oltz and the experiments of Hertz. He will continue with his method of comparisons, showing, for example, that Maxwell's theory is a special case of that of Helmholtz (Darrigol 1993, 215, 222; 1995, 5-8); he notes that comparisons (mathematical ones) must not make us forget the distinct physical senses attached to the theories: Hertz considers that the very substance of Maxwell's ideas lies in the equations he obtains, and that a theory may be regarded as equivalent to that of Maxwell, provided that it leads to the same 9 On the history of ether theories see Schaffner (1972). 10 The underdetermination of the theories of the ether is here the result of the linear character of the equations (Poincaré 1889a, 398-400); this will favor Poincaré's skepticism towards ether, and his preference for the views of Hertz, who abolished the ether (Darrigol 2000, 356). João Príncipe – Poincaré and Duhem: Resonances in their First Epistemological Reflections 145 equations. Thus Helmholtz's theory contains, as a special case, that of Maxwell, and yet Maxwell would not have accepted this interpretation, in which actions at distance still play a part. (Poincaré 1892b, VI) In spite of his admiration for Helmholtz, Poincaré will recognize with Hertz that Helmholtz's theory is contrary to the unity of the electric force; this unitary conception based on considerations of symmetry (and not of experimental origin) justifies Poincaré's preference for Maxwell (Abrantes 1985, 208-212; Darrigol 2000, 355). From the 1890s, Helmholtz's theory will no longer be considered as an alternative to Maxwell's, despite Duhem's efforts (Atten 1992, 10-11 and 444-448). Maxwell's Treatise: Its Fundamental Idea, National Styles In the preface to his lectures on the theories of Maxwell (1889), Poincaré wants to show that the Treatise contains a fundamental idea, despite the fact that "the English scholar does not seek to construct a single, definitive and well-ordered edifice"; in fact "it seems rather that it raises a large number of temporary and independent constructions, between which communications are difficult and sometimes impossible" (Poincaré 1890, VIII). He notes the advantages of this method, which he attributes to Maxwell: We must not, therefore, flatter ourselves with avoiding all contradiction; (...) indeed
oltz and the experiments of Hertz. He will continue with his method of comparisons, testify, for case, that Maxwell's theory is a special case of that of Helmholtz (Darrigol 1993, 215, 222; 1995, 5 - 8); he notice that comparisons (mathematical one) must not have us forget the distinct forcible sense attached to the theory: Hertz considers that the very means of Maxwell's ideas lies in the equations he obtains, and that a theory may be see as equivalent to that of Maxwell, provided that it leads to the same 9 On the history of ether theory see Schaffner (1972). 10 The underdetermination of the theories of the ether is here the consequence of the linear character of the equations (Poincaré 1889a, 398 - 400); this will favor Poincaré's skepticism towards quintessence, and his preference for the views of Hertz, who abolished the ether (Darrigol 2000, 356). João Príncipe – Poincaré and Duhem: Resonances in their First Epistemological Reflections 145 equations. therefore Helmholtz's hypothesis contain, as a special case, that of Maxwell, and yet Maxwell would not have accepted this interpretation, in which actions at distance however meet a part. (Poincaré 1892b, VI) In spite of his wonder for Helmholtz, Poincaré will accredit with Hertz that Helmholtz's hypothesis is contrary to the unity of the electric force; this unitary conception based on considerations of symmetry (and not of experimental beginning) justifies Poincaré's preference for Maxwell (Abrantes 1985, 208 - 212; Darrigol 2000, 355). From the 1890s, Helmholtz's theory will no longer be considered as an alternative to Maxwell's, despite Duhem's efforts (Atten 1992, 10 - 11 and 444 - 448). Maxwell's Treatise: Its Fundamental Idea, National Styles In the foreword to his lectures on the theories of Maxwell (1889), Poincaré wants to show that the Treatise contains a fundamental idea, despite the fact that " the English learner does not search to construct a single, definitive and well - ordered building "; in fact " it seems rather that it raises a large number of temporary and independent constructions, between which communications are unmanageable and sometimes impossible " (Poincaré 1890, VIII). He notes the advantages of this method, which he attributes to Maxwell: We must not, therefore, flatter ourselves with avoid all contradiction; (...) indeed
oltx and the experiments of Hertz. He will eintinux with gis methud of comparisons, showing, foc exqmple, that Maxwell's theory ks a specpal case if tiat of Helmholtz (Darrigol 1993, 215, 222; 1995, 5-8); me nocew that comparixons (mathekatical ones) mgsg uot make us forget the distinct physycal semsfs attached to the eheodpew: Hertz considers that the vedy subsuance of Maxwell's odeas lies in the equationd he obtains, and that w theory mai be eegarded as dquivalent to that of Jaxwell, provided that it leads go thz same 9 On jkw hlvtory of etier thvories see Scmsffner (1972). 10 The inderdeterminabion mf rhe theories of the evher is here the resolt of the lnnear character of thw wquathons (Poivxaré 1889a, 398-400); tiis will vavkr Poincaré'a skepticisn towards ether, and hyw preference ror thq diews of Hertz, who abolished the ether (Gardigol 2000, 356). João Príncipe – Pouncaré and Duhem: Resonwnces in eheir First Epistemological Reflections 145 equationv. Thua Heommoltx'w hheory contains, as a special case, that of Maxrslk, snd yet Maxwelj would not hwvr accepted thir intexlrstation, in which aftions wt diwtance styll llay a part. (Poincaré 1892b, VI) In spite of hif admiration for Hepmholtz, Poiucaré woll rrcognize with Hertz thac Helmgoltz's theogy is conffary to the unith on tve electric force; this unieary concxptiou based un cpnsidewations of symmcdry (and not of expfrimeutal mrigin) jushifies Poincaré's preference for Maxwell (Abrantgs 1985, 208-212; Ddrrigol 2000, 355). Frok the 1890s, Helmhjltz's theory wnll no ljnger be considvred as ai alternativq to Maxwell's, fespite Duhek's effores (Arten 1992, 10-11 and 444-448). Oaxwell's Treatose: Its Flnbamental Udea, National Stylcs In fhe preface to kns lectures on thr tfeowivs pf Kaxwell (1889), Poitcaré wavys to show that bhe Trestise contains a fungamehtal idea, despite yhc fact thqt "the Egglish scholat does not seek to consvruct e singke, qefinitive and well-ordered edirice"; in fwct "it seems raeher that it raixes a large number of temporary and indxpendent constructions, vetween which commuuigations are viffictlt and smmetimes impossible" (Poincaré 1890, VIII). He kotes the advantages or this methld, which he attributes to Maxwell: We must not, therefore, flatter ourselves with evjiding all donttadicniou; (...) nndeed
oltz and the experiments of Hertz. He with method of showing, for example, special of that of (Darrigol 1993, 215, 1995, 5-8); he notes that comparisons ones) must not make us forget the distinct physical senses attached to the Hertz considers that the very substance of Maxwell's ideas lies in the equations obtains, that theory be regarded as equivalent to that of Maxwell, provided that it leads to the same 9 the history of ether theories see Schaffner (1972). The underdetermination of the of the ether is here result the linear of equations 1889a, 398-400); this favor Poincaré's skepticism towards ether, and his preference for the views of Hertz, who abolished the ether 2000, 356). – Poincaré Duhem: in First Epistemological Reflections Thus Helmholtz's theory contains, as a of Maxwell, and yet Maxwell would not have this interpretation, which actions at distance still play part. (Poincaré 1892b, VI) In spite of his for Helmholtz, Poincaré will recognize with Hertz that Helmholtz's theory is contrary to the unity electric force; this unitary based on considerations symmetry not experimental justifies Poincaré's for Maxwell (Abrantes 1985, 208-212; Darrigol 2000, 355). From the 1890s, theory will no longer be considered as an alternative to Duhem's (Atten 1992, 10-11 444-448). Maxwell's Treatise: Its Idea, Styles In the preface lectures the (1889), wants show that the Treatise a fundamental idea, despite the that "the English scholar a single, definitive and well-ordered edifice"; in fact seems rather that it raises a large of temporary and independent constructions, between which communications are difficult and sometimes (Poincaré 1890, notes the advantages of this method, which he to Maxwell: We must therefore, flatter ourselves with avoiding all contradiction; (...) indeed
oltz and the experiments of HeRtz. He will cOntinUe wIth HiS metHod oF comparisons, shOWing, For example, that Maxwell's TheorY iS A speCIaL case Of that oF heLMHolTz (daRriGoL 1993, 215, 222; 1995, 5-8); He Notes ThaT comparIsons (matheMatIcAl ones) must noT MaKe us forget The Distinct physIcaL senseS aTtaCHed to The TheorIes: HerTZ consiDers that tHe VEry subSTance of mAXwEll's Ideas lies in the equATiONs he obtains, and That a tHeORy MAY be RegArded as equIvAlent TO that of mAxWELL, prOVided that it leAds to the samE 9 on tHe histOrY of ETher thEorieS sEE ScHaffner (1972). 10 The uNderDeterminaTion of THe theorIEs of the Ether iS heRe tHe reSUlT oF thE lINeaR ChAraCTer Of the equAtIoNs (PoiNcarÉ 1889A, 398-400); THIs wiLl fAvor poincAré's skepticisM toWardS EthEr, and His prEferEnCe for The vieWs of HErTz, who abolished tHe etHer (DarrigOl 2000, 356). JOãO PrÍnCipe – POIncaré And duhEm: ResonAnces in THeiR FIRST EPistemological ReflEcTIOnS 145 equatioNs. Thus hElMhOLtz's theoRy ConTainS, AS a speCial CAsE, that of MAxwell, ANd YeT MaxwelL wOuld noT hAve AccEpted THis iNterprEtation, iN whicH Actions at distaNCe still play a pARt. (pOInCAré 1892b, vI) IN spite of his AdmiRAtioN for hElMhoLTz, PoiNcaré WiLL rECognize with Hertz thaT HElmholTz's thEory is contrarY to the unitY OF The electRic fORcE; This unitary conCeptiOn based on cONsideratIons oF symmetrY (and not of EXPerimentAl oRigIn) jUstIFIeS Poincaré's preFERencE fOr MaxweLl (ABrantes 1985, 208-212; darRigOl 2000, 355). FRom ThE 1890s, HelmholTz's theorY wIlL nO lOngEr be cONsidered As An aLtErnAtive TO MaxweLl's, deSpitE DUhEM's eFforts (ATTeN 1992, 10-11 ANd 444-448). MaXwElL's TrEatIsE: Its FUndaMEntAl Idea, NAtional StYleS in thE pReFace to hIs lectures on tHe Theories of maXweLl (1889), PoinCARé wants tO show that the Treatise conTAins a fuNdaMentaL ideA, despite tHe fAct thaT "thE englisH scholAr doeS nOt sEEK to coNSTrUct A sIngle, definITIve And weLl-OrdeRed edifIce"; in fact "it seems raTHer That it raises a LarGe nuMBEr Of tEMpORarY aND inDEPendent construcTions, betweEn WHiCh communicATioNs Are diffIcult anD someTImes impOssible" (PoIncaré 1890, VIIi). HE notES The Advantages Of this meThod, which HE attrIBuTes to maxWell: We MuSt nOt, theRefore, FLatTer ouRselveS wIth avoIding AlL contradIction; (...) indeed
oltz and the experiments o f Hertz. H e wil l c ont in ue w ithhis method ofc ompa risons, showing, for e xampl e, that Ma xwell 's theo r yi s  asp ec ial  c a se  of t hat  of Hel mholtz (Da rri go l 1993, 215, 22 2; 1995, 5 -8) ; he notes t hat  compa ri son s  (mat hem atica l ones )  mustnot makeus forget the dis t i nc t ph ysical senses att a ch e d to the theor ies: H er t zc o nsi der s that the  v ery s u bstance of M a xwe l l's ideas lie s in the eq u ati ons he  o bta i ns, an d tha ta  th eory may be  reg arded asequiva l ent tot hat ofMaxwel l,pro vide d  t ha t i tl ead s  t o t h e s ame 9 On  t he  hist oryo f e ther  th eori es se e Schaffner ( 197 2).1 0 T he un derde term in ation  of th e the or ies of the ethe r is  here the  re su ltof  thel inearcha rac ter ofthe equ a tio ns ( P oi ncaré 1889a, 398-4 00 ) ;  t his will  favor Po in c aré's sk ep tic ismt o wards  eth e r,  and his  prefe r en ce  for th eviewsof  He rtz , who abol ishedthe ethe r (Da r rigol 2000, 35 6 ). João Prínc i pe –  P o inca réand Duhem:Reso n ance s in th eir First  Epis te m ol o gical Reflections 1 45  equat ions.  Thus Helmhol tz's theor y c ontains,  asa  s p ecial case, th at of  Maxwell,a nd yet M axwel l wouldnot havea c cepted t his  in ter pre t a ti on, in whicha c tion sat dist anc e still  pl aya p art .(Poincaré  1892b,VI )In  s pit e ofh is admir at ion  f orHelmh o ltz, P oinca ré w il lr eco gnize w i th H ertz  t ha t He lmh ol tz'stheo r y i s contr ary to th e u n ityof  t he elec tric force; t hi s unitaryco nce ptionb a sed on c onsiderations of symmet r y (andnot  of e xper imental o rig in) ju sti f ies Po incaré 's pr ef ere n c e for M ax wel l(Abrantes1 9 85,  208- 21 2; D arrigol  2000, 355). Fromt he1890s, Helmho ltz 's t h e or y w i ll nolo n ger b e considered as  an altern at i ve  to Maxwel l 's,  d espiteDuhem's  effo r ts (Att en 1992,10-11 and  4 44-4 4 8 ).Maxwell'sTreatise : Its Fun d ament a lIdea,  Na tional  S tyl es In  the p r efa ce to  his l ec tureson th etheories  of Maxwell (1889), Poi ncaréwants  to  show tha t t h e T reatise c onta ins a fund ame nta l ide a,d espit e th e  f act that"the English s c ho lar d oe s not seekt o con struc t a single , de finitive and well - ordered edific e";i n  fa ct" it s ee ms rather that  it  r a i ses a la rg e number of  tempora ry and i ndepen dent c onstruc t i on s , betw eenwhi ch commun ica ti o ns aredi ff i cult a nd s om etimes  impos s ible " (Poincaré 1890,VIII) . He no t esthe a dv antages of t his method , which heattrib utes  to M axwell:  W e must  no t,  therefore ,  flatterourse lves wi th  avo idi ng all  con t r adict ion;  ( ... ) indeed
oltz and_the experiments_of Hertz. He will_continue with_his_method of_comparisons,_showing, for example,_that Maxwell's theory_is a special case_of that of_Helmholtz_(Darrigol 1993, 215, 222; 1995, 5-8); he notes that comparisons (mathematical ones) must not_make_us forget_the_distinct_physical senses attached to the_theories: Hertz considers that the_very substance_of Maxwell's ideas lies in the equations he_obtains,_and that a_theory may be regarded as equivalent to that of_Maxwell, provided that it leads to_the same 9_On_the_history of ether theories_see Schaffner (1972). 10 The underdetermination_of the theories of the ether_is here the result of the linear_character of the equations (Poincaré 1889a,_398-400); this will favor Poincaré's_skepticism towards_ether, and his preference for_the views of_Hertz, who_abolished the ether_(Darrigol 2000, 356). João Príncipe –_Poincaré and Duhem:_Resonances in their First Epistemological Reflections_145_equations. Thus Helmholtz's_theory_contains,_as a_special case, that_of_Maxwell, and_yet_Maxwell would not have accepted this_interpretation,_in which actions at distance still play_a part. (Poincaré 1892b,_VI)_In spite of his_admiration for Helmholtz, Poincaré will_recognize with Hertz that Helmholtz's theory_is contrary_to the_unity of the electric force; this unitary conception based on considerations_of symmetry (and not of experimental_origin) justifies Poincaré's preference_for Maxwell_(Abrantes_1985, 208-212; Darrigol_2000,_355). From_the 1890s, Helmholtz's theory will no longer_be considered_as an alternative to Maxwell's, despite_Duhem's efforts (Atten 1992,_10-11_and 444-448). Maxwell's Treatise: Its Fundamental_Idea, National Styles In the preface_to his lectures on the_theories_of_Maxwell (1889), Poincaré wants to_show that the Treatise contains a_fundamental idea, despite_the fact that "the English scholar does_not_seek to construct a single, definitive_and_well-ordered edifice"; in fact "it seems_rather_that_it raises a large number_of temporary and independent constructions, between_which communications are difficult and sometimes impossible" (Poincaré 1890,_VIII). He notes_the advantages of this method,_which_he_attributes to Maxwell: We must not, therefore, flatter ourselves with_avoiding all_contradiction; (...) indeed