Science continually contributes new models and rethinks old ones. The way inferences are made is constantly being re-evaluated. The practice and achievements of science are both shaped by this process, so it is important to understand how models and inferences are made. But, despite the relevance of models and inference in scientific practice, these concepts still remain contro-versial in many respects. The attempt to understand the ways models and infer-ences are made basically opens two roads. The first one is to (...) produce an analy-sis of the role that models and inferences play in science. The second one is to produce an analysis of the way models and inferences are constructed, especial-ly in the light of what science tells us about our cognitive abilities. The papers collected in this volume go both ways. (shrink)

The aim of this thesis dissertation is to propose a novel position in the debate on scientific realism, modal empiricism, and to show its fruitfulness when it comes to interpreting the cognitive content of scientific theories. Modal empiricism is an empiricist position, according to which the aim of science is to produce empirically adequate theories rather than true theories. However, it suggests adopting a broader comprehension of experience than traditional versions of empiricism, through a commitment to natural modalities. Following modal (...) empiricism, there are possibilities in nature, and constraints on what is possible, and a theory is empirically adequate if it correctly delimits the range of possible experiences. The position rests on a situated and pragmatic conception of natural modalities and of empirical confrontation. We claim that it can do justice to the empirical success of science, while not falling prey to the problem of theory change that undermines scientific realism. We explain how constraints of necessity on phenomena can be known by induction, and how this modal epistemology fits with scientific practice. Finally, we claim that a commitment to natural modalities allows for a rich interpretation of the cognitive content of theories. Modal empiricism could renew some metaphysical debates within a pragmatist framework, by tying them to experience and not being constrained by realist prejudices. -/- L'objet de cette thèse est de proposer une position originale dans le débat sur le réalisme scientifique, l'empirisme modal, et d'en démontrer la fructuosité quand il s'agit de tirer des enseignements du contenu cognitif des théories scientifiques. L'empirisme modal est une position empiriste, suivant laquelle le but de la science n'est pas de produire des théories vraies, mais des théories empiriquement adéquate. Cependant, il propose d'adopter un cadre plus large que les versions traditionnelles d'empirisme pour penser l'expérience, en incorporant un engagement envers les modalités naturelles, ou l'idée qu'il y a du possible dans la nature, et des contraintes sur les possibles. Nos théories sont empiriquement adéquates si elles délimitent correctement l'étendue des expériences possibles. Cette position s'appuie sur une conception située et pragmatique des modalités naturelles et de la confrontation empirique. Nous prétendons qu'elle est à même de rendre justice au succès empirique des sciences, sans pour autant faire face au problème du changement théorique qui mine le réalisme scientifique. Nous expliquons comment les contraintes de nécessité sur les phénomènes peuvent être connues à l'issue d'une induction, et en quoi cette façon de voir s'accorde avec la pratique scientifique. Enfin, nous affirmons qu'un engagement envers les modalités naturelles offre une richesse interprétative à même de renouveler, dans un cadre pragmatiste, plus ouvert que le réalisme, certaines questions métaphysiques tout en les ramenant à l'expérience . (shrink)

This paper intends to introduce the three issues of Principia which will appear in a sequel honoring Newton da Costa’s 80th birthday. Instead of presenting the papers one by one, as it is common in presentations such as this one, we have left the papers speak by themselves, and instead we have preferred to present to the Brazilian readers, specialty to our students, some aspects of Newton da Costa’s conception of science and of the scientific activity, grounded on the concept (...) of quasi-truth, which he contributed to develop in a rigorous way. Da Costa is known as one of the founding fathers of paraconsistent logic, but his contributions go also to the foundations of physics, theoretical computation, model theory, algebraic logic, lattice theory, applications of non-classical logics to law and technology, etc. But perhaps his main contribution was to provide a basis for the birth of a school of logic in our country, serving as teacher and inspiring new researchers for generations. It is a pleasure to have had so enthusiastic acceptation from the editors of Principia to organize these volumes. I would like to thank the contributors and the editors of Principia, specially Prof. Cezar Mortari for his help in organizing the issue. (shrink)

In this paper, a modest version of the Semantic View is motivated as both tenable and potentially fruitful for philosophy of science. An analysis is proposed in which the Semantic View is characterized by three main claims. For each of these claims, a distinction is made between stronger and more modest interpretations. It is argued that the criticisms recently leveled against the Semantic View hold only under the stronger interpretations of these claims. However, if one only commits to the modest (...) interpretation for all the claims, then the view obtained, the Modest Semantic View, is tenable and fruitful for the philosophy of science. (shrink)

In this paper I consider some logical and mathematical aspects of the discussion of the identity and individuality of quantum entities. I shall point out that for some aspects of the discussion, the logical basis cannot be put aside; on the contrary, it leads us to unavoidable conclusions which may have consequences in how we articulate certain concepts related to quantum theory. Behind the discussion, there is a general argument which suggests the possibility of a metaphysics of non-individuals, based on (...) a reasonable interpretation of quantum basic entities. I close the paper with a suggestion that consists in emphasizing that quanta should be referred to by the cardinalities of the collections to which they belong, for which an adequate mathematical framework seems to be possible. (shrink)

Quasi-set theory has been proposed as a means of handling collections of indiscernible objects. Although the most direct application of the theory is quantum physics, it can be seen per se as a non-classical logic (a non-reflexive logic). In this paper we revise and correct some aspects of quasi-set theory as presented in [12], so as to avoid some misunderstandings and possible misinterpretations about the results achieved by the theory. Some further ideas with regard to quantum field theory are also (...) advanced in this paper. (shrink)

In this paper, we examine the concept of particle as it appears in quantum field theories, focusing on a puzzling situation regarding this concept. Although quantum ‘particles’ arise from fields, which form the basic ontology of QFT, and thus a certain concept of ‘particle’ is al- ways available, the properties ascribed to such ‘particles’ are not completely in agreement with the mathematical and logical description of such fields, which should be taken as individuals.