Putnam,realism and truth

There are several distinct components of the realist anti-realist debate. Since each side in the debate has its disadvantages, it is tempting to try to combine realist theses with anti-realist theses in order to obtain a better, more moderate position. Putnam attempts to hold a realist concept of truth, yet he rejects realist metaphysics and realist semantics. He calls this view internal realism. Truth is realist on this picture for it is objective, rather than merely intersubjective, and eternal. Putnam introduces a concept of epistemic idealization — epistemically ideal conditions, or idealized justification — to try to ground the strong objectivity of truth without sliding into metaphysical realism. I argue that the concept of ideal conditions to which Putnam appeals does not cohere with his (anti-realist) commitment to an assertability conditions account of meaning.     

Structural correspondence,indirect reference,and partial truth: phlogiston theory and Newtonian mechanics

This paper utilizes a logical correspondence theorem (which has been proved elsewhere) for the justification of weak conceptions of scientific realism and convergence to truth which do not presuppose Putnam’s no-miracles-argument (NMA). After presenting arguments against the reliability of the unrestricted NMA in Sect. 1, the correspondence theorem is explained in Sect. 2. In Sect. 3, historical illustrations of the correspondence theorem are given, and its ontological consequences are worked out. Based on the transitivity of the concept of correspondence, a correspondence-based notion of convergence to truth is developed in Sect. 4. In the final Sect. 5 it is argued that the correspondence theorem together with the assumption of ‘minimal realism’ yields a justification of a weak version of scientific realism, which is then compared to metaphysical realism and to instrumentalism.     

The sad truth about depressive realism

In one form of a contingency judgement task individuals must judge the relationship between an action and an outcome. There are reports that depressed individuals are more accurate than are nondepressed individuals in this task. In particular, nondepressed individuals are influenced by manipulations that affect the salience of the outcome, especially outcome probability. They overestimate a contingency if the probability of an outcome is high—the “outcome-density effect”. In contrast, depressed individuals display little or no outcome-density effect. This apparent knack for depressives not to be misled by outcome density in their contingency judgements has been termed “depressive realism”, and the absence of an outcome-density effect has led to the characterization of depressives as “sadder but wiser”. We present a critical summary of the depressive realism literature and provide a novel interpretation of the phenomenon. We suggest that depressive realism may be understood from a psychophysical analysis of contingency judgements.*     

Correspondence truth and scientific realism

I argue that one good reason for Scientific Realists to be interested in correspondence theories is the hope they offer us of being able to state and defend realistic theses in the face of well-known difficulties about modern physics: such theses as, that our theories are approximately true, or that they will tend to approach the truth. I go on to claim that this hope is unlikely to be fulfilled. I suggest that Realism can still survive in the face of these difficulties, as a claim about the kind of theories we want to aim for. I relate this conception of Realism to various contemporary discussions, both by realists and antirealists.     

The problem of properties in quantum mechanics

The properties of classical and quantum systems are characterized by different algebraic structures. We know that the properties of a quantum mechanical system form a partial Boolean algebra not embeddable into a Boolean algebra, and so cannot all be co-determinate. We also know that maximal Boolean subalgebras of properties can be (separately) co-determinate. Are there larger subsets of properties that can be co-determinate without contradiction? Following an analysis of Bohrs response to the Einstein-Podolsky-Rosen objection to the complementarity interpretation of quantum mechanics, a principled argument is developed justifying the selection of particular subsets of properties as co-determinate for a quantum system in particular physical contexts. These subsets are generated by sets of maximal Boolean subalgebras, defined in each case by the relation between the quantum state and a measurement (possibly, but not necessarily, the measurement in terms of which we seek to establish whether or not a particular property of the system in question obtains). If we are required to interpret quantum mechanics in this way, then predication for quantum systems is quite unlike the corresponding notion for classical systems.     

Test of the violation of local realism in quantum mechanics with no use of Bell's inequalities

A novel and versatile polarization-entanglement scheme is adopted to investigate the violation of the EPR local realism for a non-maximally entangled two-photon system according to the recent nonlocality proof by Lucien Hardy. In this context the adoption of a sophisticated detection method allows direct determination of any element of physical reality (viz., determined with probability equal to unity in the words of Einstein, Podolsky and Rosen) for the pair system within complete measurements that are largely insensitive to the detector quantum-efficiencies and noise.     

Agnostic empiricism versus scientific realism: Belief in truth matters

This paper aims to defend scientific realism against two versions of agnostic empiricism: a naive agnostic position, which suggests that the only rational option is to remain agnostic as to the truth of theoretical assertions, and van Fraassen's more sophisticated agnostic empiricism - which may be called "Hypercritical Empiricism". It first argues that given semantic realism, naive agnostic empiricism cannot be maintained: there is no relevant epistemic difference between theoretical assertions and observational ones. It then focuses on van Fraassen's more sophisticated alternative to scientific realism and suggests that an attitude towards science which involves less than aiming at theoretical truth and believing in theories would be, in some concrete respect that empiricists should recognize, worse off than the recommended realist attitude. To this end, the paper develops the so-called conjunction argument into a diachronic argument for scientific realism.     

The integration problem for naive realism

This paper makes explicit the basic problem perfect hallucinations pose for perceptual naive realists, more fundamental than the well-trodden Screening-off Problem. The deeper problem offers the basis for an overarching classification of the available naive- realist-friendly approaches to perfect hallucinations. In the course of laying out the challenges to the different types of response, the paper makes a case for the superiority of a particular approach to perfect hallucinations, on which they would be understood as a special kind of perceptual anomaly—arising from a secondary mode of perceptual processing.     

The effects of realism on Wason's THOG problem

Summary In this series of experiments the effects of phrasing Wason's THOG problem in realistic terms were investigated. Experiments 1 and 2 used realistic materials of very different kinds, but neither version of the problem produced any facilitation compared with the original abstract version. Experiment 3 used a version of the problem in which the correct answer was cued in by the realistic material, and a significant improvement was found. Experiment 4 used a version of the problem similar to that used in Experiment 3 and again improved performance was found; since the subjects in this experiment were eight- and nine-year-old children, the facilitation almost certainly was not the result of improved logical ability. The results of Experiment 5, however, suggested that it was difficult to cue in adults to give the logically incorrect answer. It is concluded that realism improves performance on this problem only when the realistic material cues in the correct answer from memory. A review of the research that makes use of other reasoning paradigms suggests that this conclusion may hold true for these as well.     

Success and truth in the realism/anti-realism debate

I aim to clarify the relationship between the success of a theory and the truth of that theory. This has been a central issue in the debates between realists and anti-realists. Realists assume that success is a reliable indicator of truth, but the details about the respects in which success is a reliable indicator or test of truth have been largely left to our intuitions. Lewis (Synthese 129:371–380, 2001) provides a clear proposal of how success and truth might be connected, comparing a test of success of our theories to medical tests with low rates of false positives and false negatives. But, contrary to what Lewis claims, I argue that it is not enough for the realist to undercut the claim that success is not a reliable indicator of truth. Rather, the realist must show that our current best theories are likely true. Further, I argue that tests in science are unlike medical tests in a number of important ways.     

Time,quantum mechanics,and decoherence

State-reduction and the notion of actuality are compared to passage through time and the notion of the present; already in classical relativity the latter give rise to difficulties. The solution proposed here is to treat both tense and value-definiteness as relational properties or facts as relations; likewise the notions of change and probability. In both cases essential characteristics are absent: temporal relations are tenselessly true; probabilistic relations are deterministically true.The basic ideas go back to Everett, although the technical development makes use of the decoherent histories theory of Griffiths, Omnès, and Gell-Mann and Hartle. Alternative interpretations of the decoherent histories framework are also considered.I would like to thank Abner Shimony for valuable criticism.     

Time,quantum mechanics,and tense

The relational approach to tense holds that “the now”, “passage”, and “becoming” are to be understood in terms of relations between events. The debate over the adequacy of this framework is illustrated by a comparative study of the sense in which physical theories, (in)deterministic and (non)relativistic, can lend expression to the metaphysics at issue. The objective is not to settle the matter, but to clarify the nature of this metaphysics and to establish that the same issues are at stake in the relational approach to value-definiteness and probability in quantum mechanics. They concern the existence of a unique present, respectively actuality, and a notion of identity over time that cannot be paraphrased in terms of relations.     

Systematicity theory meets Socratic scientific realism: the systematic quest for truth

Synthese - Systematicity theory—developed and articulated by Paul Hoyningen-Huene—and scientific realism constitute separate encompassing and empirical accounts of the nature of...     

The foundations of probability and quantum mechanics

Taking as starting point two familiar interpretations of probability, we develop these in a perhaps unfamiliar way to arrive ultimately at an improbable claim concerning the proper axiomatization of probability theory: the domain of definition of a point-valued probability distribution is an orthomodular partially ordered set. Similar claims have been made in the light of quantum mechanics but here the motivation is intrinsically probabilistic. This being so the main task is to investigate what light, if any, this sheds on quantum mechanics. In particular it is important to know under what conditions these point-valued distributions can be thought of as derived from distribution-pairs of upper and lower probabilities on boolean algebras. Generalising known results this investigation unsurprisingly proves unrewarding. In the light of this failure the next topic investigated is how these generalized probability distributions are to be interpreted.     

On truth and reference in postmodern science

Abstract:

If the defenders of typical postmodem accounts of science (and their less extreme social-constructivist partners) are at one end of the scale in current philosophy of science, who shall we place at the other end? Old-style metaphysical realists? Neo-neo-positivists? … Are the choices concerning realist issues as simple as being centered around either, on the one hand, whether it is the way reality is “constructed” in accordance with some contingent language game that determines scientific “truth”; or, on the other hand, whether it is the way things are in an independent reality that makes our theories true or false? If, in terms of realism, “strong” implies “metaphysical” in the traditional sense, and “weak” implies “non-absolutist” or “non-unique”, what - if anything - could realism after Rorty’s shattering of the mirror of nature still entail? In accordance with my position as a model-theoretic realist, I shall show in this article the relevance of the assumption of an independent reality for postmodern (philosophy of) science - against Lyotard’s dismissal of the necessity of this assumption for science which he interprets as a non-privileged game among many others. I shall imply that science is neither the “child” of positivist philosophy who has outgrown her mother, freeing herself from metaphysics and epistemology, nor is science, at the other end of the scale, foundationless and up for grabs.