According to the local risk-neutrality theorem an agent who has the opportunity to invest in an uncertain asset does not buy it or sell it short iff its expected value is equal to its price, independently of the agent's attitude towards risk. Contrary to that it is shown that, in the context of expected utility theory with differentiable vNM utility function, but without the assumption of stochastic constant returns to scale, nondegenerate intervals of no-trade prices may exist. With a quasiconcave (...) expected utility function they do if, and only if, the agent is risk averse of order one. (shrink)

Harald Weinrich's epilogue considers forgetting in the present age of information overflow, particularly in the area of the natural sciences."--Jacket.

Together, these collected papers develop the idea that human thinking - from scientific creativity to simply understanding what a positive HIV test means - "happens" partly outside the mind.".

The essays in this collection have been written for Gerd Buchdahl, by colleagues, students and friends, and are self-standing pieces of original research which have as their main concern the metaphysics and philosophy of science of the seventeenth and eighteenth centuries. They focus on issues about the development of philosophical and scientific thought which are raised by or in the work of such as Bernoulli, Descartes, Galileo, Kant, Leibniz, Maclaurin, Priestly, Schelling, Vico. Apart from the initial bio-bibliographical piece and (...) those by Robert Butts and Michael Power, they do not discuss Buchdahl or his ideas in any systematic, lengthy, or detailed way. But they are collected under a title which alludes to the book, Metaphysics and the Philosophy of Science: The Classical Origins, Descartes to Kant (1969), which is central in the corpus of his work, and deal with the period and some of the topics with which that book deals. (shrink)

What Chow calls NHSTP is an inconsistent hybrid of Fisherian and Neyman-Pearsonian ideas. In psychology it has been practiced like ritualistic handwashing and sustained by wishful thinking about its utility. Chow argues that NHSTP is an important tool for ruling out chance as an explanation for data. I disagree. This ritual discourages theory development by providing researchers with no incentive to specify hypotheses.

Simple Heuristics That Make Us Smart invites readers to embark on a new journey into a land of rationality that differs from the familiar territory of cognitive science and economics. Traditional views of rationality tend to see decision makers as possessing superhuman powers of reason, limitless knowledge, and all of eternity in which to ponder choices. To understand decisions in the real world, we need a different, more psychologically plausible notion of rationality, and this book provides it. It is about (...) fast and frugal heuristics--simple rules for making decisions when time is pressing and deep thought an unaffordable luxury. These heuristics can enable both living organisms and artificial systems to make smart choices, classifications, and predictions by employing bounded rationality. But when and how can such fast and frugal heuristics work? Can judgments based simply on one good reason be as accurate as those based on many reasons? Could less knowledge even lead to systematically better predictions than more knowledge? Simple Heuristics explores these questions, developing computational models of heuristics and testing them through experiments and analyses. It shows how fast and frugal heuristics can produce adaptive decisions in situations as varied as choosing a mate, dividing resources among offspring, predicting high school drop out rates, and playing the stock market. As an interdisciplinary work that is both useful and engaging, this book will appeal to a wide audience. It is ideal for researchers in cognitive psychology, evolutionary psychology, and cognitive science, as well as in economics and artificial intelligence. It will also inspire anyone interested in simply making good decisions. (shrink)

Life is short. This indisputable fact of existence has driven human ingenuity since antiquity, whether through efforts to lengthen our lives with medicine or shorten the amount of time we spend on work using technology. Alongside this struggle to manage the pressure of life’s ultimate deadline, human perception of the passage and effects of time has also changed. In On Borrowed Time, Harald Weinrich examines an extraordinary range of materials—from Hippocrates to Run Lola Run—to put forth a new conception (...) of time and its limits that, unlike older models, is firmly grounded in human experience. Weinrich’s analysis of the roots of the word time connects it to the temples of the skull, demonstrating that humans first experienced time in the beating of their pulses. Tracing this corporeal perception of time across literary, religious, and philosophical works, Weinrich concludes that time functions as a kind of sixth sense—the crucial sense that enables the other five. Written with Weinrich’s customary narrative elegance, On Borrowed Time is an absorbing—and, fittingly, succinct—meditation on life’s inexorable brevity. (shrink)

The well-known proposal to consider the Lüders-von Neumann measurement as a non-classical extension of probability conditionalization is further developed. The major results include some new concepts like the different grades of compatibility, the objective conditional probabilities which are independent of the underlying state and stem from a certain purely algebraic relation between the events, and an axiomatic approach to quantum mechanics. The main axioms are certain postulates concerning the conditional probabilities and own intrinsic probabilistic interpretations from the very beginning. A (...) Jordan product is derived for the observables, and the consideration of composite systems leads to operator algebras on the Hilbert space over the complex numbers, which is the standard model of quantum mechanics. The paper gives an expository overview of the results presented in a series of recent papers by the author. For the first time, the complete approach is presented as a whole in a single paper. Moreover, since the mathematical proofs are already available in the original papers, the present paper can dispense with the mathematical details and maximum generality, thus addressing a wider audience of physicists, philosophers or quantum computer scientists. (shrink)

Humans and animals make inferences about the world under limited time and knowledge. In contrast, many models of rational inference treat the mind as a Laplacean Demon, equipped with unlimited time, knowledge, and computational might. Following H. Simon's notion of satisficing, the authors have proposed a family of algorithms based on a simple psychological mechanism: one-reason decision making. These fast and frugal algorithms violate fundamental tenets of classical rationality: They neither look up nor integrate all information. By computer simulation, the (...) authors held a competition between the satisficing "Take The Best" algorithm and various "rational" inference procedures. The Take The Best algorithm matched or outperformed all competitors in inferential speed and accuracy. This result is an existence proof that cognitive mechanisms capable of successful performance in the real world do not need to satisfy the classical norms of rational inference. (shrink)

A demarcation between kant's general metaphysics (transcendental principles) and his special metaphysics is attempted, through a discussion of kant's three accounts of lawlikeness, 'transcendental', 'empirical' and 'metaphysical'. the distinctions are defended via a number of 'indicators' in kant's writings, and the 'looseness of fit' between the different types of lawlikeness is discussed.

Unlike behaviorism, cognitive psychology relies on mental concepts to explain behavior. Yet mental processes are not directly observable and multiple explanations are possible, which poses a challenge for finding a useful framework. In this article, I distinguish three new frameworks for explanations that emerged after the cognitive revolution. The first is called tools‐to‐theories: Psychologists' new tools for data analysis, such as computers and statistics, are turned into theories of mind. The second proposes as‐if theories: Expected utility theory and Bayesian statistics (...) are turned into theories of mind, describing an optimal solution of a problem but not its psychological process. The third studies the adaptive toolbox (formal models of heuristics) that describes mental processes in situations of uncertainty where an optimal solution is unknown. Depending on which framework researchers choose, they will model behavior in either situations of risk or of uncertainty, and construct models of cognitive processes or not. The frameworks also determine what questions are asked and what kind of data are generated. What all three frameworks have in common, however, is a clear preference for formal models rather than explanations by general dichotomies or mere verbal concepts. The frameworks have considerable potential to inform each other and to generate points of integration. (shrink)

This volume collects Gigerenzer's recent articles on the psychology of rationality. This volume should appeal, like the earlier volumes, to a broad mixture of cognitive psychologists, philosophers, economists, and others who study decision making.

Axiomatic rationality is defined in terms of conformity to abstract axioms. Savage limited axiomatic rationality to small worlds, that is, situations in which the exhaustive and mutually exclusive set of future states S and their consequences C are known. Others have interpreted axiomatic rationality as a categorical norm for how human beings should reason, arguing in addition that violations would lead to real costs such as money pumps. Yet a review of the literature shows little evidence that violations are actually (...) associated with any measurable costs. Limiting axiomatic rationality to small worlds, I propose a naturalized version of rationality for situations of intractability and uncertainty, all of which are not in. In these situations, humans can achieve their goals by relying on heuristics that may violate axiomatic rationality. The study of ecological rationality requires formal models of heuristics and an analysis of the structures of environments these can exploit. It lays the foundation of a moderate naturalism in epistemology, providing statements about heuristics we should use in a given situation. Unlike axiomatic rationality, ecological rationality can explain less-is-more effects, formalize when one should move from ‘is’ to ‘ought,’ and be evaluated by goals beyond coherence, such as predictive accuracy, frugality, and efficiency. Ecological rationality can be seen as a formalization of means–end instrumentalist rationality, based on Herbert Simon’s insight that rational behavior is a function of the mind and its environment. (shrink)

The degree of success in creating quality care for people suffering from dementia is limited despite extensive research. This article describes healthcare providers’ experience with the ethical challenges and possibilities in the relationship with patients suffering from dementia and its impact on quality care. The material is based on qualitative, in-depth individual narrative interviews with 12 professional healthcare providers from two different nursing homes. The transcribed interview texts were subjected to a phenomenological–hermeneutical interpretation. To provide quality care to patients with (...) dementia, the healthcare providers emphasized the importance of sensing and understanding the patients’ emotional and bodily expressions through sentient attentiveness and recognition of the patient as a person. They also described reciprocity of expressions in the relationship where the patient recognized them both as persons and healthcare providers. The analyses of the findings are, inter alia, discussed in light of Løgstrup’s relational philosophy of ethics. (shrink)

Heuristics are efficient cognitive processes that ignore information. In contrast to the widely held view that less processing reduces accuracy, the study of heuristics shows that less information, computation, and time can in fact improve accuracy. We review the major progress made so far: the discovery of less-is-more effects; the study of the ecological rationality of heuristics, which examines in which environments a given strategy succeeds or fails, and why; an advancement from vague labels to computational models of heuristics; the (...) development of a systematic theory of heuristics that identifies their building blocks and the evolved capacities they exploit, and views the cognitive system as relying on an “adaptive toolbox;” and the development of an empirical methodology that accounts for individual differences, conducts competitive tests, and has provided evidence for people’s adaptive use of heuristics. Homo heuristicus has a biased mind and ignores part of the available information, yet a biased mind can handle uncertainty more efficiently and robustly than an unbiased mind relying on more resource-intensive and general-purpose processing strategies. (shrink)

In the study of the arithmetic degrees the $\omega \text {-REA}$ sets play a role analogous to the role the r.e. degrees play in the study of the Turing degrees. However, much less is known about the arithmetic degrees and the role of the $\omega \text {-REA}$ sets in that structure than about the Turing degrees. Indeed, even basic questions such as the existence of an $\omega \text {-REA}$ set of minimal arithmetic degree are open. This paper makes progress on (...) this question by demonstrating that some promising approaches inspired by the analogy with the r.e. sets fail to show that no $\omega \text {-REA}$ set is arithmetically minimal. Finally, it constructs a $\prod ^0_{2}$ singleton of minimal arithmetic degree. Not only is this a result of considerable interest in its own right, constructions of $\prod ^0_{2}$ singletons often pave the way for constructions of $\omega \text {-REA}$ sets with similar properties. Along the way, a number of interesting results relating arithmetic reducibility and rates of growth are established. (shrink)

Evidence-based recommendations for lifestyles to promote healthy cognitive aging root in reductionistic studies of mostly physical measurable factors with large effect sizes. In contrast, most people consider factors like autonomy, purpose, social participation and engagement, etc. as central to a high quality of life in old age. Evidence for a direct causal impact of these factors on healthy cognitive aging is still limited, albeit not absent. Ultimately, however, individual lifestyle is a complex composite of variables relating to both body and (...) mind as well as to receiving input and generating output. The physical interventions are tied to the more subjective and mind-related aspects of lifestyle and wellbeing in the idea of the “embodied mind,” which states that the mind is shaped by and requires the body. The causality is reciprocal and the process is dynamic, critically requiring movement: the “embodied mind” is a “embodied mind in motion.” Hiking, playing musical instruments, dancing and yoga are examples of body–mind activities that assign depth, purpose, meaning, social embedding, etc. to long-term beneficial physical “activities” and increase quality of life not only as delayed gratification. The present motivational power of embodied activities allows benefiting from the side-effects of late-life resilience. The concept offers an access point for unraveling the mechanistic complexity of lifestyle-based prevention, including their neurobiological foundations. (shrink)

What counts as human rationality: reasoning processes that embody content-independent formal theories, such as propositional logic, or reasoning processes that are well designed for solving important adaptive problems? Most theories of human reasoning have been based on content-independent formal rationality, whereas adaptive reasoning, ecological or evolutionary, has been little explored. We elaborate and test an evolutionary approach, Cosmides' social contract theory, using the Wason selection task. In the first part, we disentangle the theoretical concept of a “social contract” from that (...) of a “cheater-detection algorithm”. We demonstrate that the fact that a rule is perceived as a social contract — or a conditional permission or obligation, as Cheng and Holyoak proposed — is not sufficient to elicit Cosmides' striking results, which we replicated. The crucial issue is not semantic, but pragmatic: whether a person is cued into the perspective of a party who can be cheated. In the second part, we distinguish between social contracts with bilateral and unilateral cheating options. Perspective change in contracts with bilateral cheating options turns P & not-Q responses into not-P & Q responses. The results strongly support social contract theory, contradict availability theory, and cannot be accounted for by pragmatic reasoning schema theory, which lacks the pragmatic concepts of perspectives and cheating detection. (shrink)

Gerd Buchdahl; XIV—The Relation Between ‘Understanding’ and ‘Reason’ in the Architectonic of Kant's Philosophy1, Proceedings of the Aristotelian Society, Volume.

Name der Zeitschrift: Frühmittelalterliche Studien Jahrgang: 49 Heft: 1 Seiten: 299-300.

Name der Zeitschrift: Millennium Jahrgang: 12 Heft: 1 Seiten: 179-202.

The paper shows why and how an empirical study of fast-and-frugal heuristics can provide norms of good reasoning, and thus how (and how far) rationality can be naturalized. We explain the heuristics that humans often rely on in solving problems, for example, choosing investment strategies or apartments, placing bets in sports, or making library searches. We then show that heuristics can lead to judgments that are as accurate as or even more accurate than strategies that use more information and computation, (...) including optimization methods. A standard way to defend the use of heuristics is by reference to accuracy-effort trade-offs. We take a different route, emphasizing ecological rationality (the relationship between cognitive heuristics and environment), and argue that in uncertain environments, more information and computation are not always better (the “less-can-be-more” doctrine). The resulting naturalism about rationality is thus normative because it not only describes what heuristics people use, but also in which specific environments one should rely on a heuristic in order to make better inferences. While we desist from claiming that the scope of ecological rationality is unlimited, we think it is of wide practical use. (shrink)

The degree of success in creating quality care for people suffering from dementia is limited despite extensive research. This article describes Healthcare providers’ experience with the ethical challenges and possibilities in the relationship with patients suffering from dementia and its impact on quality care. The material is based on qualitative, in-depth individual narrative interviews with 12 professional Healthcare providers from two different nursing homes. The transcribed interview texts were subjected to a phenomenological–hermeneutical interpretation. To provide quality care to patients with (...) dementia, the Healthcare providers emphasized the importance of sensing and understanding the patients’ emotional and bodily expressions through sentient attentiveness and recognition of the patient as a person. They also described reciprocity of expressions in the relationship where the patient recognized them both as persons and Healthcare providers. The analyses of the findings are, inter alia, discussed in light of Løgstrup’s relational philosophy of ethics. (shrink)