y oun gand Fresne l ,  li ght c on sist s of wa ves which are prop a gat ed through an  el asti c lu min i fe r ous  m e diu m .  This alternati ve explana to r ytheory yie l dsth e predi ction t hat l i ght tra vels fast er in air  t hani n  wa ter. One m ight hav e expecte d  that we  arefac ed her ewit h a c rucial exp erime nt. It  m ight b e tho ug ht thatwe have two competing h ypothe ses H  an d H', H b ein g  th at lightcons ists of pa rti cle s and  H' being  tha t  l igh t  cons ists of waves, an d a d ec isive exper i m e ntamong  th e m sinc e Hentails e and H'e ntails not-e.Butt h isist he w ro ng way to thin k o ft h e matter  a nd anti-ato mism bri ng s  outwhat's  wrong  with i t .  I t  is no t tw o c ompetingexp la n atory h yp ot h eses t hatar e bein g test e d bu t two "theoretical  grou p s  or s y ste ms, e ac h taken as a  whole": N ewton's opt ics an d Hu ygens 's opti cs  (1894 , 8 6) . Given th i s, no exp erime nt cande cide  be tweentwoe x plana tory  h ypo theses, v i z ., th at lig ht i s a b od y an d light i s  a vibra tio n  in a m ed ium . Theset wo e xplanatory  hy pothe s e s do not h a ve t h ei r  ownempiri cal co ntent.S til l,  coulditb e  that und er favour a ble  c ircu mstances  a  the or eti ca l group or syst em endsup being 
 argument_to show_that explanatory hypotheses do_not have_empirical_content of_their_own. Immediately after_the logical argument,_he offers an illustration_by means of_Newton's_emission theory of light, which he took it to be a typical case of_an_explanatory theory._On_this_theory, light is formed of_very small particles emitted with_great velocities_by light sources. These particles (the projectiles, as_Duhem_calls them) are_subjected to distancedependent attractive and repulsive forces and permeate_all bodies. This set of "essential_hypotheses", linked (and_only_linked)_with many others entail_that light travels faster in water_than in the air. This prediction,_noted by François Arago, was tested by_Léon Foucault in a famous experiment._Duhem was quick to point_out that_the negative result of the_experiment (viz., that_light travels_faster in air_than in water) does not tell_where the error_in Newton's emission theory lies. Hence,_not_only has Newton's_explanatory_hypothesis_no empirical_content in isolation_of_a theoretical_system,_but given a conflict between the_theoretical_system and experience, Newton's hypothesis can be_saved from refutation. Hence,_because_of anti-atomism, an isolated_explanatory hypothesis is not genuinely_testable. What is more, Foucault's experiment_is far_from crucial._It does not prove the opposite theoretical hypothesis, viz., that light_consists of waves. On this hypothesis,_defended by Huygens, Young_and Fresnel,_light_consists of waves_which_are propagated_through an elastic luminiferous medium. This alternative_explanatory theory_yields the prediction that light travels_faster in air than_in_water. One might have expected that_we are faced here with a_crucial experiment. It might be_thought_that_we have two competing hypotheses_H and H', H being that_light consists of_particles and H' being that light consists_of_waves, and a decisive experiment among_them_since H entails e and H'_entails_not-e._But this is the wrong_way to think of the matter_and anti-atomism brings out what's wrong with it. It_is not two_competing explanatory hypotheses that are_being_tested_but two "theoretical groups or systems, each taken as a_whole": Newton's_optics and Huygens's_optics (1894, 86). Given this, no experiment can decide between_two explanatory hypotheses, viz., that light is_a body and light is a vibration in a medium. These_two explanatory hypotheses do not have their own_empirical content. Still, could it be that_under favourable circumstances a_theoretical_group or system ends up being