Criticism and the Methodology of Scientific Research Programmes Author(s): Imre Lakatos Source: Proceedings of the Aristotelian Society, New Series, Vol. 69 (1968 - 1969), pp. 149-186 Published by: Blackwell Publishing on behalf of The Aristotelian Society Stable URL: http://www.jstor.org/stable/4544774 Accessed: 25/09/2009 17:03 Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://www.jstor.org/action/showPublisher?publisherCode=aristotelian. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit organization founded in 1995 to build trusted digital archives for scholarship. We work with the scholarly community to preserve their work and the materials they rely upon, and to build a common research platform that promotes the discovery and use of these resources. For more information about JSTOR, please contact [email protected]. The Aristotelian Society and Blackwell Publishing are collaborating with JSTOR to digitize, preserve and extend access to Proceedings of the Aristotelian Society. http://www.jstor.org Meeting of the AristotelianSociety at 21, Bedford Square, London, W.C.1, on Monday,28th October,1968, at 7.30 p.m. II-CRITICISM AND THE METHODOLOGYOF SCIENTIFICRESEARCH PROGRAMMES By IMRELAKATOS ?1. Introduction:Kuhn versusPopper. ?2. A clarification:Poppero, Popper,, and Popper2. (a) Popperoand dogmatic falsificationism.The empirical basis. (b) Popper1 and 'naive' falsificationism.The 'empirical basis'. (c) Popper2and growth. ?3. Scientificresearch-programmes; negative and positive heuristic. (a) Negativeheuristic. (b) Positiveheuristic. (c) A new look at crucialexperiments. (d) A note on 'metaphysicalresearch programmes'. ?4. Conclusion: the Popperian versus the Kuhnian research programme. ?1. Introduction:Kuhn versus Popper. For centuriesknowledge meant proven knowledge-proven eitherby the powerof the intellector by the evidenceof the senses. Wisdomand intellectualintegrity demanded that one must desist from unprovenutterances and minimise,even in thought,the gap between speculationand establishedknowledge. The proving powerof the intellector the senseswas questionedby the sceptics morethan two thousandyears ago; but they were browbeaten into confusionby the glory of Newtonianphysics. 150 IMRE LAKATOS Einstein'sresults again turned the tables and now very few philosophersor scientistsstill thinkthat scientificknowledge is, or can be, proven knowledge. But few realise that with this the wholeclassical structure of intellectualvalues falls in ruinsand has to be replaced:it is not enoughsimply to waterdown the idealof proven truth to the ideals of 'probabletruth' or 'truthby con- sensus'. Popper'sdistinction lies primarilyin his havinggrasped the full implicationsof the collapse of the best-corroboratedscientific theory of all times: Newtonian mechanicsand the Newtonian theory of gravitation. In his view virtue lies not in caution in avoidingerrors but in ruthlessnessin eliminatingthem. Boldness in conjectureson the one handand austerityin refutationson the other:this is Popper'srecipe. Intellectualhonesty then consists not in tryingto entrench,or establish,one's positionbut in speci- fying preciselythe conditionsunder which one is willing to give one'sposition up. Marxistsand Freudiansrefuse to specifysuch conditions:this is the hallmarkof their intellectualdishonesty. Belief may be a regretfullyunavoidable biological weakness to be kept underthe controlof criticism:but commitmentis for Popper an outrightcrime. Kuhn thinks otherwise. He too rejectsthe idea that science growsby accumulationof eternaltruths. He too takes his main inspiration from Einstein's overthrow of Newtonian physics. His main problem,too, is scientificrevolution. But accordingto Popper, scienceis 'revolutionin permanence',and criticismthe heartof the scientificenterprise; while according to Kuhn,revolu- tion is exceptionaland, indeed, extrascientific,and criticism,in 'normal times', is anathema. Indeed, for him the transition from criticismto commitmentmarks the point where progress -and 'normal' science-begins. For him the idea that on 'refutation'one can demand the rejection,the eliminationof a theory, is 'naive' falsificationism. Criticism of the dominant theory and proposal of new theories are only allowed in the rare moments of 'crisis'. This last Kuhnian thesis has been widelycriticised and I shall not discussit. My concernis rather CRITICISMAND THE METHODOLOGYOF SCIENTIFIC 151 RESEARCHPROGRAMMES that Kuhn, havingrecognised the failureboth of justificationism and falsificationismin providingrational accounts of scientific growth, seems now to fall back on irrationalism. While for Popper scientificchange is rational or at least rationallyrecon- structibleand thus falls in the realm of the logic of discovery, accordingto Kuhn scientificchange-from one 'paradigm'to another-is a mysticalconversion which is not and cannot be governedby rulesof reason:it falls totallywithin the realmof the (social) psychology of discovery.1 The clashbetween Popper and Kuhnis then not merelyover a technicalpoint in epistemology. The clash is over our central intellectualvalues, about the role and value of theoriesand critic- ism in the growth of knowledgein the post-Einsteinianperiod. The methodologicalimplications of the competingpositions reach beyond theoreticalphysics to the underdevelopedsocial sciences and even furtherinto moraland politicalphilosophy"a. In this paperI shallfirst show that in Popper'sphilosophy two differentpositions are conflated. Kuhnunderstands only Popper, the naive falsificationist(I shall call him Popper,),and his critic- ism of Popper1is correct. I shall even strengthenit. But Kuhn does not understanda more sophisticatedPopper-Popper2- whose rationalitygoes beyondnaive falsificationism. I shall try to explainPopper2's position and strengthenit, mainlyby stripping it of naive falsificationism. This improvedPopperian position may escape Kuhn'sstrictures and providea rationalexplanation of scientificrevolution. ?2. A clarification: Poppero,Popper,, Popper2. Let us see the conffictingtheses in some detail. I startwith a discussionof three frequentlyconflated positions whose authors I shall call Poppero,Popper1, and Popper2. lCp. his [1969]. For an ambiguityinthis Kuhnianposition cf. below,p.183, footnote 90. la According to Popper the number,faith or vocal energyof the prota- gonists of a theory-whether scientific or political-are irrelevant,for they have nothingto do with the truth-contentof that theory. Kuhn (like Polanyi) suggests that strength of commitment matters more than (possibly even constitutes) truth in science: and thereby lends-no doubt unintendedly- respectability to the political credo of contemporary religious maniacs ('student revolutionaries'). 152 IMRE LAKATOS (a) Popperoand dogmaticfalsificationism. Theempirical basis Accordingto Poppero,2Newton's theory of gravityis better than Descartes'sbecause Descartes's theory was refuted-proved false-by thefact that planetsmove in near-ellipticalpaths, and because Newton's theory explainedeverything that Descartes's theory had explained, and also explained the refuting facts. Analogously,according to Poppero,Newton's theory was, in turn, refuted-proved false-by the anomalousperihelion of Mercury, while Einstein'sexplained that too. Thus science proceedsby bold speculations,followed by hard, conclusiverefutations and followed again by still bolder, new, and, at least at the start, unrefutedspeculations. Accordingto Poppero,although science cannotprove, it can disprove:it 'can performwith completelogical certainty[the act of] repudiationof whatis false',that is, thereis an absolutelyfirm empiricalbasis of facts which can be used to disprovetheories. Poppero'sposition-as Popper constantlystresses-is unten- able: 'no conclusivedisproof of a theorycan ever be produced'.4 If one insists that 'refutation'consists in strictdisproof, one 'will neverbenefit from experience,and neverlearn from it how wrong [one iS]'.5 So we may just as well forget about Poppero.6 (b) Popper,and 'naive'falsificationism. The'empirical basis'. Kuhn's Popper, is much more sophisticated than Ayer's, Nagel'sand Medawar'snaive Poppero. Kuhnknows that Popper consistently condemns Poppero. But according to Kuhn this does not makeany realdifference. For, Kuhncontends, Popper1, 2 Popper0is the imaginaryauthor of a vulgarised version of Popperian philosophyof science,a phantomcreated by Ayer, Medawar,Nagel and others. I discuss him only because he is much more widely known than the more sophisticatedPopper1 and Popper2. 3 Medawar[1967], p. 144. Medawarcalls this 'one of the strongestideas in Popper'smethodology' and approves of it. Nagel, reviewing Medawar's book, criticisesMedawar for 'endorsingPopper's claims' ([1968],p. 70.) 4 Popper [1934],section 9. S Ibid. 6 The strawmanPoppero was originallyinvented by Ayer. Moreover,he invented also the myth that accordingto Popper 'definiteconfutability'