Various notions of plausibility are used in cognitive science to argue for or against the “goodness of theories.” However, plausibility remains poorly understood and difcult to analyze. We review debates in the philosophy of science on uses of plausibility in the assessment of novel scientifc theories as well as recent attempts to formalize, reform, or eliminate specifc notions of plausibility. Although these discussions highlight important concerns behind plausibility claims, they fail to identify viable notions of (...) plausibility that are sufciently diferent from other criteria of “good theory,” such as prior probability or external coherence. We survey uses of plausibility in linguistics and cognitive science, confrming that plausibility is often a proxy for other criteria of good theory. We argue that the need remains for concepts of plausibility that can be employed to assess the quality of proposals at the early stages of theory development when other criteria are not yet applicable. We identify two such notions: one relating to formal constraints on theories and another capturing initial epistemic consensus, if not necessarily convergence on the truth, about the target system in a community of inquiry. We briefy assess the specifcity and added value of these notions of plausibility relative to other criteria for good theory. (shrink)

In this article, I present a defense of conceptual plausibility, understood as an epistemic way to qualify concepts that situates them between the merely possible and the actual. To show that there is such a thing as conceptual plausibility, I rely on what seems to lie at the heart of many uses of the phrase “plausible concept”: explanatory fruitfulness. To make an effective case for the claim that conceptual plausibility is of philosophical interest, I present an argument (...) based on the debate over the rationality of theistic belief and the concept of God. To show that conceptual plausibility is philosophically feasible, I first show that it cannot be reduced to propositional plausibility. Next, I offer a minimally precise characterization of conceptual plausibility; I approach this from a qualitative and comparative perspective as well. Finally, I show how these qualitative and comparative criteria of conceptual plausibility might be applied to the debate over the rationality of theistic belief and the concept of God. (shrink)

Plausible Logic allows defeasible deduction with arbitrary propositions, and yet when sufficiently simplified it is very similar to the Defeasible Logics of Billington and Nute. This paper presents Plausible Logic, explains some of the ideas behind the definitions, applies Plausible Logic to an example, and proves a coherence result which indicates that Plausible Logic is well behaved. We also report the first complete implementation of propositional Plausible Logic. The implementation has a web interface which makes it available to researchers and (...) students everywhere. The implementation is evaluated experimentally, and is shown to be capable of handling tens of thousands of rules and sufficiently many disjunctions for realistic problems. (shrink)

Trust is a crucial component of the relationship between a professional and those whom the professional serves because those served often lack the past experience and specialized training necessary to adequately assess the reliability of the professional’s judgments on their behalf. This article is an attempt to enhance our understanding of the conditions under which client trust of a professional is plausible. Trust, I will explain, is an emotional attitude with a unique evaluative dimension that can lead the one who (...) trusts to anticipate that the one trusted will not betray her even when she cannot adequately assess evidence of the trusted’s reliability. It is, however, precisely because evaluating someone’s trustworthiness differs in important respects from assessing their reliability that substantive trust of a professional is implausible in cases where those served by a particular profession, for example, medicine or journalism, conceive of it as merely a commercial enterprise. (shrink)

Although, when first introduced, Copernicus's theory considered as a whole was not superior to the Ptolemaic theory according to any of the usual criteria for comparing theories and determining their acceptability, it did have features which provided the early Copernicans with good reasons for entertaining it and trying to develop it further. These features are discussed and then three plausibility considerations which seem to be operative in this case are formulated.

In this article, a qualitative notion of subjective plausibility and its revision based on a preorder relation are implemented in higher-order logic. This notion of plausibility is used for modeling pragmatic aspects of communication on top of traditional two-dimensional semantic representations.

The analytic tradition of thought in the West started in the late nineteenth century with what is known as ‘linguistic turn’ in philosophy. But as a methodological movement, it impacted other areas of knowledge as well. Feminist scholars react to the analytic tradition of thought in many various ways. Many of them critique and challenge the tradition. The present paper aims at a review of a feminist take on Sigmund Freud who imported analytical tradition in psychology at the beginning of (...) the twentieth century. Luce Irigaray questions the legitimacy of Freudian analysis and challenges the claim of neutrality of Freudian discourse by accusing that Freud works within a patriarchal-biased ideology. About the logical basis of Freudian discourse, Irigaray alleges that a logic of indifference is at work there. But how far has Irigaray, as a feminist, been successful in showing the biases and loopholes in Freudian discourse? This paper attempts to show that the Irigarayian line of argument and critique of Freud does not offer a stronger and plausible feminist stance. (shrink)

Homeopathy is controversial and hotly debated. The conclusions of systematic reviews of randomised controlled trials of homeopathy vary from ‘comparable to conventional medicine’ to ‘no evidence of effects beyond placebo’. It is claimed that homeopathy conflicts with scientific laws and that homoeopaths reject the naturalistic outlook, but no evidence has been cited. We are homeopathic physicians and researchers who do not reject the scientific outlook; we believe that examination of the prior beliefs underlying this enduring stand-off can advance the debate. (...) We show that interpretations of the same set of evidence—for homeopathy and for conventional medicine—can diverge. Prior disbelief in homeopathy is rooted in the perceived implausibility of any conceivable mechanism of action. Using the ‘crossword analogy’, we demonstrate that plausibility bias impedes assessment of the clinical evidence. Sweeping statements about the scientific impossibility of homeopathy are themselves unscientific: scientific statements must be precise and testable. There is growing evidence that homeopathic preparations can exert biological effects; due consideration of such research would reduce the influence of prior beliefs on the assessment of systematic review evidence. (shrink)

Human decisions are conditioned by formidable uncertainty. The standard resource for dealing rationally with uncertainty is the mathematical concept of probability. The probability calculus is well-known, but since the numerical demands for applying it cannot usually be met, it is not widely applicable. By contrast, the concept of plausibility is widely applicable, but it is little known. This book relies on a generalized concept of plausibility whose strength is its adaptability. The adaptability is due to a novel form (...) of decision theory that takes plausibilities as inputs. This form of decision theory can be adapted to decisions informed by sharp probabilities and utilities as well as to decisions that must be made without them. The book illustrates its application to problems in argumentation theory, scientific theory choice, risk management, ethics, law, economics, and epistemology. (shrink)

Counterfactual thinking involves imagining hypothetical alternatives to reality. Philosopher David Lewis argued that people estimate the subjective plausibility that a counterfactual event might have occurred by comparing an imagined possible world in which the counterfactual statement is true against the current, actual world in which the counterfactual statement is false. Accordingly, counterfactuals considered to be true in possible worlds comparatively more similar to ours are judged as more plausible than counterfactuals deemed true in possible worlds comparatively less similar. Although (...) Lewis did not originally develop his notion of comparative similarity to be investigated as a psychological construct, this study builds upon his idea to empirically investigate comparative similarity as a possible psychological strategy for evaluating the perceived plausibility of counterfactual events. More specifically, we evaluate judgments of comparative similarity between episodic memories and episodic counterfactual events as a factor influencing people's judgments of plausibility in counterfactual simulations, and we also compare it against other factors thought to influence judgments of counterfactual plausibility, such as ease of simulation and prior simulation. Our results suggest that the greater the perceived similarity between the original memory and the episodic counterfactual event, the greater the perceived plausibility that the counterfactual event might have occurred. While similarity between actual and counterfactual events, ease of imagining, and prior simulation of the counterfactual event were all significantly related to counterfactual plausibility, comparative similarity best captured the variance in ratings of counterfactual plausibility. Implications for existing theories on the determinants of counterfactual plausibility are discussed. (shrink)

The national-level scenarios project NanoFutures focuses on the social, political, economic, and ethical implications of nanotechnology, and is initiated by the Center for Nanotechnology in Society at Arizona State University (CNS-ASU). The project involves novel methods for the development of plausible visions of nanotechnology-enabled futures, elucidates public preferences for various alternatives, and, using such preferences, helps refine future visions for research and outreach. In doing so, the NanoFutures project aims to address a central question: how to deliberate the social implications (...) of an emergent technology whose outcomes are not known. The solution pursued by the NanoFutures project is twofold. First, NanoFutures limits speculation about the technology to plausible visions. This ambition introduces a host of concerns about the limits of prediction, the nature of plausibility, and how to establish plausibility. Second, it subjects these visions to democratic assessment by a range of stakeholders, thus raising methodological questions as to who are relevant stakeholders and how to activate different communities so as to engage the far future. This article makes the dilemmas posed by decisions about such methodological issues transparent and therefore articulates the role of plausibility in anticipatory governance. (shrink)

In this paper we argue that in recent literature on mechanistic explanations, authors tend to conflate two distinct features that mechanistic models can have or fail to have: plausibility and richness. By plausibility, we mean the probability that a model is correct in the assertions it makes regarding the parts and operations of the mechanism, i.e., that the model is correct as a description of the actual mechanism. By richness, we mean the amount of detail the model gives (...) about the actual mechanism. First, we argue that there is at least a conceptual reason to keep these two features distinct, since they can vary independently from each other: models can be highly plausible while providing almost no details, while they can also be highly detailed but plainly wrong. Next, focusing on Craver's continuum of ?how-possibly,? to ?how-plausibly,? to ?how-actually? models, we argue that the conflation of plausibility and richness is harmful to the discussion because it leads to the view that both are necessary for a model to have explanatory power, while in fact, richness is only so with respect to a mechanism's activities, not its entities. This point is illustrated with two examples of functional models. (shrink)

Homeopathy is controversial and hotly debated. The conclusions of systematic reviews of randomised controlled trials of homeopathy vary from ‘comparable to conventional medicine’ to ‘no evidence of effects beyond placebo’. It is claimed that homeopathy conflicts with scientific laws and that homoeopaths reject the naturalistic outlook, but no evidence has been cited. We are homeopathic physicians and researchers who do not reject the scientific outlook; we believe that examination of the prior beliefs underlying this enduring stand-off can advance the debate. (...) We show that interpretations of the same set of evidence—for homeopathy and for conventional medicine—can diverge. Prior disbelief in homeopathy is rooted in the perceived implausibility of any conceivable mechanism of action. Using the ‘crossword analogy’, we demonstrate that plausibility bias impedes assessment of the clinical evidence. Sweeping statements about the scientific impossibility of homeopathy are themselves unscientific: scientific statements must be precise and testable. There is growing evidence that homeopathic preparations can exert biological effects; due consideration of such research would reduce the influence of prior beliefs on the assessment of systematic review evidence. (shrink)

In qualitative decision theory, a very natural way for defining preference relations over policies (acts) -functions from a set S of states to a set X of consequences- is by using the so called Dominance Plausible Rule. In this context we need a relation > over X and a relation ? over P(S) (the subsets of S). Then we define ≥ as follows: f ≥ g, ? [f > g] ? [g > f], where [f > g] denotes the set (...) {s ? S : f(s) > g(s)g}. In many cases > is a modular relation and ? is a total preorder. A quite rational and desirable property for the relation over policies is transitivity. In general, the relation ≥ defined by the Dominance Plausible Rule is not transitive in spite of the transitivity of ?. In this work we characterize the properties of the relation ? forcing the relation ≥ over policies to be transitive. All this under the hypothesis of modularity of the relation >. (shrink)

Judgments of plausibility involve appearance of the truth or reasonableness, which is always a function of background knowledge. What anyone will countenance is conditioned by what they already know (or think they know). Marc Kirschner (professor of systems biology at Harvard) and John Gerhart (professor of molecular and cell biology at the University of California—Berkeley) aim to show that molecular, cellular, and developmental processes relevant to the generation of phenotypic variation in anatomy, physiology, and behavior demonstrate how evolutionary processes, (...) especially the origins of novelty, are plausible. The outstanding question for Kirschner and Gerhart concerns not the modification of structures but their origination—a question unanswered by the theoretical framework of the modern synthesis. (shrink)

Satisficing without thereby maximizing is rational provided that non-consequentialism is rational and provided that the preferred characterization of non-consequentialism is not one in which right action is justified in virtue of maximizing agent-relative value. Rather, the non-consequentialism which can serve to defend satisficing should be one in which the best characterization of certain reasons to act does not involve maximization of value of any sort, whether agent-relative or agent neutral. I argue there are reasons to prefer this sort of non-consequentialism (...) to theories which defend non-consequentialism by construing value as agent-relative. An upshot is that satisficing cannot be well-defended within an overall consequentialist framework. (shrink)

Mental fatigue can be studied by using either the time-on-task protocol or the sequential task protocol. In the time-on-task protocol, participants perform a long and effortful task and a decrease in performance in this task is generally observed over time. In the sequential task protocol, a first effortful or control task is followed by a second effortful task. The performance in the second task is generally worse after the effortful task than after the control task. The principal aim of the (...) present experiment is to examine the relationship between these two decrements in performance while concomitantly using a sequential task protocol and assessing the performance of the first effortful task as a function of time-on-task. We expect a positive correlation between these two decrements in performance. A total of 83 participants performed a 30-min fatiguing mental task or a control task followed by a time-to-exhaustion handgrip task. As expected, this protocol combining the time-on-task and sequential task protocols allowed us to observe a decrease in performance over time during the Stroop task, a worst performance in the handgrip task after the Stroop task by comparison to the control task, a positive correlation between these two effects. The decrease in performance during the Stroop task also correlated with the subjective measures of boredom and fatigue, whereas the detrimental effect observed in the handgrip task did not. Our findings suggest that the two fatigue-related phenomena share a common mechanism but are not completely equivalent. (shrink)

This book provides a practical and accessible way of evaluating good and bad arguments used in everyday conversations by applying normative models of dialectical (interactive) argumentation, where two parties reason together in an orderly and cooperative way. Using case studies, the author analyzes correct and incorrect uses of argumentation on controversial issues that engage the reader's interest while illustrating points in a practical way. Walton gives clear explanations of the most common errors and tricky deceptions -- traditionally called "fallacies" -- (...) that can trip up an unwary arguer. (shrink)

In this chapter I defend a methodological view about how we should conduct substantive ethical inquiries in the fields of normative and practical ethics. I maintain that the direct plausibility and implausibility of general ethical principles – once fully clarified and understood – should be foundational in our substantive ethical reasoning. I argue that, in order to expose our ethical intuitions about particular cases to maximal critical scrutiny, we must determine whether they can be justified by directly plausible principles. (...) To expose apparently plausible principles to maximal critical scrutiny, we must determine whether their direct plausibility can survive careful clarification of what they are really saying. This means that intuitions about cases are useful only in (a) suggesting principles that must stand on their own two feet, and (b) illustrating or otherwise helping us clarify what a principle is really saying. We should not reject principles that seem most directly plausible after we have fully clarified their content simply because they conflict with our intuitions about cases, because to do so is to side with uncritical prejudices over the teachings of critical scrutiny. (shrink)

Falk's hypothesis is attractive and seems to be supported by data from primatology and language acquisition literature. However, this etiological narrative presents a fairly low degree of plausibility, the result of two epistemological fallacies: an implicit reliance on a unilinear model of causality and the explicit belief that ontogeny is homologous to phylogeny. Although this attempt to retrace the early emergence of prelinguistic capacities in hominins falls short of producing a compelling argument, it does call attention to an aspect (...) of linguistic behavior which may indeed have evolved under the pressure of nurturing constraints. (shrink)

The United States Supreme Court's decision in Bell Atlantic Corp. v. Twombly is creating quite a stir. Suddenly gone is the famous loosey-goosey rule of Conley v. Gibson that a complaint should not be dismissed for failure to state a claim unless it appears beyond doubt that the plaintiff can prove no set of facts in support of his claim which would entitle him to relief.Now a complaint must provide enough facts to state a claim to relief that is plausible (...) on its face. Only decided last May, Bell Atlantic has been cited in over 3,700 cases. Already being described as a landmark decision, Bell Atlantic nonetheless has lawyers and judges scratching their heads over the precise pleading standard to apply in its wake. As the Second Circuit (mildly) put it, Considerable uncertainty concerning the standard for assessing the adequacy of pleadings has recently been created by the Supreme Court's decision in Bell Atlantic Corp. v. Twombly. Just what is a plausible showing that the pleader is entitled to relief under Rule 8(a)(2)?I believe an answer lies in the 26-year-old decision of the Former Fifth Circuit in In re Plywood Antitrust Litigation. Plywood Antitrust requires, at a minimum, that a complaint . . . contain either direct or inferential allegations respecting all the material elements necessary to sustain a recovery under some viable legal theory. Already used in more than half the circuits, this standard paraphrases advice found in the venerable WRIGHT & MILLER for nearly 40 years.Properly applied, this all . . . material elements standard satisfies Bell Atlantic's plausibility requirement in all respects. The Plywood Antitrust pleading standard works well after Bell Atlantic, first, because the Supreme Court referred to the standard, albeit parenthetically, with approval in Bell Atlantic. Second, it does much to harmonize the Federal Rules' goal of dispensing with pleading technicalities while still requiring enough general factual information about a pleader's claim to make the notice in notice pleading meaningful. Finally, and perhaps most importantly, it gives lawyers, litigants, and courts a standard they can actually use when drafting, or assessing the sufficiency of, pleadings. (shrink)

Possibilities haunt history. The force of our explanations of events turns on the alternative possibilities these explanations suggest. It is these possible worlds which give us our understanding; and in human affairs we decide them by practical rather than theoretical judgement. In his widely acclaimed account of the role of counterfactuals in explanation, Geoffrey Hawthorn deploys extended examples from history and modern times to defend his argument. His conclusions cast doubt on existing assumptions about the nature and place of theory, (...) and indeed of the possibility of knowledge itself, in the human sciences. (shrink)

Underdetermination of theory choice claims that empirical evidence fails to provide sufficient grounds for choosing a theory over its rivals. We explore the epistemological and methodological significance of this thesis by utilising a classificatory scheme to situate three arguments that purport to establish its plausibility. Proponents of these three arguments, W.V.O Quine, John Earman, and Kyle Stanford, use different premises to arrive at the conclusion that theory choice is empirically underdetermined and their classification along the proposed schema brings out (...) the variety in underdetermination arguments and the historical trajectory of the thesis. Although the epistemological significance of underdetermination—it is seen as undermining the doctrine of scientific realism—is widely discussed in the literature, Quine understood the acceptance of the thesis as interrogating the attitude one is justified in adopting towards rival theories. We argue that sticking with one’s own theory in the face of underdetermination leads to a distinct type of disagreement, which we present as the methodological significance of underdetermination. The examination of the methodological significance of underdetermination allows us to propose weak underdetermination as a philosophically interesting variant of underdetermination. (shrink)

The manipulation argument poses a significant challenge for any adequate compatibilist theory of agency. The argument maintains that there is no relevant difference between actions or pro‐attitudes that are induced by nefarious neurosurgeons, God, or (and this is the important point) natural causes. Therefore, if manipulation is thought to undermine moral responsibility, then so also ought causal determinism. In this paper, I will attempt to bolster the plausibility of John Martin Fischer and Mark Ravizza's semicompatibilist theory of moral responsibility (...) by demonstrating how their account provides a distinctive line of response to three important types of manipulation. (shrink)

The cardinality of incompatible possibilities whose actuality requires at least N seconds exceeds the cardinality of disjoint intervals at least N seconds long. Therefore, not all logical possibilities can be actual in the long run, even if the long run is infinite.

Abstract. Richard Feldman’s Uniqueness Thesis holds that “a body of evidence justifies at most one proposition out of a competing set of proposi- tions”. The opposing position, permissivism, allows distinct rational agents to adopt differing attitudes towards a proposition given the same body of evidence. We assess various motivations that have been offered for Uniqueness, including: concerns about achieving consensus, a strong form of evidentialism, worries about epistemically arbitrary influences on belief, a focus on truth-conduciveness, and consequences for peer disagreement. (...) We argue that each of these motivations either misunderstands the commitments of permissivism or is question-begging. Better understanding permissivism makes it a much more plausible position. (shrink)

We present a simple propositional proof system which consists of a single axiom schema and a single rule, and use this system to construct a sequence of combinatorial tautologies that, when added to any Frege system, p-simulates extended-Frege systems.

This paper provides an analysis of the cognitive processes implied in the ego defense known as projection. Projection is first placed in the context of the general cognitive processes of attribution and ascription. Then we address defensive projection, and identify its distinctive features. In particular, whereas general projection consists in the ascription of one's own mental attitudes to others, defensive projection implies one's rejection of the ascribed mental states, and ascription is a means for supporting this rejection. We try to (...) understand how and why ascription is functional to rejection. Then, we examine a few types of defensive projection, and identify the main components and steps in the projective process. Finally, we draw some general conclusions. (shrink)

Several approaches to implementing symbol-like representations in neurally plausible models have been proposed. These approaches include binding through synchrony, “mesh” binding, and conjunctive binding. Recent theoretical work has suggested that most of these methods will not scale well, that is, that they cannot encode structured representations using any of the tens of thousands of terms in the adult lexicon without making implausible resource assumptions. Here, we empirically demonstrate that the biologically plausible structured representations employed in the Semantic Pointer Architecture approach (...) to modeling cognition do scale appropriately. Specifically, we construct a spiking neural network of about 2.5 million neurons that employs semantic pointers to successfully encode and decode the main lexical relations in WordNet, which has over 100,000 terms. In addition, we show that the same representations can be employed to construct recursively structured sentences consisting of arbitrary WordNet concepts, while preserving the original lexical structure. We argue that these results suggest that semantic pointers are uniquely well-suited to providing a biologically plausible account of the structured representations that underwrite human cognition. (shrink)

The plausible reasoning class (called the JSM-reasoning in honour of John Stuart Mill) is described. It implements interaction of three forms of non-deductive procedures  induction, analogy and abduction. Empirical induction in the JSM-reasoning is the basis for generation of hypotheses on causal relations (determinants of social behaviour). Inference by analogy means that predictions about previously unknown properties of objects (individual’s behaviour) are inferred from causal relations. Abductive inference is performed to check on the explanatory adequacy of generated hypotheses. To (...) recognize rationality of respondents’ opinion deductive inference is used. Plausible reasoning, semantics of argumentation logic and deductive recognition of opinion rationality represent logical tool for cognitive sociology problems. (shrink)

The identification of plausible epistemic approaches in science as well as the social problem definitions with which scientists implicitly work is essential for the quality of a deliberative public policy. While responding to the Nanofutures project, I will reflect on the essential elements of such a policy.

In this paper, we examine some issues debated in mainstream epistemology for which the social features of knowledge are relevant, such as the epistemic relevance of social contexts, the nature of practical knowledge, and the epistemic role of testimony. In the first part of the paper, we show how feminist epistemologies have usefully stressed the social character of knowledge in many central areas of debate within mainstream epistemology. We call these the virtues of feminist epistemology: the denial of the neutrality (...) and autonomy of the epistemic subject, the focus on practical knowledge, and the ensuing attention to the social dimensions of the epistemic process. Our conclusion on the social dimensions of knowledge is the thesis that the epistemic subject can know only in connection with others. In the second part of the paper, we address the issue of the plausibility of feminist epistemologies by discussing three main criticisms which have been raised against them. We conclude that, even if these criticisms are valid, the legacy of feminist epistemologies remains because the social features of knowledge are plausibly significant not only within but also without the perspectives of feminist epistemologies. (shrink)

Events that violate the laws of nature are, by definition, impossible, but recent research suggests that people view some violations as “more impossible” than others. When evaluating the difficulty of magic spells, American adults are influenced by causal considerations that should be irrelevant given the spell’s primary causal violation, judging, for instance, that it would be more difficult to levitate a bowling ball than a basketball even though weight should no longer be a consideration if contact is no longer necessary (...) for support. In the present study, we sought to test the generalizability of these effects in a non-Western context – China – where magical events are represented differently in popular fiction and where reasoning styles are often more holistic than analytic. Across several studies, Chinese adults showed the same tendency as American adults to honor implicit causal constraints when evaluating the plausibility of magical events. These findings suggest that graded notions of impossibility are shared across cultures, possibly because they are a byproduct of causal knowledge. (shrink)