Modern methodology furnishes two partly competitive and partly complementary views on structure of the development of scientific investigation. According to the first view the development of science consists in enlargement of the set of empirical theorems; according to the other it consists, rather, in the narrowing of the set of possible theoretical hypotheses. A particular kind of assertion is associated with each of these views. The first is associated with the relation of assertion expressed in the statement: “the state α (...) of scientific investigationB forces us to accept the statement Τ”. The other view is associated with the relation of assertion expressed in the statement: “the state α of scientific investigationB admits the acceptance of the statement Τ”. Under a suitable definition of forcing we obtain the conclusion that intuitionistic logic is the class of only those formulas which we are forced to accept by every state of every scientific investigation. The notion of admission under a certain definition analogically leads to intuitionistic logic; on the other hand in the case of another, more natural definition, it leads to justification of a certain system of strict implication which is stronger than Lewis’ system S4 and which overlaps system S5.It can be said that assuming quite a natural definition of admission this system contains only those formulas the acceptance of which is admitted by every state of every scientific investigation. (shrink)

We have seen that the operational imperative is a prescriptive thesis about formulations of theories which imposes restrictions on the sorts of theories science may employ. We assessed the operational imperative by investigating a number of relationships holding between theory formulations, theories, physical systems, and phenomena, and then applying our findings to the operational imperative. These applications showed that the operational definitions required by the operational imperative were not definitions at all, being rather statements of putative empirical regularities holding between (...) particulars which in effect are formulations of empirically true or false theories. From this fact it followed that the supposed epistemic pay-offs of following the operational imperative fail to accrue: Operational definitions do not enable one to go deductively from knowledge of observables to knowledge of unobservables, and operational definitions do not provide a means for testing theories about unobservable phenomena. As such the operational imperative should be rejected in both its weak and strong versions. However, we did discover a grain of truth in the observational imperative — namely that theories with non-observable parameters are testable only if these parameters have observable manifestations. But that grain of truth does not lead to the operational imperative as typically advanced unless one embraces certain epistemological theories about observation which recent work on observation makes highly doubtful. (shrink)

Recently a number of philosophers have maintained that the meanings of terms in a scientific language are “theory-laden” or determined by the theory in which they occur, and thus that if the same term occurs in different theories, it will take on different meanings in the different theories; so the theories are incommensurable. An often-stated corollary to this doctrine is the claim that possessors of different theories cannot express or possess the same facts since they attach different meanings to the (...) terms used to give expression to the facts. Various attacks against this extreme doctrine on the relativity of facts have been mounted. Some of them consist in showing defective the argument advanced in support of this doctrine; but such criticisms at best show that the defenses offered for the doctrine are defective, not that the doctrine itself is defective. (shrink)