Stegm¨uller’s work received mixed response from both Kuhn and Feyerabend. Kuhn
welcomed Sneed’s formalism commenting that even an elementary structural form of Sneed captures significant features of scientific theory and practice notably absent from the earlier
formalisms.42
He further comments that
if only simpler and more palatable ways of representing the essentials of Sneed’s position can be found, philosophers, practitioners, and historians of science may, for the first time in years, find fruitful channels for interdisciplinary
communications.43
We will return to Kuhn’s critical comments after considering Feyerabend’s, Pearce’s and van Fraassen’s.
Feyerabend argues that both the claims of Stegm¨uller (1) that Kuhn’s thesis would
cease to have irrational consequences if we adapt the nonstatement view by rejecting the statement view, and (2) that nonstatement view no longer has problems with theoretical terms, incommensurability of rival paradigms etc., can be defused by showing that
(A) that the features rationalized by Stegmueller occur in Kuhn but not in science
and/or (B) that these features can also be explained by the statement view.44
Scientific theories as reconstructed by Stegm¨uller, Feyerabend says, are not immune to re-
moval by facts but only immune to certain types of removal such as refutation.45 Therefore,
the difference between the statement view and the nonstatement view “lies in the circum-
stances that bring about the demise of a theory.” The statement view methodologies, such as the Lakatosian methodology of research programs, have already shown how immunity of
a theory can be accounted for rationally.46
Feyerabend refers to certain episodes in science which can be better explained by the statement view. For example:
42
Kuhn ‘Theory-Change as Structure-Change: Commenting on the Sneed Formalism’ in Butts, R.E. and Hintikka J. 1977,Historical and Philosophical Dimensions of Logic, Methodology and Philosophy of Science, p. 290. Since Stegm¨uller adopts Sneed’s formalism, Kuhn’s comments on the latter apply also to the former.
43
Ibid,p. 291.
44
Feyerabend 1977, ‘Changing Patterns of Reconstruction’British Journal for the Philosophy of Science28 p. 359.
45
Ibid.
46
138 Chapter 5. Nature and Structure of Scientific Knowledge
The early quantum theory can be regarded as a paradigm (and was regarded as a research program by Lakatos) but there is no fixed underlying structure, no core in the sense of Sneed and Stegmueller, very fundamental assumptions such as the law of conservation of energy and momentum may be dropped and picked up again, and this is not just in special domains, as would be the case with special laws and expansions, but where ever the paradigm is applied. Moreover, this feature can be found not only in this particular period of the history of science
which was rather unruly but in more settled periods as well.47
A statement view, such as Lakatos, can deal with cases like these, because Lakatos’s core is a loose cluster of statements and is not as rigidly defined as the core, which permits an exchange of statements in such a manner that without change of paradigm the member statements in a cluster of statements can change. Therefore certain historical episodes of science can be better understood by the statement view. This is over and above the statement view’s ability to handle other features of Kuhn’s thesis, which both the statement view and nonstatement view can handle. Effectively, therefore, the statement view is better placed. Also, in the
‘context of application’ very rarely do scientists employ the entire structure of a theory.48
But, then there are advantages in the Sneed-Stegm¨uller reconstruction, which “puts
into relief certain features of science that almost disappear in the statement view.” They are: One minor example which is not mentioned by Stegmueller is the role of diagrams and models: chemical formulae are compared and combined according to strict rules but it would be somewhat artificial to regard them as statements. Of course, they can be used to produce statements, but they are not statements themselves and transformations leading from one formula to another do not go through a
statement phase. An even more important example is the role of a priori ele-
ments in our knowledge. Categories, forms of perceptions, are structures which
again give rise to statements (Kant’s synthetica prioristatements) without being
statements themselves.49
From these critical observations of Feyerabend one very important point emerges, which we further wish to exploit in the present thesis. The point can be put as follows: There exists a territory (the territory roughly demarcated by Feyerabend in the above quotation) that the nonstatement view alone can access. There are certain territories, specially those in the context of application, where the statement view has better access. And, insofar as the ‘middle’ territory, that part which both the views can handle well, is concerned, it would
remain unproblematic for methodological reconstructions. Stegm¨uller, so far has not shown
how the nonstatement view would work in that territory where it alone has access. All his
47 Ibid p. 361. 48 Ibid p. 361. 49 Ibid p. 359.
attempts are focussed in explicating the constructions of a finished scientific theory, and its applications, where the statement view also has a better hold. Therefore, we think that the strong point of nonstatement view remains undemonstrated. He seems to be working in a context that does not belong to a defender of the nonstatement view. We shall further strengthen this observation as we go through the critical comments of Thomas Kuhn.
David Pearce argues that the debate between the statement and nonstatement view is not substantive, i.e., an issue over which one can be judged better than the other. He thinks that
the force of Stegm¨uller’s advocacy of the nonstatement view would be dissipated
were it to turn out that the two positions are after all only equivalent ways of saying the same thing—what you can do with linguistic concepts you can also do
with structures, and conversely.50
Though, the structuralist approach based on Suppes’ notion of informal set-theoretic predi-
cate is able to treat the structure and dynamics of real scientific theories, Montague’s rigorous
formal axiomatizations of scientific theories “may be considered both philosophically valu- able and a practically useful tool within the formal language approach to the programme of
reconstruction”.51
Further, he says that:
Since a scientific theory is customarily written down , e.g. its empirical laws are
expressed by sentences of a language, considerable amount of technical dexterity
is required to paraphrase away its linguistic features in order to represent it in
set-theoretic form.52
Pearce’s attempt on the whole has been to show that the point of set-theoretic structural-
ist/nonstatement approaches depends on the linguistic basis of science.53 Thus Stegm¨uller’s
view does not address anything more in principle to the formal statement based model-
theoretic reconstructions of scientific theories. In fact, Stegm¨uller also says that the Montague
line of reconstruction of a scientific theory is in principle possible, though, he says, that we
need super-super Montagues to achieve the task. These observations suggest that except for the factor of degree of difficulty there seems to be not much difference between the two views with respect to reconstruction of a finished scientific theory. We take encouragement from
this situation to further strengthen our earlier conclusion that Stegm¨uller is trying to prove
his mettle in a wrong context, the context of reconstructing a mature scientific theory and
50
David Pearce 1981, ‘Is there any theoretical justification for a nonstatement view of theories?’ Synthese 46, p. 2. 51 Ibid pp. 3-8. 52 Ibid p. 7. 53 Ibid p. 34
140 Chapter 5. Nature and Structure of Scientific Knowledge
the context of application. We think that the context where a nonstatement view would fare
well is the context of theory formation and notafter a mature theory has been formulated.
Is it possible to define a set-theoretic predicate before a theory is historically de- veloped as a finished product? No, because it is reconstruction, it is post-hoc. However, is there any epistemological gain in the exercise? Yes, there seems to be some, because Kuhn’s observations about scientific revolutions appear more rational. But, what if Kuhn is proved
wrong? Stegm¨uller seems to be presuming the truthfulness of Kuhn’s observations, which can
be challenged. What is the worth of the nonstatement view independent of Kuhn’s thesis? Since the anatomy of a theory is rather clearly stated, it would have a role to
play in deciding whether something is a scientific theory or not. But again, Stegm¨uller’s
reconstruction is possible only for mathematically matured fields of inquiry such as physics. Is it necessary that only physics be considered the proper way of doing science?
Is there any implicit method that would generate the elements in the set of intended applications? If that were possible, then the reconstruction can suggest a logic of discovery. But no such role of the nonstatement view is suggested. Besides, if the identification (dis-
covery) of a physical system is theory or structure dependent, i.e., T-theoretical, pure a
posteriori identification of it would be impossible. It follows from Stegm¨uller’s account that any problem of application of a theory can be said to be solved only after the successful
incorporation of a physical system under a theory is achieved. Therefore, Stegm¨uller’s recon-
struction would help only in reinterpreting an application after the problem of application or in other words the problem of discovery is actually solved. Once the problem of discovery is solved, all the relevant epistemic factors, whatever they are, would already have entered and done their job. If the above observations are correct, then there seems to be no special and substantial epistemic role for the nonstatement view, apart from providing a semantics for a finished theory. Where lies the significance of the nonstatement view? The places identified
by Stegm¨uller do not appear to be satisfactory. Kuhn thinks of certain possibilities which
we shall discuss below after presenting van Fraassen’s critical comments on the nonstatement view.
While reflecting on the question of what sort of a thing a scientific theory is, van Fraassen tells us why he disagrees with the proponents of the nonstatement view. He defends
a view that a scientific theory must be the sort of thing that we can accept or reject and
believe ordisbelieve.54 Commenting on the view of Stegm¨uller that a theory is not the sort of thing which can properly be said to be true or false, he says:
54
This looks like a high price to pay. Don’t we believe, assert, deny, doubt, and disagree about theories? And do such propositional attitudes not presuppose at least that a theory is the sort of thing which can be true or false?
A theory is undoubtedly an object for epistemic evaluation. For van Fraassen it becomes
all the more important because theories can be appraised on the basis of certain a priori
qualities such as symmetry. (We will discuss separately the relation between symmetry and scientific knowledge below.) But it is not impossible for a defender of the nonstatement view to incorporate such features. It is also possible to reinterpret such “propositional attitudes”. A defender of the nonstatement view, for example, could reinterpret (and van Fraassen him- self sees this possibility) belief in a theory as a belief that the theory possesses a certain
relation to empirical reality, say by having relations to a set of applications.55
Similarly other propositional modes mentioned above can be reinterpreted.
Is it not possible to provide epistemological appraisal of concepts? Say as mean- ingful or not, as empirically relevant or not, as acceptable or not, as successful or not. The nonstatement view is not claiming anything other than saying that a scientific theory be un- derstood as a complex concept (or predicate). We do make choices between concepts, just as van Fraassen chooses ‘acceptability’ rather than ‘truth’ as a better expression in certain con- texts. Just as all instruments are not good for hunting, not all concepts are good for ‘hunting’ truth. Since it is possible to rate or value concepts as being useful or not, depending on the context, it is indeed possible for a nonstatement view to meet van Fraassen’s objection.
Further, is it not possible to introduce a dichotomy between scientific and non- scientific concepts? If it is possible it would become another level of epistemic evaluation of concepts (theories). We are aware of purely empirical and positivistic suggestions, such as cognitive significance based on verification, proposed by positivists and falsification, pro- posed by Popper. We think that along with empirical evaluation another complementary non-empirical (logical) evaluation would make such a dichotomy possible. Symmetry, van Fraassen’s favorite, is certainly one of the possible candidates for achieving such an objec- tive. The necessary relation between symmetry and inversion would make this new line of epistemic evaluation all the more interesting. More about this later (page 6.9).
Since theories are viewed as structures by both Stegm¨uller and van Fraassen and
since symmetry is a property of structures, we do not see why their positions cannot meet on the issue of the structure of scientific theories. We think that their meeting would have the effect of mutual reinforcement, and no one is required to pay any high price. There seems to be little or no room for differences between the structuralists and the constructive empiricists.
55
142 Chapter 5. Nature and Structure of Scientific Knowledge
Another cause of trouble in the nonstatement view, according to van Fraassen, is regarding the capacity of scientific theories to say what the world is like. Scientific theories are indeed about the world, otherwise they can’t be considered scientific. They are not just about the observable aspects, but also about the inaccessible and unobservable aspects. But at the same time the function (or the power) of science is not just to describe and explain our experienced world, but also to describe and explain other possible worlds. Thus van Fraassen says:
What does the theory say the world is like? and What does the theory say the
phenomena are like? Since the phenomena are just the observable part of the world, and since it is logically contingent whether or not there are other parts, it follows that these questions are not the same. Indeed, the second question is part of the first, in the sense that a complete answer to the latter is a partial answer to the former. The ‘non-statement view’ appears to deny the intelligibility of the
bigger question—but the question seems intelligible.56
The distinction between ‘the world’ and ‘the phenomena’ is inevitable, specially with re- gard to scientific knowledge, which cannot restrict its access to the world of phenomena alone. It is not clear, however, why he thinks that the nonstatement view denies or should deny the intelligibility of the bigger question. The set of intended applications, according
to the nonstatement view,need not be equivalent to the set of observable phenomena alone.
Besides the nonstatement view also speaks of physical systems as members of the class of applications, and not mere phenomena. This is also the point of the semantic approach van
Fraassen defends.57
Therefore, we think that van Fraassen’s objections are as unreasonable
as Stegm¨uller’s belief that the semantic approach is a statement view. The only notable
distinction between the semantic view and the nonstatement view is in the latter’s notion of
possible models Mp, (which is also the opinion of Kuhn) and therefore we should reconsider
the latter as an enrichment of the semantic approach rather than as a radical departure. The worthiness of the nonstatement view, let us repeat, consists in contexts other than those of reconstruction of finished theories, such as the reconstruction of theory formation. For the purposes of reconstructing finished theories the semantic approach is as good as the nonstate- ment view or any other statement views, whether the informal type of Lakatos or the formal variety of Montague. Since van Fraassen and other defenders of the semantic approach also believe that the nature of scientific knowledge consists in establishing the relation between the models on one hand with the physical systems on the other, whatever differences still
56
Ibid,p. 191.
57
Cf. ibid,p. 222, and also Giere 1979,Understanding Scientific Reasoning,and Suppe 1977,The Structure of Scientific Theories.
persist between them would not be of a substantial kind. They should therefore realize that there are more affinities than differences and if they come together it would be for mutual benefit.
Symmetry as a property of scientific construction, to be elaborated below, can with-
out trouble be incorporated by Stegm¨uller et al., and a conceptual view (if not the nonstate-
ment view) can be incorporated by van Fraassen et al. After all symmetry is a property of either a structure or a relation. An assertion is asymmetrical because the predicate ‘includes’
more than just the subject mentioned by an assertion, for it is a type, while the latter is a
token. Definitions, models and systems can be interpreted as structures, all of which can be called symmetrical. We therefore, do not see any problem, of either a formal or a sub- stantial kind, in viewing definitions, models and systems as nonstatements. We can always view—with appropriate interpretation—scientific assertions (call them laws or theories or whatever) as statements. What is required, to the best of our understanding, is that van Fraassen should and could without problem admit that definitions, models, systems etc., are
nonstatements, in the sense that they are constructions or structures. And Stegm¨uller should
and could without problem admit that scientific assertions, whether big or small, are indeed statements. The resulting view obtained by the reconciliation of the semantic and the non- statement views, would give rise to an enriched picture of scientific knowledge. Therefore, for
most purposes the semantic approach and Stegm¨uller’s structuralist view could come closer
than van Fraassen and Stegm¨uller think.
Another point requires clarification. The ‘bigger’ question mentioned above—‘What does the theory say the world is like?’ or what van Fraassen calls “the foundational question