I. Lakatos

1. I. Lakatos 2010春台大哲學系科學哲學第六講

2. Lakatos回應Kuhn • 一方面，Lakatos認為Kuhn把科學變遷基本上描繪成不具合理性的過程，在解讀科學變遷時，科學方法論無用武之地，反而是「暴民心理學」（mob psychology）才派得上用場。 • 這種非由理性主導的變遷過程，在Lakatos看來，不僅意謂著亂無章法，甚至具有認可非理性而鼓動盲目之強權的危險。

3. Lakatos回應Kuhn • 另一方面，Lakatos也看出Kuhn之訴諸科學史以提出哲學論證的威力，所以他試圖描繪出有關科學變遷的另一幅不同的圖像，其中理性仍居主導地位，藉此消除Kuhn對於科學理性所造成的危害。 • Lakatos因而積極從事科學史之理性重建（rational reconstruction）的工作，亦即使得歷史脈絡中的科學家在面對理論抉擇時所做出的選擇看起來儘可能是合理的。

4. Lakatos’s methodology of scientific research programs • Lakatos所謂的research program，大致上即相當於Kuhn的paradigm。research program如同paradigm一樣，不會因為有異例或是一時之間無法解決的問題的存在便遭否決。 • 在research program之指導下進行研究工作的科學家也同樣對research program具有相當大的信心。 • 但一個很大的差別是，同一時期在同一個領域裡並非只有一個research program。

5. Lakatos修正Popper • Lakatos試圖透過修正Popper說法之缺失而延續發展Popper的洞見： • 理論的測試不是雙方角力的關係，而是三邊角力的關係。 • 角力的結果也不是斷然的否證。

6. Lakatos修正Popper • Popper holds that “(1) a test is—or must be made—a two-cornered fight between theory and experiment so that in the final confrontation only these two face each other; and (2) the only interesting outcome of such a confrontation is (conclusive) falsification: ‘the only genuine discoveries are refutations of scientific hypotheses.’ However, history of science suggests that (1’) tests are –at least—three-cornered fights between rival theories and experiments and (2’) some of the most interesting experiments result, prima facie, in confirmation rather than falsification.”（Lakatos, I. (1978) The Methodology of Scientific Research Programmes, Cambridge University Press, p. 31.）

7. Lakatos修正Popper • As Lakatos notes, the history of science is not consonant with the Popperian model. For theories have not in fact been jettisoned just because they have led to a prediction which was not borne out. Indeed….to abandon a theory simply because it generated an anomaly would be to subvert the entire scientific enterprise. In such two-cornered match victory would go to the world every time. There has been no theory, no matter how successful, that has not generated some anomalies from its inception until its demise. The generation of anomalies is not a sufficient condition for rejecting a theory. For a theory with anomalies is better than no theory at all.

8. Lakatos修正Popper • Lakatos maintains that “an assessment of the relative merits of competing theories should be delayed until proponents of the theories have had time to explore modifications in their theories which might make them better able to cope with anomalies. One should not simply reject a theory T for a better and entirely different theory T’ without exploring the possibility that some agreeable modification in T would produce a theory better than T or T’. This entirely acceptable suggestion leads Lakatos to the view that the unit of appraisal should not be a single theory but a sequence of theories in which each theory is generated by modifying its predecessor. Such a sequence is called a scientific research programme.”

9. Scientific Research Programme • If the unit of appraisal is not a theory but a sequence of related theories, some criterion is required for determining which theories constitute a particular SRP. • Lakatos seeks to individuate research programmes through a specification of their three components: the hard-core, the negative heuristic and the positive heuristic.

10. Scientific Research Programme • The hard-core of an SRP consists of a family of theoretical assertions and any theory which is part of the SRP must share those assumptions. • The negative heuristic of the programme is a methodological principle stipulating that the components in the hard-core are not to be abandoned in the face of anomalies…By appeal to the negative heuristic, anomalies arising in the application of the theory are not taken as refuting these postulates. The tension generated by anomalies is to be eased through the modifications of either auxiliary hypotheses, observational hypotheses or hypotheses specifying initial conditions. • Guidance on what is to be done in the face of anomalies is provided by the positive heuristic of the programme.

11. Hard Core • The hard core of a programme：some very general theoretical hypotheses。例如： • 哥白尼天文學的hard core: the assumptions that the earth and the planets orbit a stationary sun and that the earth spins on its axis once a day • 牛頓物理學的hard core: Newton’s laws of motion plus his law of gravitational attraction.

12. Hard Core • 馬克斯歷史唯物論的hard core: the assumption that social change is to be explained in terms of class struggle, the nature of the classes and the details of the struggle being determined in the last instance by the economic base. • 19th century Darwinian research program的hard core: different biological species are linked by descent and form a family tree（or perhaps a very small number of separate trees）+ changes in biological species are due mostly to the accumulation of tiny variations favored by natural selection, with some other causes of evolution playing a second role.

13. Hard Core • The hard core of a programme is rendered unfalsifiable by the methodological decision of its protagonists.

14. Protective Belt • The protective belt consists not only of explicit auxiliary hypotheses supplementing the hard core but also assumptions underlying the description of the initial conditions and also observation statements.例如： • 哥白尼天文學中的周轉圓，恆星與地球之間距離的假定等等。 • 牛頓力學中detailed ideas about matter; a view about the structure of the universe; and mathematical tools used to link the hard core to real phenomena. • Darwinism中的detailed ideas about which species are closely related to which; ideas about inherence, variation, competition, and natural selection; ideas about the distribution of organisms around the earth, etc.

15. Negative Heuristic • Negative heuristic is the stipulation that the basic assumptions underlying the hard core must not be rejected or modified or the demand that during the development of the programme the hard core is to remain unmodified and intact.

16. Positive Heuristic • Positive heuristic include rough guidelines indicating how the research programme might be developed. Such development will involve supplementing the hard core with additional assumptions in an attempt to account for previously known phenomena and to predict novel phenomena. • The positive heuristic tells scientists how to solve problems using the theory and how to respond to anomalies by revising the protective belt. Included also a fairly definite experimental programme.

17. Positive Heuristic • In the case of the Newtonian SRP Lakatos describes the positive heuristic as a plan for developing increasingly sophisticated models of the sun’s planetary system. The first in this sequence of models has a fixed, point-like sun and a single point-like planet. This is replaced by a model with the sun and the planet revolving around their common center of gravity, which is in turn supplanted by one with more than one planet. In the next the sun and the planets are treated not as point-like but as extended symmetrical masses and eventually interplanetary forces are introduced and the planets are allowed to be non-symmetrical…

18. Lakatos’ Insights • We can see that Lakatos has discerned two important facets of scientific procedure. • First, scientists properly have a sufficient degree of faith in their basic theoretical postulates, the hard-core, that anomalies are explained away. These postulates are not up for the easy falsification in the face of anomalies that Popper presumes. • None the less anomalies have to be dealt with and Lakatos’s second insightful point is that scientists may have some very general guiding ideas (the positive heuristic) about how one should try to cope.

19. Scientific Research Programme • Work within a single research programme include: • the expansion and modification of its protective belt by the addition and articulation of various hypotheses; • no ad hoc hypotheses; • modifications or additions to the protective belt must be independently testable.

20. Scientific Change • Lakatos’s principles of scientific change： • (1) Changes should only be made to the protective belt, never to the hard core. • (2) Changes to the protective belt should be progressive.

21. Scientific Change • A progressive research program constantly expands its application to a larger and larger set of cases, strives for a more precise treatment of the cases it presently covers, and succeeds in increasing its predictive power. • Each field will have a collection of research programs at any given time, some of which are progressing rapidly, others progressing slowly, and others degenerating.

22. Rationality • For Lakatos, it is acceptable to protect a research program for a while, during a period when it is degenerating. It might recover. This is even the case when another research program has overtaken it. • The history of science contains cases of research programs recovering from temporary bad periods. So a reasonable person can wait around and hope for a recovery. • But how long is it reasonable to wait? • Lakatos does not say.

23. Scientific Change • “A research programme is said to be progressing as long as its theoretical growth anticipates its empirical growth, that is, as long as it keeps predicting novel facts with some success; it is stagnating if its theoretical growth lags behind its empirical growth, that is, as long as it gives only post hoc explanations either of chance discoveries or of facts anticipated by, and discovered in, a rival programme. If a research programme progressively explains more than a rival, it ‘supersedes’ it, and the rival can be eliminated.” （Lakatos, I. (1978) The Methodology of Scientific Research Programmes, Cambridge University Press, p. 112.）

24. Scientific Change • In this characterization of a progressive SRP we see on the one hand Popperian-like stresses on the importance of increasing content and of avoiding ad hoc moves. On the other hand, it is hoped that corroboration could come to play a positive evidential role so that successful predictions would not merely show that a theory had not been refuted. They would provide a reason for thinking that the SRP which has generated them has something in it.

25. Rationality • Is there a third rule that tells us how to handle decisions between research programs? • Not really. Lakatos did say that the decision to stay with a degeneration research program is a high-risk one. But he does not give us a rule for when a rational scientist should give up on one research program and switch to another. It seems that the whole point of Lakatos’s project was to give us a way of retrospectively describing episodes in science as rational.

26. Rationality • Does Lakatos’s picture of the structure of science have any useful elements? • It seems that some fields may have dominant paradigms and Kuhnian normal science. Others may have competing research programs. Some might have very general paradigms plus lower-level research programs budding off periodically. • In short, there are some fields where Lakatos’s picture of the structure of science seems a far more accurate description of what goes on than Kuhn’s paradigm-based view.