People frequently gesture when problem-solving, particularly on tasks that require spatial transformation. Gesture often facilitates task performance by interacting with internal mental representations, but how this process works is not well understood. We investigated this question by exploring the case of mental abacus, a technique in which users not only imagine moving beads on an abacus to compute sums, but also produce movements in gestures that accompany the calculations. Because the content of MA is transparent and readily manipulated, the task (...) offers a unique window onto how gestures interface with mental representations. We find that the size and number of MA gestures reflect the length and difficulty of math problems. Also, by selectively interfering with aspects of gesture, we find that participants perform significantly worse on MA under motor interference, but that perceptual feedback is not critical for success on the task. We conclude that premotor processes involved in the planning of gestures are critical to mental representation in MA. (shrink)

The psycholinguistic literature has identified two syntactic adaptation effects in language production: rapidly decaying short-term priming and long-lasting adaptation. To explain both effects, we present an ACT-R model of syntactic priming based on a wide-coverage, lexicalized syntactic theory that explains priming as facilitation of lexical access. In this model, two well-established ACT-R mechanisms, base-level learning and spreading activation, account for long-term adaptation and short-term priming, respectively. Our model simulates incremental language production and in a series of modeling studies, we show (...) that it accounts for (a) the inverse frequency interaction; (b) the absence of a decay in long-term priming; and (c) the cumulativity of long-term adaptation. The model also explains the lexical boost effect and the fact that it only applies to short-term priming. We also present corpus data that verify a prediction of the model, that is, that the lexical boost affects all lexical material, rather than just heads. (shrink)

Is conceptual analysis required for reductive explanation? If there is no a priori entailment from microphysical truths to phenomenal truths, does reductive explanation of the phenomenal fail? We say yes . Ned Block and Robert Stalnaker say no.

This paper offers a probabilistic treatment of the conditions for argument cogency as endorsed in informal logic: acceptability, relevance, and sufficiency. Treating a natural language argument as a reason-claim-complex, our analysis identifies content features of defeasible argument on which the RSA conditions depend, namely: change in the commitment to the reason, the reason’s sensitivity and selectivity to the claim, one’s prior commitment to the claim, and the contextually determined thresholds of acceptability for reasons and for claims. Results contrast with, and (...) may indeed serve to correct, the informal understanding and applications of the RSA criteria concerning their conceptual dependence, their function as update-thresholds, and their status as obligatory rather than permissive norms, but also show how these formal and informal normative approachs can in fact align. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy and Rhetoric 36.3 (2003) 177-188 [Access article in PDF] Chaïm Perelman's "First Philosophies and Regressive Philosophy":Commentary and Translation David A. Frank Michelle K. Bolduc Chaïm Perelman's 1949 article, "First Philosophies and Regressive Philosophy," has remained unavailable to readers unable to read French. Our commentary and translation is intended to provide English readers access to the context, influences, and themes that make the article an extraordinarily important (...) work in the history of twentieth-century rhetoric. In this article, Perelman offers a powerful critique of first philosophies and anticipates the problems of radical postmodernity. "First Philosophies" remains a strikingly elegant attempt to foil what Foucault (1984, 41-42) has called the "Enlightenment blackmail of reason," the assumption held by logical positivists and radical skeptics that if reason does not yield absolute and eternal Enlightenment knowledge, there can be no knowledge.Perelman and Lucie Olbrechts-Tyteca's New Rhetoric project avoids Enlightenment blackmail by charting a third way between logical positivism and radical relativism, and "First Philosophies" sets forth the project's philosophical blueprint. Commencing in 1947 and culminating in 1958 with the publication of Traité de l'argumentation: La nouvelle rhétorique, Perelman and Olbrechts-Tyteca sought, discovered, and developed a philosophical system designed as a rapprochement between dialectic (reason and logic) and rhetoric (the art of adapting arguments to audiences). Historians of rhetoric judge the work a "grand revolution" (Meyer 1999, 259), believing it marks a rhetorical renaissance in Europe, and suggest nothing like it will appear for another 100 years after its publication (Johnstone 1971). The New Rhetoric project influenced Gadamer and a host of post-war European and American thinkers (Mootz 1998). Michael Leff calls the 1970 English translation of Traité a "bombshell" (1994, 510). Beyond its historical importance, Crosswhite suggests that the New Rhetoric project is "the single most important event in contemporary rhetorical theory" (1996, 35)and "First Philosophies" marks Perelman's turn from logical [End Page 177] positivism to rhetoric, offering prescient answers to the post-World War II crises of reason, and the ideas in the article provide the Traité'sphilosophical glue (see in particular the English translation, 62).Perelman joined many post-war theorists, including Horkheimer and Adorno (1972), in the resistance to the reign of a disembodied Enlightenment rationality. However, Perelman identified what Habermas (1987, 119) would later call the "performative contradiction" in the conclusion that radical skepticism was the only alternative to Enlightenment rationality. In "First Philosophies," Perelman responds directly to Sartre's 1943 Being and Nothingness (198; see translation below) by exposing the failure of radical skeptics to see that they had been held hostage by Enlightenment blackmail in accepting the Enlightenment criterion for truth, rejecting it, and then making skepticism an absolute. Indeed, "First Philosophies" navigates from this performative contradiction to chart a third way between Enlightenment rationality and radical skepticism with an approach that he labels regressive philosophy. Regressive philosophy, Perelman argues, provides the human community with a mode of philosophical reasoning located between the extremes of Enlightenment rationality and radical skepticism. In this space between extremes, Perelman identifies contingent truths and values dependent on a rhetorical mode of reasoning, one making moral judgments possible.To best understand "First Philosophies," we recognize the importance of historical context in the development of social theories of knowledge (see Delacampagne 1999; Kennedy 1999). The intellectual networks in which philosophers operate also influence the development of philosophical systems, as Randall Collins has aptly documented. In addition to historical context and intellectual networks, Frederick Beiser has recently noted: "[t] he best introduction to any philosophy is the biography of the person who created it" (1999, 5). He argues that textual analysis alone cannot illuminate the motivation or meaning of a philosophy. A sense of Perelman's biography and the cultural influences that gave rise to "First Philosophies" are necessary for a proper understanding of its themes. For Perelman, the primary intellectual exigencies of the post-war period were the interrelated crises of justice, philosophical reasoning, and responsibility to which "First Philosophies" is a... (shrink)

"The book as a whole seeks to reinvigorate an academic discipline (philosophy of religion) which has fallen on hard times, and to do so by building a bridge between philosophy and empirical-historical studies of religion. The topic is both significant and timely. Too long the empiricists have been inadequately sophisticated philosophically and too long the philosophers have ignored historical data both in its breadth and depth. In not only calling for bridges between these disciplines, but actually building some, the work (...) makes a significant contribution to both." -- Alan Miller "This book is useful because it provides some insights both into the ways scholars think about various aspects of religious behavior, and also information about important features of such behavior. Both myth and philosophy are topics of great significance, and have been discussed by many philosophers and historians of religions and some anthropologists. An interesting set of questions about the nature of religion, and nature of philosophy and their relationships (and also about the nature of myth and its relationship to philosophy) is emerging at the forefront of academic discussions in departments of religion, departments of philosophy, and departments of anthropology. It contains some well-written and conceptually interesting essays." -- E. Thomas Lawson. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy and Rhetoric 36.3 (2003) 177-188 [Access article in PDF] Chaïm Perelman's "First Philosophies and Regressive Philosophy":Commentary and Translation David A. Frank Michelle K. Bolduc Chaïm Perelman's 1949 article, "First Philosophies and Regressive Philosophy," has remained unavailable to readers unable to read French. Our commentary and translation is intended to provide English readers access to the context, influences, and themes that make the article an extraordinarily important (...) work in the history of twentieth-century rhetoric. In this article, Perelman offers a powerful critique of first philosophies and anticipates the problems of radical postmodernity. "First Philosophies" remains a strikingly elegant attempt to foil what Foucault (1984, 41-42) has called the "Enlightenment blackmail of reason," the assumption held by logical positivists and radical skeptics that if reason does not yield absolute and eternal Enlightenment knowledge, there can be no knowledge.Perelman and Lucie Olbrechts-Tyteca's New Rhetoric project avoids Enlightenment blackmail by charting a third way between logical positivism and radical relativism, and "First Philosophies" sets forth the project's philosophical blueprint. Commencing in 1947 and culminating in 1958 with the publication of Traité de l'argumentation: La nouvelle rhétorique, Perelman and Olbrechts-Tyteca sought, discovered, and developed a philosophical system designed as a rapprochement between dialectic (reason and logic) and rhetoric (the art of adapting arguments to audiences). Historians of rhetoric judge the work a "grand revolution" (Meyer 1999, 259), believing it marks a rhetorical renaissance in Europe, and suggest nothing like it will appear for another 100 years after its publication (Johnstone 1971). The New Rhetoric project influenced Gadamer and a host of post-war European and American thinkers (Mootz 1998). Michael Leff calls the 1970 English translation of Traité a "bombshell" (1994, 510). Beyond its historical importance, Crosswhite suggests that the New Rhetoric project is "the single most important event in contemporary rhetorical theory" (1996, 35)and "First Philosophies" marks Perelman's turn from logical [End Page 177] positivism to rhetoric, offering prescient answers to the post-World War II crises of reason, and the ideas in the article provide the Traité'sphilosophical glue (see in particular the English translation, 62).Perelman joined many post-war theorists, including Horkheimer and Adorno (1972), in the resistance to the reign of a disembodied Enlightenment rationality. However, Perelman identified what Habermas (1987, 119) would later call the "performative contradiction" in the conclusion that radical skepticism was the only alternative to Enlightenment rationality. In "First Philosophies," Perelman responds directly to Sartre's 1943 Being and Nothingness (198; see translation below) by exposing the failure of radical skeptics to see that they had been held hostage by Enlightenment blackmail in accepting the Enlightenment criterion for truth, rejecting it, and then making skepticism an absolute. Indeed, "First Philosophies" navigates from this performative contradiction to chart a third way between Enlightenment rationality and radical skepticism with an approach that he labels regressive philosophy. Regressive philosophy, Perelman argues, provides the human community with a mode of philosophical reasoning located between the extremes of Enlightenment rationality and radical skepticism. In this space between extremes, Perelman identifies contingent truths and values dependent on a rhetorical mode of reasoning, one making moral judgments possible.To best understand "First Philosophies," we recognize the importance of historical context in the development of social theories of knowledge (see Delacampagne 1999; Kennedy 1999). The intellectual networks in which philosophers operate also influence the development of philosophical systems, as Randall Collins has aptly documented. In addition to historical context and intellectual networks, Frederick Beiser has recently noted: "[t] he best introduction to any philosophy is the biography of the person who created it" (1999, 5). He argues that textual analysis alone cannot illuminate the motivation or meaning of a philosophy. A sense of Perelman's biography and the cultural influences that gave rise to "First Philosophies" are necessary for a proper understanding of its themes. For Perelman, the primary intellectual exigencies of the post-war period were the interrelated crises of justice, philosophical reasoning, and responsibility to which "First Philosophies" is a... (shrink)

Recent work on conditional reasoning argues that denying the antecedent [DA] and affirming the consequent [AC] are defeasible but cogent patterns of argument, either because they are effective, rational, albeit heuristic applications of Bayesian probability, or because they are licensed by the principle of total evidence. Against this, we show that on any prevailing interpretation of indicative conditionals the premises of DA and AC arguments do not license their conclusions without additional assumptions. The cogency of DA and AC inferences rather (...) depends on contingent factors extrinsic to, and independent of, what is asserted by DA and AC arguments. arguments do not license their conclusions without additional assumptions. The cogency of DA and AC inferences rather depends on contingent factors extrinsic to, and independent of, what is asserted by DA and AC arguments. (shrink)

The particular design of any technology may have profound social implications. Computing technologies are deeply intermeshed with the activities of daily life, playing an ever more central role in how we work, learn, communicate, socialize, and participate in government. Despite the many ways they have improved life, they cannot be regarded as unambiguously beneficial or even value-neutral. Recent experience shows they can lead to unintended but harmful consequences. Some technologies are thought to threaten democracy through the spread of propaganda on (...) online social networks, or to threaten privacy through the aggregation of datasets that include increasingly personal information, or to threaten justice when machine learning is used in such high-stakes, decision-making contexts as loan application reviews, employment procedures, or parole hearings. It is insufficient to ethically assess technology after it has produced negative social impacts, as has happened, for example, with facial recognition software that discriminates against people of color and with self-driving cars that are unable to cope with pedestrians who jay-walk. Developers of new technologies should aim to identify potential harmful consequences early in the design process and take steps to eliminate or mitigate them. This task is not easy. Designers will often have to negotiate among competing values—for instance, between efficiency and accessibility for a diverse user population, or between maximizing benefits and avoiding harm. There is no simple recipe for identifying and solving ethical problems. -/- Computer science education can help meet these challenges by making ethical reasoning about computing technologies a central element in the curriculum. Students can learn to think not only about what technology they could create, but also whether they should create that technology. Learning to reason this way requires courses unlike those currently standard in computer science curricula. A range of university courses on topics in areas of computing, ethics, society and public policy are emerging to meet this need. Some cover computer science broadly, while others focus on specific problems like privacy and security; typically, these classes exist as stand-alone courses in the computer science curriculum. Others have integrated ethics into the teaching of introductory courses on programming, artificial intelligence, and human-computer interaction. (shrink)

Social Ontology encompasses a wide variety of inquiries into the nature, structure and perhaps essence of social phenomena, and their role and place in our world. Topics of research in Social Ontology range from small-scale interactions to large-scale institutions, from spontaneous teamwork to the functioning of formal organizations, and from unintended consequences to institutional design. Social Ontology brings together theoretical work from a large number of disciplines. This rapidly evolving field of research has attracted increasing attention over the last couple (...) of decades, and the conceptual tools recent research in Social Ontology has provided have proved to be useful in a large number of domains, such as the study of the evolution of communication, the structure of social norms, social structure, and social change, the nature of collective responsibility, and the status of corporate agents. The Journal of Social Ontology aims to further this research. It provides a forum of exchange between scholars of diverse disciplinary, scholarly, and methodological backgrounds, and invites submissions from all branches of Social Ontology. The Journal of Social Ontology adopts strict standards of selection and relies heavily on its carefully selected referees. In a world in which publication strategies and outlets are changing at a tremendous pace, it is difficult to say what the future of scholarly publication will look like. With a generous grant from the University of Vienna for the start-up phase, the Journal of Social Ontology now appears as an Open Access Journal with De Gruyter, thus combining professional support by an established publisher with unlimited accessibility. In addition, the Journal of Social Ontology has been founded together with the International Social Ontology Society (ISOS) that supports the work of this journal. We wish to express our thanks to our supporters, contributors, and referees; we hope that our joint effort will grant the work published in this journal the impact it deserves. (shrink)

David Braddon-Mitchell and Frank Jackson’s popular introduction to philosophy of mind and cognition is now available in a fully revised and updated edition. Ensures that the most recent developments in the philosophy of mind and cognitive science are brought together into a coherent, accessible whole. Revisions respond to feedback from students and teachers and make the volume even more useful for courses. New material includes: a section on Descartes’ famous objection to materialism; extended treatment of connectionism; coverage of (...) the view that psychology is autonomous; fuller discussion of recent debates over phenomenal experience; and much more. (shrink)

Environmental health research produces scientific knowledge about environmental hazards crucial for public health and environmental justice movements that seek to prevent or reduce exposure to these hazards. The environment in environmental health research is conceptualized as the range of possible social, biological, chemical, and/or physical hazards or risks to human health, some of which merit study due to factors such as their probability and severity, the feasibility of their remediation, and injustice in their distribution. This paper explores the ethics of (...) identifying the relevant environment for environmental health research, as judgments involved in defining an environmental hazard or risk, judgments of that hazard or risk's probability, severity, and/ or injustice, as well as the feasibility of its remediation, all ought to appeal to non-epistemic as well as epistemic values. I illustrate by discussing the case of environmental lead, a housing-related hazard that remains unjustly distributed by race and class and is particularly dangerous to children. Examining a controversy in environmental health research ethics where researchers tested multiple levels of lead abatement in lead-contaminated households, I argue that the broader perspective on the ethics of environmental health research provided in the first part of this paper may have helped prevent this controversy. (shrink)

This paper discusses ethical issues surrounding Integrated Assessment Models (IAMs) of the economic effects of climate change, and how climate economists acting as policy advisors ought to represent the uncertain possibility of catastrophe. Some climate economists, especially Martin Weitzman, have argued for a precautionary approach where avoiding catastrophe should structure climate economists’ welfare analysis. This paper details ethical arguments that justify this approach, showing how Weitzman’s “fat tail” probabilities of climate catastrophe pose ethical problems for widely used IAMs. The main (...) claim is that economists who ignore or downplay catastrophic risks in their representations of uncertainty likely fall afoul of ethical constraints on scientists acting as policy advisors. Such scientists have duties to honestly articulate uncertainties and manage (some) inductive risks, or the risks of being wrong in different ways. (shrink)

Pancreatitis is a complex, progressively destructive inflammatory disorder. Alcohol was long thought to be the primary causative agent, but genetic contributions have been of interest since the discovery that rare PRSS1, CFTR and SPINK1 variants were associated with pancreatitis risk. We now report two associations at genome-wide significance identified and replicated at PRSS1-PRSS2 and X-linked CLDN2 through a two-stage genome-wide study. The PRSS1 variant likely affects disease susceptibility by altering expression of the primary trypsinogen gene. The CLDN2 risk allele is (...) associated with atypical localization of claudin-2 in pancreatic acinar cells. The homozygous CLDN2 genotype confers the greatest risk, and its alleles interact with alcohol consumption to amplify risk. These results could partially explain the high frequency of alcohol-related pancreatitis in men. © 2012 Nature America, Inc. All rights reserved. (shrink)

Recently, invasion biologists have argued that some of the skepticism expressed in the scientific and lay literatures about the risks of invasive species and other aspects of the consensus within invasion biology is a kind of science denialism. This paper presents an argument that, while some claims made by skeptics of invasion biology share important features with paradigm cases of science denialism, others express legitimate ethical concerns that, even if one disagrees, should not be dismissed as denialist. Further, this case (...) illustrates a more general point about ethical disagreement within sciences like invasion biology that constitutively pursue non-epistemic goals and values. While philosophers of science have argued that epistemic disagreement within science can be productive as heterogeneous epistemic communities “hedge their bets,” the case of invasion biology shows how non-epistemic or ethical disagreement within sciences, while carrying significant risks, can also be epistemically and non-epistemically valuable. (shrink)

Moral puzzles about actions which bring about very small or what are said to be imperceptible harms or benefits for each of a large number of people are well known. Less well known is an argument by Warren Quinn that standard theories of rationality can lead an agent to end up torturing himself or herself in a completely foreseeable way, and that this shows that standard theories of rationality need to be revised. We show where Quinn's argument goes wrong, and (...) apply this to the moral puzzles. (shrink)

Judgements of the value or likelihood of a focal object or outcome have been shown to vary dramatically as a function of whether judgement is based on selective or comparative processing. This article explores the question of when selective versus comparative processing is likely, and demonstrates that as motivation and opportunity to process information carefully (operationalised as accountability and time pressure, respectively) decrease, the likelihood of selective processing increases. Moreover, we document how individuals manage to render judgements when in selective (...) processing mode by relying on categorical knowledge. (shrink)

This article presents results from a multidisciplinary research project on the integration and transfer of language knowledge into robots as an empirical paradigm for the study of language development in both humans and humanoid robots. Within the framework of human linguistic and cognitive development, we focus on how three central types of learning interact and co-develop: individual learning about one's own embodiment and the environment, social learning (learning from others), and learning of linguistic capability. Our primary concern is how these (...) capabilities can scaffold each other's development in a continuous feedback cycle as their interactions yield increasingly sophisticated competencies in the agent's capacity to interact with others and manipulate its world. Experimental results are summarized in relation to milestones in human linguistic and cognitive development and show that the mutual scaffolding of social learning, individual learning, and linguistic capabilities creates the context, conditions, and requisites for learning in each domain. Challenges and insights identified as a result of this research program are discussed with regard to possible and actual contributions to cognitive science and language ontogeny. In conclusion, directions for future work are suggested that continue to develop this approach toward an integrated framework for understanding these mutually scaffolding processes as a basis for language development in humans and robots. (shrink)

Significant associations have been found between specific human leukocyte antigen (HLA) alleles and organ transplant rejection, autoimmune disease development, and the response to infection. Traditional searches for disease associations have conventionally measured risk associated with the presence of individual HLA alleles. However, given the high level of HLA polymorphism, the pattern of amino acid variability, and the fact that most of the HLA variation occurs at functionally important sites, it may be that a combination of variable amino acid sites shared (...) by several alleles (shared epitopes) are better descriptors of the actual causative genetic variants. Here we describe a novel approach to genetic association analysis in which genes/proteins are broken down into smaller sequence features and then variant types defined for each feature, allowing for independent analysis of disease association with each sequence feature variant type. We have used this approach to analyze a cohort of systemic sclerosis patients and show that a sequence feature composed of specific amino acid residues in peptide binding pockets 4 and 7 of HLA-DRB1 explains much of the molecular determinant of risk for systemic sclerosis. (shrink)

According to Richard Jeffrey’s value-free ideal, scientists should avoid making value judgments about inductive risks by offering explicit representations of scientific uncertainty to decision-makers, who can use these to make decisions according to their own values. Some philosophers have responded by arguing that higher-order inductive risks arise in the process of producing representations of uncertainty. This chapter explores this line of argument and its limits, arguing that the Jeffreyan value-free ideal is achievable in contexts where methodological decisions introduce minimal higher-order (...) uncertainty and where communications of uncertainty are unlikely to be manipulated or misunderstood by scientists or decision-makers. This chapter illustrates the limits of the Jeffreyan ideal with reference to climate science and argues that the context of climate science is not conducive to the Jeffreyan ideal, so the argument that climate modeling is value-laden due to higher-order inductive risks withstands recent criticisms. (shrink)

This critical note responds to Guiaşu and Tindale’s “Logical fallacies and invasion biology,” from our perspective as ecologists and philosophers of science engaged in debates about invasion biology and invasive species. We agree that “the level of charges and dismissals” surrounding these debates might be “unhealthy” and that “it will be very difficult for dialogues to move forward unless genuine attempts are made to understand the positions being held and to clarify the terms involved.” Although they raise several important scientific, (...) conceptual, and ethical issues at the foundations of invasion biology, we believe Guiaşu and Tindale’s attempts to clarify the debate were unsuccessful. Like some other critics of the field, they tend to misrepresent invasion biology by cherry-picking and constructing “straw people,” inaccurately portraying invasion biology, and thus failing to elevate the dialogue. In this critique, we clarify areas in the invasion biology literature misrepresented by Guiaşu and Tindale. We attempt to provide a more balanced view of areas of reasonable debate within invasion biology, including disputes about empirical evidence, diverse risk attitudes, and other diverse ethical commitments. (shrink)

An $\omega$-categorical supersimple group is finite-by-abelian-by-finite, and has finite SU-rank. Every definable subgroup is commensurable with an acl-definable subgroup. Every finitely based regular type in a CM-trivial $\omega$-categorical simple theory is non-orthogonal to a type of SU-rank 1. In particular, a supersimple $\omega$-categorical CM-trivial theory has finite SU-rank.

Background Various authorities recommend the participation of patients in promoting patient safety, but little is known about health care professionals' (HCPs') attitudes towards patients' involvement in safety-related behaviours. Objective To investigate how HCPs evaluate patients' behaviours and HCP responses to patient involvement in the behaviour, relative to different aspects of the patient, the involved HCP and the potential error. Design Cross-sectional fractional factorial survey with seven factors embedded in two error scenarios (missed hand hygiene, medication error). Each survey included two (...) randomized vignettes that described the potential error, a patient's reaction to that error and the HCP response to the patient. Setting Twelve hospitals in Switzerland. Participants A total of 1141 HCPs (response rate 45%). Measurements Approval of patients' behaviour, HCP response to the patient, anticipated effects on the patient–HCP relationship, HCPs' support for being asked the question, affective response to the vignettes. Outcomes were measured on 7-point scales. Results Approval of patients' safety-related interventions was generally high and largely affected by patients' behaviour and correct identification of error. Anticipated effects on the patient–HCP relationship were much less positive, little correlated with approval of patients' behaviour and were mainly determined by the HCP response to intervening patients. HCPs expressed more favourable attitudes towards patients intervening about a medication error than about hand sanitation. Conclusions This study provides the first insights into predictors of HCPs' attitudes towards patient engagement in safety. Future research is however required to assess the generalizability of the findings into practice before training can be designed to address critical issues. (shrink)

The two envelope paradox can be dissolved by looking closely at the connection between conditional and unconditional expectation and by being careful when summing an infinite series of positive and negative terms. The two envelope paradox is not another St. Petersburg paradox and that one does not need to ban talk of infinite expectation values in order to dissolve it. The article ends by posing a new puzzle to do with infinite expectations.

We solve a major open problem concerning algorithmic properties of products of ‘transitive’ modal logics by showing that products and commutators of such standard logics asK4,S4,S4.1,K4.3,GL, orGrzare undecidable and do not have the finite model property. More generally, we prove that no Kripke complete extension of the commutator [K4, K4] with product frames of arbitrary finite or infinite depth (with respect to both accessibility relations) can be decidable. In particular, ifl1andl2are classes of transitive frames such that their depth cannot be (...) bounded by any fixedn< ω, then the logic of the class {5ℑ1× ℑ2∣ ℑ1∈l1, ℑ2, ∈l2} is undecidable. (On the contrary, the product of, say,K4and the logic of all transitive Kripke frames of depth ≤n, for some fixedn< ω, is decidable.) The complexity of these undecidable logics ranges from r.e. to co-r.e. and Π11-complete. As a consequence, we give the first known examples of Kripke incomplete commutators of Kripke complete logics. (shrink)

Stakeholder theory is widely recognized as a management theory, yet very little research has considered its implications for individual managerial decision-making. In the two studies reported here, we used stakeholder theory to examine managerial decisions about balancing stakeholder interests. Results of Study 1 suggest that indivisible resources and unequal levels of stakeholder saliency constrain managers’ efforts to balance stakeholder interests. Resource divisibility also influenced whether managers used a within-decision or an across-decision approach to balance stakeholder interests. In Study 2 we (...) examined instrumental and normative implications of these two approaches. We conclude by considering the contributions of this research. (shrink)

Computational models of memory presented in this issue reflect varied empirical data and levels of representation. From mathematical models to neural and cognitive architectures, all aim to converge on a unified theory of the mind.

In the absence of access to formal credit, informal contracts with independent investors give the small ranchers of the Lower Amazon an acceptable means through which to surmount the high investment hurdle of starting a cattle herd. These contracts – called sociedades – allow small ranchers to raise an outside investor's cattle in return for a portion of the offspring and are commonplace in the cattle production systems of the Amazon. But, notwithstanding a vast literature on cattle production in the (...) Amazon, informal contracts have been largely overlooked. This paper presents the results of a field survey and financial analysis for informal contracts on small ranches in the Lower Amazon. In the results, we suggest that informal contracts are an important means of cattle herd start-up and herd production for small ranchers. Internal rates of returns in cattle production under these contracts are in the range of –7 to –12% for the small rancher and 12% for the investor. The net present value of the contract to the small rancher ranges from –R$1219 to –R$8599 and from R$1681 to R$8845 for the investor, for a 10-year period, depending on herd size. Financial returns contracts are sensitive to the contract design – e.g., to who pays health costs – and to beef prices. The small ranchers have a negative IRR, lose money, and bear all the risk of loss, yet persist in using this form of herd development. We surmise that this is due to the non-financial benefits of cattle ownership and the lack of access to formal credit structures. In conclusion, although outside the formal economy and apparently financially unrewarding, these contracts are an important mechanism by which the small ranchers on the Amazon Floodplains create cattle herds. (shrink)