The meaning of scientific propositions is not always expressible in terms of observable phenomena. Such propositions involve generalizations, and also terms that are theoretical constructs. I study here how to assess the meaning of scientific propositions, that is, the specific import of theoretical terms. Empiricists have expressed a concern that scientific propositions, and theoretical terms, should always be, to some degree, related to observable consequences. We can see that the former empiricist criterion of meaning only implies for theoretical terms not (...) to be definable in terms of observable, but that their use put a constraint on the observable consequences of a theory. To that effect, Ramsey's method of formal elimination of theoretical terms can be an interesting tool. It has faced important logical objections, which have mostly been addressed with respect to the problem of the ontological commitment of the second-order quantification they imply. I show here that these criticisms can be overcome, and that there can be a successful Ramsey elimination of theoretical terms with first order sentences, making Ramsey's method a relevant tool to assess the empirical meaning of scientific propositions. (shrink)

The focus here is on analytical and instrumental requirements for those collective decision exercises that lend themselves to a judgment-driven resolution. These have not as yet received much concerted technical attention from either of the two main movements in the field. They remain somewhere beyond the purview of the objectively-predicated instruments that mainstream GDSS (Group Decision Support System) designs tend to favour. Yet neither are they so inherently ill-structured as the situations with which the GDNSS (Group Decision and Negotiation Support (...) System) community is concerned, these usually allowing only a subjectively-predicated, compromisive or consensus-based conclusion. If the technical requirements peculiar to judgment-driven decision exercises are to be well met, it will be through the offices of analytical instruments that can help assure the rationality of the resolutions at which they arrive. The primary purpose of these pages is to offer some suggestions about the types of analytical instruments that might serve this end. (shrink)

Work on how to axiomatize the subtheories of a first-order theory in which only a proper subset of their extra-logical vocabulary is being used led to a theorem on recursive axiomatizability and to an interpolation theorem for first-order logic. There were some fortuitous events and several logicians played a helpful role.

A common aim of elimination problems for languages of logic is to express the entire content of a set of formulas of the language, or a certain part of it, in a way that is more elementary or more informative. We want to bring out that as the languages for logic grew in expressive power and, at the same time, our knowledge of their expressive limitations also grew, elimination problems in logic underwent some change. For languages other than that for (...) monadic second-order logic, there remain important open problems. (shrink)

In 1958, to refute the argument known as the theoretician's dilemma, Hempel suggested that theoretical terms might be logically indispensable for inductive systematization of observational statements. This thesis, in some form or another, has later been supported by Scheffler, Lehrer, and Tuomela, and opposed by Bohnert, Hooker, Stegmüller, and Cornman. In this paper, a critical survey of this discussion is given. Several different putative definitions of the crucial notion inductive systematization achieved by a theory are discussed by reference to the (...) properties of inductive inference. The consequences of the following differences between deductive and inductive inference are emphasized: the lack of simple transitivity properties (even in a modified sense) of inductive inference, and the failure of the inductive analogue of the converse of The Deduction Theorem. The main conclusions are: (i) Hempel's original thesis may very well be right but his argument for it is unsatisfactory, (ii) theoretical terms can be logically indispensable for a non-Hempelian kind of inductive systematization, relative to both Craigian and Ramseyan elimination, (iii) Lehrer's attempt to prove the indispensability of theoretical terms for inductive-probabilistic systematization is, as a modification of Hempelian kind of inductive-deterministic systematization, unsatisfactory, and (iv) there does not seem to be much hope of escaping the conclusion (ii), if it is true, by extending the Craigian replacement programme along the lines suggested by Cornman. (shrink)

Quine's reasons for recommending naturalist epistemology are: (1) knowledge, Mind and meaning are part of the world they have to do with, (2) since the cartesian quest for certainty and reductionism of carnap's 'aufbau' type have failed, Rational reconstruction has no more any advantage over psychology, (3) since phenomenalist validation of science is no longer our concern, It is not circular to appeal to psychology. Against this it is argued that (a) no definite methodological policy can be based on (1) (...) alone; (b) certainty and phenomenalist reduction are not the only purposes of rational reconstruction; (c) it would be circular to appeal to psychology in developing a theory of rational method of acquiring knowledge: (d) logic and psychology of science are complementary not mutually exclusive. (shrink)