We define two extensions of Lewis’ S3 with two versions of Peirce’s Law. We prove that both of them have the Ackermann Property.

The scientist’s decision of accepting a given proposition is assumed to be dependent on two factors: the scientist’s ‘private’ information about the value of that statement and the proportion of colleagues who also accept it. This interdependence is modelled in an economic fashion, and it is shown that it may lead to multiple equilibria. The main conclusions are that the evolution of scientific knowledge can be path-dependent, that scientific revolutions can be due to very small changes in the empirical evidence, and that not all possible equilibria are necessarily efficient, neither in the economic nor in the epistemic sense. These inefficiencies, however, can be eliminated if scientists can form coalitions.

A system S has the “converse Ackermann property” (C.A.P.) if (A -> B) -> C is unprovable in S whenever C is a propositional variable. In this paper we define the fragments with the C.A.P. of some well-know propositional systems in the spectrum between the minimal and classical logic. In the first part we succesively study the implicative and positive fragments and the full calculi. In the second, we prove by a matrix method that each one of the systems has the C.A.P. Thus, we think the problem proposed in Anderson & Belnap (1975) § 8.12 has been solved.

In this paper it is assumed a broad conceptualization of Science which allows far looking into common practices which are apparently unstructured forms of knowledge. This result from a concept of culture which is the result of an hierarchization of behavior. In this theoretical framewark the concept of ethnoscience is analysed.

In this paper I review the different opinions held by scientists and philosophers as regards the status of the action-at-a-distance concept within relativistic physics. It is shown that in spite of the fact that the prevailing opinion has been that special relativity precludes actions at a distance, some important physicists have continued employing that concept throughout the present century. The key to understand that “anomalous” behaviour lies, in fact, in the relationships existent between quantum and classical physics (“inverse” principle of correspondence).

There are five basic types of ontology of law identified in relation with the singling out simpIe ontological objects in a strong or weak sense, dualist ontological objects, and complex ontalogical objects in a strong or weak sense. The conceptians of law far mulated in the theories/philosophies/ of law are ascribed to these five types.

The ’microcausality’ condition in quantum field theory is typically presented and justified on the basis of general principles of physical causality. I explore in detail a number of alternative causal interpretations of this condition. I conclude that none is fully satisfactory, independent of further and controversial assumptions about the object and scope of quantum field theories. In particular the stronger causalreadings require a fully reductionist and fundamentalist attitude to quantum field theory. I argue, in a deflationary spirit, for a reading of the ‘microcausality’ condition as merely a boundary condition, inspired by Relativity, that different possible formulations of quantum field theory must obey.