Alberto Cordero

According to an old way of thinking, any leve! of problematicity with respect to truth or theory dependence suffices to spoil the objectivity of a proposal. No credible discourse complies with such restrictions. Far from compromising the existence of knowledge, correct and incorrect, rational and nonrational ideas, however. the said old way of thinking is simply incapable of representing the cognitive achievements that we actually have. This paper discusses a contemporary way of approaching the difference between ideas of high and low descriptive quality in terms of epistemological criteria that prevail in the most rigorous and reliable scientific practices

The success of a scientific theory T is not an all-or-nothing matter; nor is a theory something one can usually accept or reject in toto (i.e. one may take T as being "approximately true", or take as true just certain "parts" of it, without necessarily affirming every posit and claim specific to T as being either completely right or completely wrong). This, however, raises questions about precisely which parts of T deserve to be taken as approximately true. on the basis of its success. A line of thinkers, particularly Kitcher, Leplin and Psillos, variously look for parts of a theory they can claim to have been "essentially" implicated in its distinctivesuccess, which they regard as primary candidates for realist truth ascription. But, how is one to determine which parts of any theory are "central" or "peripheral", "essential" or "idle" in the required sense? Attempts at spelling out relevant synchronic links between successful predictions and correct partial theorizing increasingly look like a misguided effort. As an alternative, this paper proposes a weaker, but arguably powerful enough, version of the realist relation between success and truth. Focusing on a pivotal case study in recent debates between realists and anti-realists (the conceptual changes undergone by theories oflight in the 19th century), a promising link between success and partial theoretical representation is located in the expansion and stabilization of approximately correct partial theoretical models of the theory's intended domain. The realist link is then formulated accordingly. In the resulting approach (a) predictive success is preserved as a marker of cumulative theoretical gain, but (b) specification of the latter is a diachronic rather than synchronic matter (i.e. gains become clear only after generations of theory change; specification of the particular loci of theoretical gain in connection with a given line of predictive success is not assumed to be generally possible at the time of the success in question). The truth ascriptions that get licensed are partial-of a piece-meal and retrospective sort, focused on methodologically specifiable theoretical subplots from past science.

Explanatory elucidation occurs when a theory has one or more of its assumptions explained by another independently successful theory. Because explanatory elucidation springs from independently supported theories, it improves the credibility of the assumptions it casts light on, hence its relevance for realists. But cases can be pointed to where explanatory elucidation has badly failed to identify truthful components. One way to address this challenge is by trying to find additional epistemic support for seemingly meritorious theory-parts. Resource in this regard, I suggest, include some specific lines of probing that regularly turn up against theories in mature scientific disciplines. Together with explanatory elucidation, those lines single out, in diachronic fashion, theory components worthy of realist commitment, or so I argue.

GRW models of the physical world are criticized in the literature for involving wave function "tails" that allegedly create fatal interpretive problems and even compromise standard arithmetic. I find such objections both unfair and misguided. But not all is well with the GRW approach. One complaint I articulate in this paper does not have to do with tails as such but with the specific way in which past physical structures linger forever in the total GRW wave function. By pushing the total proposal towards either the "Many Worlds" approach or the Bohmian approach, this feature diminishes extant GRW claims to preferability. I suggest, however, that the problem here is just an artifact of the particular and ultimately optional genre of collapse mechanism chosen by GRW

Recent attempts to turn Standard Quantum Theory into a coherent representational system have improved markedly over previous offerings. Important questions about the nature of material systems remain open, however, as current theorizing effectively resolves into a multiplicity of incompatible statements about the nature of physical systems. Specifically, the most cogent proposals to date land in effective empirical equivalence, reviving old anti-realist fears about quantum physics. In this paper such fears are discussed and found unsound. It is argued that nothing of global skeptical or agnostic significance follows from the kind of underdetermination presently encountered in fundamental quantum theory. The case is instructive, however, for what it shows about the characteristics and prospects of scientific realism as a perspective in contemporary philosophy of science.

Las interpretaciónes de la física cuántica de Everett-DeWitt hablan de una multiplicidad de mundos físicamente coexistenrtes. Éstas imaginativas reacciones a los problemas conceptuales de la mecánica cuántica estándar forman una família de propuestas de “universos múltiples” que, sin pleno éxito, han sido tachadas de incoherentes.Everett-DeWitt interpretations of quantum physics speak of a multiplicity of physically coexisting worlds. These imaginative reactions to the conceptual problems of standard quantum mechanics form a family of physicalist “many-worlds” proposals that have been variously dismissed as “incoherent”, so far without full success. A renewed charge by Hilary Putnam now seems to pose deeper trouble for PMW. In a recent paper, he seizes on “Schrödinger’s cat” situations to expose how PMW relativization of actuality and basic combinatorics jointly ruin probabilistic talk. Putnam focuses on confirmation and luck. His case against PMW is thought-provoking but also questionable, or so I suggest in this paper. First I argue that, as presented, Putnam’s charge doesn’t go through. I then consider his argument proper. According to Putnam, experimental DeWittians must count themselves as “lucky” in a seriously incoherent sense. I consider his take on “luck” and deny that defenders of PMW need to so regard themselves. Although extravagant, their position cannot be fruitfully dismissed as incoherent on metascientific grounds. Indeed it attests to the way science rationally helps the imagination to grow.

This paper examines some physical sources of the concept of objective state reduction in quantum mechanics. Using case studies from nuclear physics and quantum chemistry, the question of whether one can induce a collapse theory from the practices of scientists working on specific problems is considered. A specific proposal is explored, with emphasis on such features as coherence, testability, unifying power and fertility. It is shown that, contrary to recent suggestions by David Albert, collapse theories are philosophically promising developments worthy of further study. Some philosophical implications of the development of collapse theories are discussed

The success of a scientific theory T is not an all-or-nothing matter; nor is a theory something one can usually accept or reject in toto (i.e. one may take T as being "approximately true", or take as true just certain "parts" of it, without necessarily affirming every posit and claim specific to T as being either completely right or completely wrong). This, however, raises questions about precisely which parts of T deserve to be taken as approximately true. on the basis of its success. A line of thinkers, particularly Kitcher, Leplin and Psillos, variously look for parts of a theory they can claim to have been "essentially" implicated in its distinctivesuccess, which they regard as primary candidates for realist truth ascription. But, how is one to determine which parts of any theory are "central" or "peripheral", "essential" or "idle" in the required sense? Attempts at spelling out relevant synchronic links between successful predictions and correct partial theorizing increasingly look like a misguided effort. As an alternative, this paper proposes a weaker, but arguably powerful enough, version of the realist relation between success and truth. Focusing on a pivotal case study in recent debates between realists and anti-realists (the conceptual changes undergone by theories oflight in the 19th century), a promising link between success and partial theoretical representation is located in the expansion and stabilization of approximately correct partial theoretical models of the theory's intended domain. The realist link is then formulated accordingly. In the resulting approach (a) predictive success is preserved as a marker of cumulative theoretical gain, but (b) specification of the latter is a diachronic rather than synchronic matter (i.e. gains become clear only after generations of theory change; specification of the particular loci of theoretical gain in connection with a given line of predictive success is not assumed to be generally possible at the time of the success in question). The truth ascriptions that get licensed are partial-of a piece-meal and retrospective sort, focused on methodologically specifiable theoretical subplots from past science.