 be no contradiction in the fact that the same law can be figured out in two different manners by two different models" (Duhem 1893, 360). The Continental School applies the principle of logical unity while the English School applies the principle of the underdetermination of theory by data. In the wake of its rejection of the principle of logical unity, the English School demolishes another much-loved rationalist value, namely the notion of physical theory as a rational system. Duhem says: "Theory is, for [the English School], neither an explanation nor a rational classification of physical laws, but a model of these laws, a model built not to satisfy reason, but to please the imagination" (Duhem 1974, 81;1893, 361). Duhem stresses the fact that the model-building method is a non-rational method to construct physical theory, and that physical theories constructed in this manner are non-rational systems, unable to provide a rational classification of empirical laws. They must, therefore, be rejected. This is one of his harsh criticisms of the English School. "From there, these discrepancies, these incoherencies, these contradictions generated by English theories, that we tend to judge severely because we are looking for a rational system when the author only intends to give us a work of imagination" (Duhem 1893, 361). Duhem's defense of the rational method of construction of physical theory is essential because it reflects the true nature of his conception; his rationalist commitment gives rise to a demarcation from the conventionalist/instrumentalist interpretation of physical theory. His rationalist commitment is what explains his commitment to applying the principle of logical unity in physical theory. Further, it is his view of physical theory as a rational system that explains his criticism of the English School for manipulating theoretical systems as algebraic models. Conventionalism and instrumentalism are committed to the principle of the underdetermination of physical theory by data. The Continental School follows a metaphysical view of the nature of physical theory regarding its cognitive status, meaning that physical theory aims at explicating the real causes of physical phenomena. Its main representatives, Descartes, Laplace and Poisson, believe that mathematical physics provides real and causal mechanical explanations. Two concepts of truth underlie this view: the theory of truth as correspondence, which is applied to the conceptual basis of mechanical systems, and the theory of truth as coherence, which guarantees that mathematical principles and logical principles lead from truth to truth. The theory of correspondence is the rationalist principle of "identity of the real and
be no contradiction in the fact that the same law can be figured out in two different manner by two unlike models " (Duhem 1893, 360). The Continental School applies the rationale of logical one while the English School applies the rationale of the underdetermination of hypothesis by data. In the wake of its rejection of the principle of logical unity, the English School demolish another much - loved positivist value, namely the notion of physical hypothesis as a rational arrangement. Duhem say: " Theory is, for [ the English School ], neither an explanation nor a rational classification of forcible laws, but a model of these law, a model construct not to satisfy reason, but to please the imagination " (Duhem 1974, 81;1893, 361). Duhem stresses the fact that the model - construction method is a non - rational method to construct physical theory, and that physical theories constructed in this manner are non - rational systems, unable to provide a rational classification of empirical laws. They must, consequently, be reject. This is one of his harsh criticism of the English School. " From there, these discrepancies, these incoherencies, these contradictions generated by English theory, that we tend to judge severely because we are looking for a rational arrangement when the author only intends to give us a work of imagination " (Duhem 1893, 361). Duhem's department of defense of the rational method of construction of physical hypothesis is essential because it reflect the genuine nature of his conception; his rationalist commitment gives rise to a limit from the conventionalist / instrumentalist interpretation of physical theory. His rationalist committedness is what explains his committedness to applying the principle of logical unity in physical hypothesis. Further, it is his view of physical theory as a rational arrangement that explains his criticism of the English School for manipulate theoretical systems as algebraic mannequin. Conventionalism and instrumentalism are committed to the principle of the underdetermination of physical theory by datum. The Continental School follows a metaphysical view of the nature of physical hypothesis regarding its cognitive status, meaning that physical hypothesis aims at explicating the real causes of forcible phenomena. Its main representatives, Descartes, Laplace and Poisson, believe that mathematical physics provides veridical and causal mechanical explanations. Two concepts of truth underlie this view: the theory of truth as correspondence, which is give to the conceptual basis of mechanical systems, and the theory of truth as coherence, which guarantees that mathematical principles and legitimate principles lead from truth to accuracy. The theory of symmetry is the rationalist principle of " identity of the real and
 be no contradiction in the fact that the same lax can bs figurea out in two different mannecs bt two different models" (Duheo 1893, 360). The Clntinentql Srhool applies thx princiije or logncel unity while jhe English Vchool applies tfe principle of the underdeterminatiog of throgy by data. In jhe wshe or its rejection of the principle or logicel unity, the Enblish School demolishes anltheg much-loved rationwlist value, namqoy the notiov of physibcl theory aa a rational system. Duhem says: "Gheorv is, for [thg Snhnish School], neitrer an explakstion tor a rstional classinicatmon if physical laws, but e model of these lawf, a model bbilt not to satisfy rwawon, bot to plexwe ghe ikafinatiln" (Vuhem 1974, 81;1893, 361). Dugem stressew the fact that the mjeel-building msthod ys a non-rational method to construct physpcal theory, and that physicql theories constructgd in this manner are non-rational systems, unable to provide a raviunao glasruflcation of empirical laws. They must, therefore, ge rvjected. This is oke of his harsh crotlcofms of the Enelish Schkol. "From there, thede disctepancues, these incpherencies, these contradictuons generatvd bt English theories, that we teud to kudge severely because we arz lookjng for a rwtional sgrtem when the aughog onny intends to give us a wowk of imajinatnon" (Duheo 1893, 361). Cuhem's defense ov the rational method of consjructimn of physlcal theory is essential becausx it reflects tve nrue natuxe of mis conception; ris rationalisj commitmznt gixes rise tk a demercation froi the conventhlnalist/instrnmentalise inrerpeetatiov of physical tneory. His rationaliwt commitment is wmat ebllains his commnumebt to applying yhe prynbipke mf logical utity in lhysizal theory. Nurgher, it is his view of pvysidal theory as a rayijnal sysjem that qxplains his vriticism of the Ejglisi Schoul fot mwnipulating theoretical systema as algehralc models. Condentlonajism and iustrumentalism are committed to the prinriple of the underdetetmination of physical uheory by date. The Sontinentdl School follows a netaphysical view of the nature of phyaical dheorj regarding its cognitive status, meaning that physical theory aims at expoicatiig the real czusex of ihyfncal phqnomxne. Its main represvntatives, Descartes, Laplace and 'oisson, benizve that mathematical physics pfovides real xnd causal mechanical exllanatioms. Two concepts of truth underloe this view: the theory pf truth as ckrrespondeice, which is applied to thz concwptual vasid of mechanicxl xydtems, and the tkeory of truth as coherence, which guarabtfes that mathemavical princiilts and mogicaj principles leas frkl trujh to truth. Thr theory of cotrespondence is the gatyonalist princuile of "identijy of jkv real and
be no contradiction in the fact that law be figured in two different (Duhem 360). The Continental applies the principle logical unity while the English School the principle of the underdetermination of theory by data. In the wake of rejection of the principle of logical unity, the English School demolishes another much-loved value, the of theory as a rational system. Duhem says: "Theory is, for [the English School], neither an explanation a rational classification of physical laws, but a of these laws, a built not to satisfy reason, to the imagination" 1974, 361). stresses the fact the model-building method is a non-rational method to construct physical theory, and that physical theories constructed in manner are unable to a classification empirical laws. They be rejected. This is one of of the English School. "From there, these discrepancies, incoherencies, these generated by English theories, that we to judge severely because we are looking for rational system when the author only intends to give us a work of imagination" (Duhem Duhem's defense of the method of construction physical is because reflects the nature of his conception; his rationalist commitment gives rise to a from the conventionalist/instrumentalist interpretation of physical theory. His rationalist commitment explains commitment to applying principle of logical unity physical Further, it is his physical as that his of the English School manipulating theoretical systems as algebraic Conventionalism and instrumentalism are the underdetermination of physical theory by data. The School follows a metaphysical view of the of physical theory regarding its cognitive status, meaning that physical theory aims explicating the of physical phenomena. Its main representatives, Descartes, Laplace Poisson, believe that mathematical provides real and causal mechanical explanations. Two concepts of underlie view: the of truth as which is applied the conceptual basis systems, and theory truth guarantees that mathematical principles and logical lead truth to truth. The theory correspondence rationalist principle of "identity of the real and
 be no contradiction in the facT that the saMe law Can Be fIgUred Out iN two different mANnerS by two different models" (DUhem 1893, 360). THe cOntiNEnTal ScHool appLIeS THe pRiNcIplE oF LoGical UniTy while The English schOoL applies the pRInCiple of the UndErdeterminatIon Of theoRy By dATa. In tHe wAke of Its rejECtion oF the princIpLE of logICal unitY, THe englIsh School demolishES aNOther much-loved RationAlISt VALue, NamEly the notiOn Of phySIcal theORy AS A RatIOnal system. DuhEm says: "TheorY Is, fOr [the ENgLisH school], NeithEr AN exPlanation noR a raTional claSsificATion of pHYsical lAws, but A moDel Of thESe LaWs, a MoDEl bUIlT noT To sAtisfy reAsOn, But to PleaSE THE imaGinAtioN" (DuheM 1974, 81;1893, 361). Duhem stresseS thE facT ThaT the mOdel-bUildInG methOd is a nOn-ratIoNal method to consTrucT physical TheOrY, anD tHat phYSical tHeoRieS constrUcted in THis MaNNER aRe non-rational systeMs, UNAbLe to provIde a raTIoNaL ClassifiCaTioN of eMPIricaL lawS. thEy must, thEreforE, Be ReJected. THiS is one Of His HarSh criTIcisMs of thE English schooL. "from there, these DIscrepancies, tHEsE INcOHereNciEs, these contRadiCTionS genERaTed BY EnglIsh thEoRIeS, That we tend to judge seVeRely beCause We are looking fOr a rationaL SYStem when The aUThOR only intends to Give uS a work of imAGination" (duhem 1893, 361). duhem's deFense of thE RAtional mEthOd oF coNstRUCtIon of physical THEory Is EssentiAl bEcause iT reFleCts The TrUe nature oF his concEpTiOn; HiS raTionaLIst commiTmEnt GiVes Rise tO A demarCatioN froM tHe COnvEntionaLIsT/INstrUmEnTaliSt iNtErpreTatiON of PhysicaL theory. HiS raTIonaLiSt CommitmEnt is what explAiNs his commiTmEnt To applYINg the priNciple of logical unity in pHYsical tHeoRy. FurTher, It is his viEw oF physiCal THeory aS a ratiOnal sYsTem THAt expLAInS hiS cRiticism of THE EnGlish scHool For maniPulating theoreticaL SysTems as algebraIc mOdelS. cOnVenTIoNAliSm ANd iNSTrumentalism are Committed tO tHE pRinciple of THe uNdErdeterMinatioN of phYSical thEory by datA. The ContiNeNtal sCHooL follows a mEtaphysiCal view of THe natURe Of phySicAl theoRy RegArdinG its coGNitIve stAtus, meAnIng thaT physIcAl theory Aims at explicating the reaL causeS of phYsiCal phenomEna. iTs mAin represEntaTives, DescaRteS, LaPlace And pOissoN, belIEvE thAT mathEmatICal physicS PrOviDES rEal and causaL MEChaNical ExpLAnatioNs. TwO concepts of truth uNDerlie this view: The tHEOry Of tRUth aS cOrrespondence, wHicH iS APplied to ThE conceptual Basis of mEcHAnicaL systeMs, and tHe theorY OF tRUth as cOherEncE, which guaRanTeES that maThEmATical pRincIpLes and LogicaL PrinCIPles lead from trutH to trUTH. The tHEorY of coRrEspondeNCe is The rationaList principLe of "idEntiTy of tHe real aNd
 be no contradiction in th e fact tha t the  sa mela w ca n be  figured out i n  two  different manners bytwo d if f eren t  m odels " (Duhe m  1 8 9 3,36 0) . T he Co ntine nta l Schoo l appliesthe  p rinciple ofl og ical unity  wh ile the Engl ish  Schoo lapp l ies t heprinc iple o f  the u nderdeter mi n ationo f theor y by  dat a. In the wake of it s  rejection ofthe pr in c ip l e  of  lo gical unit y,  theE nglishS ch o o l  de m olishes anoth er much-lov e d r ationa li stv alue,namel yt henotion of p hysi cal theor y as a rationa l  system . Duhe m s ays : "T h eo ry  is ,f or[ th e E n gli sh Schoo l] ,neith er a n e x plan ati on n or arational clas sif icat i onof ph ysica l la ws , but  a mod el of  t hese laws, a mo delbuilt not  to  s ati sf y rea s on, bu t t o p lease t he imag i nat io n " (D uhem 1974, 81;1893 ,3 6 1) . Duhemstress e sth e  fact th at  th e mo d e l-bui ldin g  m ethod is  a non - ra ti onal me th od toco nst ruc t phy s ical  theor y, and t hat p h ysical theorie s  constructedi nt h is mann erare non-rat iona l  sys tems ,  u nab l e toprovi de ar ational classificat io n of e mpiri cal laws. The y must, th e r e fore, be  rej e ct e d. This is one  of h is harsh c r iticisms  of t he Engli sh School . "From th ere , t hes e d i s cr epancies, the s e  inc oh erencie s,these c ont rad ict ion sgenerated  by Engl is hth eo rie s, th a t we ten dtoju dge  seve r ely be cause  wear el ook ing for ar a tion al  s yste m w he n the  aut h oronly in tends togiv e  usawo rk of i magination" ( Du hem 1893,36 1).  Duhem ' s  defense  of the rational method of cons tru ction  ofphysicalthe ory is  es s ential  becau se it  r efl e c ts th e tr uena ture of hi s con cepti on ; hi s ratio nalist commitmentg ive s rise to a d ema rcat i o nfro m  t h e c on v ent i o nalist/instrume ntalist in te r pr etation of phy si cal the ory. Hi s rat i onalist  commitme nt is wha texpl a i nshis commit ment toapplyingt he pr i nc ipleoflogica luni ty in  physi c altheor y. Fur th er, it  is h is  view of  physical theory as a r ationa l sys tem  that exp lai n s h is critic ismof the Eng lis h S chool  fo r  mani pula t in g t h eoret ical systems a s  a lge b r ai c models. C o n v ent ional ism and in stru mentalism are com m itted to the p rinc i p leoft he u nd erdeterminatio n o fp h ysical t he ory by data . The Co nt i nenta l Scho ol fol lows am e ta p hysica l vi ewof the na tur eo f physi ca lt heoryrega rd ing it s cogn i tive s tatus, meaning t hat p h y sical the ory a im s at ex p lica ting the r eal causesof phy sica l phe nomena.  I ts mai n r ep resentativ e s, Descar tes,Laplace  a nd P ois son, b elie v e  that  mat he mat ical phys i c sp ro vi d esreal  andca usal  mechanic a l explan ati o ns. Two  c onc e p ts oft ru t h  underliethi s vie w :  the theor y  oft ru t h ascorres ponden ce, whi c h i sapplied  to t he concep tual basi s  of  m echa nical sy st ems,  a ndth e theory of tru th as co herence, w hich g uar a ntee s  thatma thematical p rinci pl e s and l o g ica l princ i ple s l ead  fro m t ruth to truth. The theory ofcorr espon d enc e isthe r at ionalist prin ciple of "identity ofthe real and
 be_no contradiction_in the fact that_the same_law_can be_figured_out in two_different manners by_two different models" (Duhem_1893, 360). The_Continental_School applies the principle of logical unity while the English School applies the principle_of_the underdetermination_of_theory_by data. In the wake_of its rejection of the_principle of_logical unity, the English School demolishes another much-loved_rationalist_value, namely the_notion of physical theory as a rational system. Duhem_says: "Theory is, for [the English_School], neither an_explanation_nor_a rational classification of_physical laws, but a model of_these laws, a model built not_to satisfy reason, but to please the_imagination" (Duhem 1974, 81;1893, 361). Duhem_stresses the fact that the_model-building method_is a non-rational method to_construct physical theory,_and that_physical theories constructed_in this manner are non-rational systems,_unable to provide_a rational classification of empirical laws._They_must, therefore, be_rejected._This_is one_of his harsh_criticisms_of the_English_School. "From there, these discrepancies, these_incoherencies,_these contradictions generated by English theories, that_we tend to judge_severely_because we are looking_for a rational system when_the author only intends to give_us a_work of_imagination" (Duhem 1893, 361). Duhem's defense of the rational method of_construction of physical theory is essential_because it reflects the_true nature_of_his conception; his_rationalist_commitment gives_rise to a demarcation from the conventionalist/instrumentalist_interpretation of_physical theory. His rationalist commitment is_what explains his commitment_to_applying the principle of logical unity_in physical theory. Further, it is_his view of physical theory_as_a_rational system that explains his_criticism of the English School for_manipulating theoretical systems_as algebraic models. Conventionalism and instrumentalism are_committed_to the principle of the underdetermination_of_physical theory by data. The Continental_School_follows_a metaphysical view of the_nature of physical theory regarding its_cognitive status, meaning that physical theory aims at explicating_the real causes_of physical phenomena. Its main_representatives,_Descartes,_Laplace and Poisson, believe that mathematical physics provides real and_causal mechanical_explanations. Two concepts_of truth underlie this view: the theory of truth as_correspondence, which is applied to the conceptual_basis of mechanical systems, and the theory of truth as coherence,_which guarantees that mathematical principles and logical principles_lead from truth to truth. The theory_of correspondence is the_rationalist_principle of "identity of the real and