Projet En développant son « empirisme constructif », Bas Van Fraassen est devenu une référence incontournable pour la philosophie des sciences contemporaine. Après la vague de critiques qui, vers les années 1960, avait fait perdre à l'empirisme logique sa prédominance dans le champ des idées, le réalisme scientifique semblait s'être imposé comme le seul compte rendu acceptable du travail et des orientations de la recherche. Quine avait beau énoncer ce que pourrait être un empirisme affranchi de ses deux « (...) dogmes » (l'intangibilité de la distinction vérités analytiques / vérités synthétiques, et la réduction des constructions aux « faits »), le programme d'une philosophie des sciences empiriste renouvelée restait à l'état d'esquisse. Mais par trois ouvrages successifs, Scientific Image (1980), Laws and symmetry (1989), et Quantum mechanics an empiricist view (1991), Van Fraassen a posé les bases d'un empirisme viable, parce que capable de prendre en charge la plupart des spécificités dont se prévaut le réalisme contre l'empirisme classique ou logique, et de rendre raison des développements les plus actuels de la physique. Contre l'empirisme classique ou logique, les réalistes font d'abord valoir que la réduction de toute réalité et de tout acte de référence aux phénomènes, ne rend justice ni à la pratique du langage courant ni à celle des sciences. Lorsque quelqu'un procède à une dénomination, il ne cherche pas à désigner par là une tranche d'apparaître, ou quelque ensemble fini et répertorié d'apparitions; il pointe vers "quelque chose" dont les modalités de manifestation sans fin assignable sont pour partie anticipées et pour partie ouvertes. De même, quand un chercheur scientifique parle de l'objet de ses investigations, il ne limite pas son discours à un ensemble fini de résultats d'expérience obtenus sous des conditions instrumentales actuellement disponibles; il renvoie à une entité dont la variété des manifestations futures est prévue aussi complètement que possible (et avec un succès croissant) par des cadres conceptuels et théoriques révisables. Face à cette objection, Van Fraassen fait jouer un rôle capital aux modèles dans sa version de l'empirisme.. (shrink)

Bas C. van Fraassen presents an original exploration of how we represent the world.

What is empiricism and what could it be? Bas . van Fraassen, one of the world’s foremost contributors to philosophical logic and the philosophy of science, here undertakes a fresh consideration of these questions and offers a program for renewal of the empiricist tradition. The empiricist tradition is not and could not be defined by common doctrines, but embodies a certain stance in philosophy, van Fraassen says. This stance is displayed first of all in a searing, recurrent critique (...) of metaphysics, and secondly in a focus on experience that requires a voluntarist view of belief and opinion. Van Fraassen focuses on the philosophical problems of scientific and conceptual revolutions and on the not unrelated ruptures between religious and secular ways of seeing or conceiving of ourselves. He explores what it is to be or not be secular and points the way toward a new relationship between secularism and science within philosophy. (shrink)

What is empiricism and what could it be? Bas C. van Fraassen, one of the world’s foremost contributors to philosophical logic and the philosophy of science, here undertakes a fresh consideration of these questions and offers a program for renewal of the empiricist tradition. The empiricist tradition is not and could not be defined by common doctrines, but embodies a certain stance in philosophy, van Fraassen says. This stance is displayed first of all in a searing, recurrent critique (...) of metaphysics, and second in a focus on experience that requires a voluntarist view of belief and opinion._ _Van Fraassen focuses on the philosophical problems of scientific and conceptual revolutions and on the not unrelated ruptures between religious and secular ways of seeing or conceiving of ourselves. He explores what it is to be or not be secular and points the way toward a new relationship between secularism and science within philosophy. (shrink)

Psillos has recently argued that van Fraassen’s arguments against abduction fail. Moreover, he claimed that, if successful, these arguments would equally undermine van Fraassen’s own constructive empiricism, for, Psillos thinks, it is only by appeal to abduction that constructive empiricism can be saved from issuing in a bald scepticism. We show that Psillos’ criticisms are misguided, and that they are mostly based on misinterpretations of van Fraassen’s arguments. Furthermore, we argue that Psillos’ arguments for his claim that (...) constructive empiricism itself needs abduction point up to his failure to recognize the importance of van Fraassen’s broader epistemology for constructive empiricism. Towards the end of our paper we discuss the suspected relationship between constructive empiricism and scepticism in the light of this broader epistemology, and from a somewhat more general perspective. (shrink)

Professor Massey's exposition and analysis [5] of Professor Grünbaum's writings on metric aspects of space seem to me both very helpful in understanding those writings and to contain a considerable original contribution to the subject. Nevertheless I would like to argue that there is an alternative to Massey's explication which seems to me more faithful to Grünbaum's remarks; it seems at least to have the virtue of not forcing Grünbaum to reject the usual mathematical definitions of the notions used.

Rescorla explores the relation between Reflection, Conditionalization, and Dutch book arguments in the presence of a weakened concept of sure loss and weakened conditions of self‐transparency for doxastic agents. The literature about Reflection and about Dutch Book arguments, though overlapping, are distinct, and its history illuminates the import of Rescorla's investigation. With examples from a previous debate in the 70s and results about Reflection and Conditionalization in the 80s, I propose a way of seeing the epistemic enterprise in the light (...) of practical requirements to be met by demands for synchronic coherence and probability updating policies. This includes a defense of principles rejected by Rescorla, while allowing for the value of his results in the borderland between theories of cognition and formal epistemology. (shrink)

A basic aim of E. Beth's work in philosophy of science was to explore the use of formal semantic methods in the analysis of physical theories. We hope to show that a general framework for Beth's semantic analysis is provided by the theory of semi-interpreted languages, introduced in a previous paper. After developing Beth's analysis of nonrelativistic physical theories in a more general form, we turn to the notion of the 'logic' of a physical theory. Here we prove a result (...) concerning the conditions under which semantic entailment in such a theory is finitary. We argue, finally, that Beth's approach provides a characterization of physical theory which is more faithful to current practice in foundational research in the sciences than the familiar picture of a partly interpreted axiomatic theory. (shrink)

Criteria of adequacy for scientific representation of the phenomena pertain to accuracy and truth. But that representation is selective and may require distortion even in the selected parameters; this point is intimately connected with the fact that representation is intentional, and its adequacy relative to its particular purpose. Since observation and measurement are perspectival and the appearances to be saved are perspectival measurement outcomes, the question whether this “saving” is an explanatory relation provides a new focus for the realist/antirealist debate. (...) The Born rule and von Neumann's “collapse” postulate in quantum mechanics provide a telling case for this question in recent physics. (shrink)

Metaphysicians speak of laws of nature in terms of necessity and universality; scientists, in terms of symmetry and invariance. In this book van Fraassen argues that no metaphysical account of laws can succeed. He analyzes and rejects the arguments that there are laws of nature, or that we must believe there are, and argues that we should disregard the idea of law as an adequate clue to science. After exploring what this means for general epistemology, the author develops the (...) empiricist view of science as a construction of models to represent the phenomena. (shrink)

In this book van Fraassen develops an alternative to scientific realism by constructing and evaluating three mutually reinforcing theories.

What is empiricism? There can be no authoritative answer to any such question. A historian of philosophy can at best try to call what is common to philosophers who either identified themselves, or have traditionally been identified, as empiricists. But what has set those philosophers apart from others, and especially from those whom they criticized, may not be captured in common views or doctrines. The historian may, in trying to fix the label, rely tacitly on a view of what philosophical (...) positions are and how they are to be identified. Finally, it is typical of philosophers who decide to range themselves under some pre-existing banner ("empiricism", "pragmatism", "phenomenology") to change the very philosophy they take on, as much as did their historical heroes in their day. I will here try to give a sustained argument about what empiricism cannot be, and then enter upon a tentative exploration of what it should be (taken to be). (shrink)

Bas C. van Fraassen                          Princeton University       My topics today are the relation between science and myth, and the possibility of empiricism as an approach to life as well as to science. But philosophy is a thoroughly historical enterprise, a dialogue that continues in the present but is always almost (...) entirely shaped by our past. So I will devote the first half of this talk to setting the historical stage. (shrink)

In The Inference That Makes Science, Ernan McMullin recounts the clear historical progress he saw toward a vision of the sciences as conclusions reached rationally on the basis of empirical evidence. Distinctive of this vision was his view of science as driven by a specific form of inference, retroduction. To understand this properly, we need to disentangle the description of retroductive inference from the claims made on its behalf. To end I will suggest that the real rival to McMullin's vision (...) of science is not the methodologies he criticizes so successfully but a more radical empiricist alternative in epistemology. (shrink)

A scientific theory offers models for the phenomena in its domain; these models involve theoretical quantities, and a model's structure is the set of relations it imposes on these quantities. A fundamental demand in scientific practice is for those quantities to be clearly and feasibly related to measurement. This demand for empirical grounding can be articulated by displaying the theory-dependent criteria for a procedure to count as a measurement and for identifying the quantity it measures.

The attempt to formulate a viable empiricist and non-foundationalist epistemology of science faces four problems here confronted. The first is an apparent loss of objectivity in science, in the conditions of use of models in applied science. The second derives from the theory-infection of scientific language, with an apparent loss of objective conditions of truth and reference. The third, often cited as objection to The Scientific Image, is the apparent theory-dependence of the distinction between what is and is not observable. (...) The fourth and last is the loss of the possibility of objective evaluation of rationality in scientific methodology. It is argued that each of these problems is illusory. (shrink)

Constructive empiricism, the view introduced in The Scientific Image, is a view of science, an answer to the question "what is science?" Arthur Fine's and Paul Teller's contributions to this symposium challenge especially two key ideas required to formulate that view, namely the observable/unobservable and acceptance/belief distinctions. I wish to thank them not only for their insightful critique but also for the support they include. For they illuminate and counter some misunderstandings of Constructive Empiricism along the way. That leaves me (...) free to focus on those two main challenges. (shrink)

Thomason (1979/2010)'s argument against competence psychologism in semantics envisages a representation of a subject's competence as follows: he understands his own language in the sense that he can identify the semantic content of each of its sentences, which requires that the relation between expression and content be recursive. Then if the scientist constructs a theory that is meant to represent the body of the subject's beliefs, construed as assent to the content of the pertinent sentences, and that theory satisfies certain (...) 'natural assumptions', then it implies that the subject is inconsistent if the beliefs include arithmetic. I challenge the result by insisting that the motivation for Thomason's principle (ii), via Moore's Paradox, leads to a more complex representation, in which stating the facts and expressing one's beliefs are treated differently. Certain logical connections among expressions of assent, and between expression and statement, are a matter of consequence on pain of pragmatic incoherence, not consequence on pain of classical logical inconsistency. But while this salvages the possibility that a modification of the above sort of representation could be adequate, Thomason's devastating conclusion returns if the scientist identifies himself as the subject of that representation, even when paying heed to the requirement of pragmatic coherence of the sort highlighted by Moore's Paradox. (shrink)

In a traditional view of science we come to fully believe the main accepted theories . Some of the hypotheses "possible for all that science tells us" seem more likely than others: enter probability as grading the possibilities left open. Probabilism contends with this tradition. Richard Jeffrey told us never to resolve doubt but only to quantify it, and to give maximal probability only to tautologies. Despite severe difficulties, I shall argue that the traditional view is reconcilable with probabilism. I (...) will propose a single unified account with conditional personal probability as basic, allowing for full belief in empirical theories, with our probabilities grading the possibilities left open. (shrink)

What does it mean to embed the phenomena in an abstract structure? Or to represent them by doing so? The semantic view of theories runs into a severe problem if these notions are construed either naively, in a metaphysical way, or too closely on the pattern of the earlier syntactic view. Constructive empiricism and structural realism will then share those difficulties. The problem will be posed as in Reichenbach's The Theory of Relativity and A Priori Knowledge, and realist reactions will (...) be examined, but they will be argued to dissolve upon scrutiny. (shrink)

In recent papers Hans Halvorson has offered a critique of the semantic view of theories, showing that theories may be the same although the corresponding sets of models are different and, conversely, that theories may be different although the corresponding sets of models are the same. This critique will be assessed, first, as it pertains to issues concerning scientific models in the empirical sciences and, second, independent of any concern with empirical science.

Probabilism in epistemology does not have to be of the Bayesian variety. The probabilist represents a person''s opinion as a probability function; the Bayesian adds that rational change of opinion must take the form of conditionalizing on new evidence. I will argue that this is the correct procedure under certain special conditions. Those special conditions are important, and instantiated for example in scientific experimentation, but hardly universal. My argument will be related to the much maligned Reflection Principle (van Fraassen, (...) 1984, 1995), and partly inspired by the work of Brian Skyrms (1987). (shrink)