"A Survey of Ranking Theory": The paper gives an up-to-date survey of ranking theory. It carefully explains the basics. It elaborates on the ranking theoretic explication of reasons and their balance. It explains the dynamics of belief statable in ranking terms and indicates how the ranks can thereby be measured. It suggests how the theory of Bayesian nets can be carried over to ranking theory. It indicates what it might mean to objectify ranks. It discusses the formal and the philosophical (...) aspects of the tight relation and the complementarity of ranks and probabilities. It closes with comparative remarks on predecessors and other philosophical proposals as well as formal models developed in AI. (shrink)

Concentrating upon applications that are most relevant to modern physics, this valuable book surveys variational principles and examines their relationship to dynamics and quantum theory. Stressing the history and theory of these mathematical concepts rather than the mechanics, the authors provide many insights into the development of quantum mechanics and present much hard-to-find material in a remarkably lucid, compact form. After summarizing the historical background from Pythagoras to Francis Bacon, Professors Yourgrau and Mandelstram cover Fermat's principle of least time, the (...) principle of least action of Maupertuis, development of this principle by Euler and Lagrange, and the equations of Lagrange and Hamilton. Equipped by this thorough preparation to treat variational principles in general, they proceed to derive Hamilton's principle, the Hamilton-Jacobi equation, and Hamilton's canonical equations. An investigation of electrodynamics in Hamiltonian form covers next, followed by a resume of variational principles in classical dynamics. The authors then launch into an analysis of their most significant topics: the relation between variational principles and wave mechanics, and the principles of Feynman and Schwinger in quantum mechanics. Two concluding chapters extend the discussion to hydrodynamics and natural philosophy. Professional physicists, mathematicians, and advanced students with a strong mathematical background will find this stimulating volume invaluable reading. Extremely popular in its hardcover edition, this volume will find even wider appreciation in its first fine inexpensive paperbound edition. (shrink)

Ranking theory delivers an account of iterated contraction; each ranking function induces a specific iterated contraction behavior. The paper shows how to reconstruct a ranking function from its iterated contraction behavior uniquely up to multiplicative constant and thus how to measure ranks on a ratio scale. Thereby, it also shows how to completely axiomatize that behavior. The complete set of laws of iterated contraction it specifies amend the laws hitherto discussed in the literature.

In addition to discussing some philosophical accounts of common sense, this article considers several ways in which common sense can be altered or disturbed in psychopathology. Common sense can be defined as practical understanding, capacity to see and take things in their right light, sound judgment, or ordinary mental capacity. The philosopher Vico described it as the ability to distinguish the probable from the improbable. Goethe understood common sense as an "organ" that is formed in communication for the purpose of (...) communication. Common sense is rooted in the intersubjective constitution of the life-world. Obsessive-compulsive patients show relatively mild disturbances of common sense. Patients with major affective psychoses, in their premorbid personality structure, are overly attached to common sense. In schizophrenia, however, there seems to be a true abdication of common sense involving a loss of "natural self-evidence." Even in premorbid states, such persons often lose both the sense of tact and the ability to "take things in their right light." Although logic, and the ability to engage in theoretical discussion, may be preserved, there is a loss of interpretive skills and the "faculty of judgment"; this results in an inability to cope with everyday practical and social activity. There is also a characteristic sense of perplexity, a sense of amazement before that which would normally seem self-evident and a frequent tendency to reflect upon the conditions of possibility of existence that otherwise remain concealed. The author suggests that the fragility of common sense should not be seen as a mere deficiency state. Rather, it derives from a basic vulnerability inherent in the very structure of being human. (Abstract written by special issue editor: L.A.S.). (shrink)

Recently, Bengt Hansson presented a paper about dyadic deontic logic,2 criticizing some purely axiomatic systems of dyadic deontic logic and proposing three purely semantical systems of dyadic deontic logic which he confidently called dyadic standard systems of deontic logic (DSDL1–3). Here I shall discuss the third by far most interesting system DSDL3 which is operating with preference relations. First, I shall describe this semantical system (Sections 1.1–1.3). Then I shall give an axiomatic system (Section 1.4) which is proved to be (...) correct (Section 2) and complete (Section 3) with respect to Hansson's semantics. Finally, in face of these results Hansson's semantics will be discussed from a more intuitive standpoint. After emphasizing its intuitive attractiveness (Section 4.1) I will show that two objections often discussed in connection with preference relations do not apply to it (Section 4.2 and 4.3); more precisely, I will show that the connectedness condition for preference relations can be dropped and that, in a sense, it is not necessary to compare two possible worlds differing in infinitely many respects. (What exactly is meant by this, will become clear later on.) Yet there is a third objection to Hansson's semantics which points to a real intuitive inadequacy of DSDL3. A way of removing this inadequacy, which corresponds to Hansson's own intuitions as well as to familiar metaethical views, is suggested, but not technically realized (Section 4.4). In the last section (section 4.5) I shall briefly show that DSDL3 is decidable, as expected. (shrink)

& The functional equivalence of overt movements and dynamic imagery is of fundamental importance in neuroscience. Here, we investigated the participation of the neocortical motor areas in a classic task of dynamic imagery, Shepard and Metzler's mental rotation task, by time-resolved single-trial functional Magnetic Resonance Imaging (fMRI). The subjects performed the mental-rotation task 16 times, each time with different object pairs. Functional images were acquired for each pair separately, and the onset times and..

The paper argues that Gareth Evans’ argument for transparent self-knowledge is based on a conflation of doxastic transparency with ascriptive transparency. Doxastic transparency means that belief about one’s own doxastic state, e.g., the belief that one thinks that it will rain, can be warranted by ordinary empirical observation, e.g., of the weather. In contrast, ascriptive transparency says that self-ascriptions of belief, e.g., “I believe it will rain”, can be warranted by such observation. We first show that the thesis of doxastic (...) transparency is ill-motivated and then offer a non-epistemic interpretation of ascriptive transparency by reference to the theory of explicit expressive acts: “I think it will rain” requires attendance to the weather because the utterance expresses a belief about the weather, not about ourselves. This will allow us to avoid what is often called “the puzzle of transparent self-knowledge” while remaining faithful to Evans’ linguistic observations. (shrink)

Analogical reasoning addresses the question how evidence from various phenomena can be combined and made relevant for theory development and prediction. In the first part of my contribution, I review some influential accounts of analogical reasoning, both historical and contemporary, focusing in particular on Keynes, Carnap, Hesse, and more recently Bartha. In the second part, I sketch a general framework. To this purpose, a distinction between a predictive and a conceptual type of analogical reasoning is introduced. I then take up (...) a common intuition according to which analogical inferences hold if the differences between source and target concern only irrelevant circumstances. I attempt to make this idea more precise by addressing possible objections and in particular by specifying a notion of causal irrelevance based on difference making in homogeneous contexts. (shrink)

This paper attempts to develop a projectivistic understanding of chance or objective probability or partial determination. It does so by critically examining David Lewis’ philosophy of probability and his defense of Humean Supervenience, building thereupon the constructive projectivistic alternative, which will basically be a suitable reinterpretation of de Finetti’s position. Any treatment of the topic must show how it extends to natural necessity or deterministic laws or full determination in perfect parallel. The paper indicates at the end how this demand (...) can be met. (shrink)

We define classes Φnof formulae of first-order arithmetic with the following properties:(i) Everyφϵ Φnis classically equivalent to a Πn-formula (n≠ 1, Φ1:= Σ1).(ii)(iii)IΠnandiΦn(i.e., Heyting arithmetic with induction schema restricted to Φn-formulae) prove the same Π2-formulae.We further generalize a result by Visser and Wehmeier. namely that prenex induction within intuitionistic arithmetic is rather weak: After closing Φnboth under existential and universal quantification (we call these classes Θn) the corresponding theoriesiΘnstill prove the same Π2-formulae. In a second part we consideriΔ0plus collection-principles. We (...) show that both the provably recursive functions and the provably total functions ofare polynomially bounded. Furthermore we show that the contrapositive of the collection-schema gives rise to instances of the law of excluded middle and hence. (shrink)

This paper deals with Hans Reichenbach's common cause principle. It was propounded by him in, and has been developed and widely applied by Wesley Salmon, e.g. in and. Thus, it has become one of the focal points of the continuing discussion of causation. The paper addresses five questions. Section 1 asks: What does the principle say? And section 2 asks: What is its philosophical significance? The most important question, of course, is this: Is the principle true? To answer that question, (...) however, one must first consider how one might one argue about it at all. One can do so by way of examples, the subject of section 3, or more theoretically, which is the goal of section 4. Based on an explication of probabilistic causation proposed by me in,, and, section 4 shows that a variant of the principle is provable within a classical framework. The question naturally arises whether the proved variant is adequate, or too weak. This is pursued in section 5. My main conclusion will be that some version of Reichenbach's principle is provably true, and others may be. This may seem overly ambitious, but it is not. The paper does not make any progress on essential worries about the common cause principle arising in the quantum domain; it only establishes more rigorously what has been thought to be plausible at least within a classical framework. (shrink)

The paper proposes two principles of coherence (thus taking up work started in Spohn (1991) "A Reason for Explanation: Explanations Provide Stable Reasons"). The latter indeed serves as a weak, but precise explication of the notion of coherence as it is used in the current epistemological discussion. After discussing their epistemological setting, the paper considers four ways of establishing these principles. They may be inferred neither from enumerative induction, nor from the nature of propositions as objects of belief, nor in (...) a Kantian way from self-consciousness. Rather, I propose a fairly rigorous way to infer them from an even more fundamental rationality principle of non-dogmatism and an elementary theory of perception. (shrink)

We examine the performance of some standard causal discovery algorithms, both constraint-based and score-based, from the perspective of how robust they are against failures of the Causal Faithfulness Assumption. For this purpose, we make only the so-called Triangle-Faithfulness assumption, which is a fairly weak consequence of the Faithfulness assumption, and otherwise allows unfaithful distributions. In particular, we allow violations of Adjacency-Faithfulness and Orientation-Faithfulness. We show that the PC algorithm, a representative constraint-based method, can be made more robust against unfaithfulness by (...) incorporating elements of the GES algorithm, a representative score-based method; similarly, the GES algorithm can be made less error-prone by incorporating elements of the conservative PC algorithm. As our simulations demonstrate, the increased robustness seems to matter even when faithfulness is not exactly violated, for with only finite sample, distributions that are not exactly unfaithful may be sufficiently close to being unfaithful to make trouble. (shrink)

Modern theory of rationality has truly grown into a science of its own. Still, the general topic remained a genuinely philosophical one. This essay is concerned with giving a brief overview. Section 2 explains the fundamental scheme of all rationality assessments. With its help, a schematic order of the main questions concerning the theory of rationality can be given; the questions turn out to be quite unevenly addressed in the literature. Section 3 discusses the fundamental issue that the theory of (...) rationality seems to be both a normative and an empirical theory. Section 4, finally, shows how the unity of the theory of rationality can nevertheless be maintained. (shrink)

The paper is based on ranking theory, a theory of degrees of disbelief (and hence belief). On this basis, it explains enumerative induction, the confirmation of a law by its positive instances, which may indeed take various schemes. It gives a ranking theoretic explication of a possible law or a nomological hypothesis. It proves, then, that such schemes of enumerative induction uniquely correspond to mixtures of such nomological hypotheses. Thus, it shows that de Finetti's probabilistic representation theorems may be transformed (...) into an account of confirmation of possible laws and that enumerative induction is equivalent to such an account. The paper concludes with some remarks about the apriority of lawfulness or the uniformity of nature. (shrink)

This paper investigates whether managerial rhetoric in the Management Discussion and Analysis section of 10-K filings can help gauge the level of managerial opportunism in a firm. We find that the use of trust-related words is connected to inefficient investment decisions and poor operating performance. Furthermore, firms making more frequent use of trust-related words are subject to less monitoring by institutional investors or analysts. Their accounting also relies more heavily on discretionary accruals. These results are consistent with the notion that (...) managerial rhetoric to advertise trustworthiness points towards agency problems plaguing the firm. (shrink)

An infinite binary sequence X is Kolmogorov–Loveland random if there is no computable non-monotonic betting strategy that succeeds on X in the sense of having an unbounded gain in the limit while betting successively on bits of X. A sequence X is KL-stochastic if there is no computable non-monotonic selection rule that selects from X an infinite, biased sequence.One of the major open problems in the field of effective randomness is whether Martin-Löf randomness is the same as KL-randomness. Our first (...) main result states that KL-random sequences are close to Martin-Löf random sequences in so far as every KL-random sequence has arbitrarily dense subsequences that are Martin-Löf random. A key lemma in the proof of this result is that for every effective split of a KL-random sequence at least one of the halves is Martin-Löf random. However, this splitting property does not characterize KL-randomness; we construct a sequence that is not even computably random such that every effective split yields two subsequences that are 2-random. Furthermore, we show for any KL-random sequence A that is computable in the halting problem that, first, for any effective split of A both halves are Martin-Löf random and, second, for any computable, nondecreasing, and unbounded function g and almost all n, the prefix of A of length n has prefix-free Kolmogorov complexity at least n−g. Again, the latter property does not characterize KL-randomness, even when restricted to left-r.e. sequences; we construct a left-r.e. sequence that has this property but is not KL-stochastic and, in fact, is not even Mises–Wald–Church stochastic.Turning our attention to KL-stochasticity, we construct a non-empty class of KL-stochastic sequences that are not weakly 1-random; by the usual basis theorems we obtain such sequences that in addition are left-r.e., are low, or are of hyperimmune-free degree.Our second main result asserts that every KL-stochastic sequence has effective dimension 1, or equivalently, a sequence cannot be KL-stochastic if it has infinitely many prefixes that can be compressed by a factor of α<1. This improves on a result by Muchnik, who has shown that were they to exist, such compressible prefixes could not be found effectively. (shrink)

An abridged and translated edition of two of Wolfgang Ernst’s major works, representing the ambitious claim of a comprehensive knowledge-oriented analysis of media temporalities.

The central claim of the paper is, roughly, that the fact that it looks to somebody as if p is a defeasibly a priori reason for assuming that p (and vice versa), for any person, even for the perceiver himself. As a preparation, it outlines a doxastic conception suitable to explicate this claim and explains how to analyse dispositions within this conception. Since an observable p has the disposition to look as if p, this analysis generalizes to the central claim (...) which is then argued to be at the bottom of coherentism. Thus, the defense of the claim supports coherentism as opposed to foundationalism and at the same time provides an answer to skepticism about the external world. (shrink)

The Dialectica-style functional interpretation of Kripke-Platek set theory with infinity ( $\hbox{\sf KP} \omega$ ) given in [1] uses a choice functional (which is not a definable set function of ( $hbox{\sf KP} \omega$ ). By means of a Diller-Nahm-style interpretation (cf. [4]) it is possible to eliminate the choice functional and give an interpretation by set functionals primitive recursive in $x\mapsto\omega$ . This yields the following characterization: The class of $\Sigma$ -definable set functions of $\hbox{\sf KP} \omega$ coincides with (...) the collection of set functionals of type 1 primitive recursive in $x\mapsto \omega$. (shrink)

In the present paper we give a functional interpretation of Aczel's constructive set theories CZF − and CZF in systems T ∈ and T ∈ + of constructive set functionals of finite types. This interpretation is obtained by a translation × , a refinement of the ∧ -translation introduced by Diller and Nahm 49–66) which again is an extension of Gödel's Dialectica translation. The interpretation theorem gives characterizations of the definable set functions of CZF − and CZF in terms of (...) constructive set functionals. In a second part we introduce constructive set theories in all finite types. We expand the interpretation to these theories and give a characterization of the translation × . We further show that the simplest non-trivial axiom of extensionality is not interpretable by functionals of T ∈ and T ∈ + . We obtain this result by adapting Howard's notion of hereditarily majorizable functionals to set functionals. Subject of the last section is the translation ∨ that is defined in Burr for an interpretation of Kripke-Platek set theory with infinity. (shrink)

The paper argues that the standard decision theoretic account of strategies and their rationality or optimality is much too narrow, that strategies should rather condition future action to future decision situations (a point of view already developed in my Grundlagen der Entscheidungstheorie, sect. 4.4), that practical deliberation must therefore essentially rely on a relation of superiority and inferiority between possible future decision situations, that all this allows to substantially broaden the theory of practical rationality, that a long list of points (...) attended to in the literature can be subsumed under the broadened perspective (including a novel view on the iterated prisoner's dilemma and on iterated Newcomb's problem, which, however, is revised in Spohn (2003) "Dependency Equilibria and the Causal Structure of Decision and Game Situation"), and that the task to complete and systematize this list indeed forms a fruitful research programme. (shrink)

The subject of this paper is a characterization of the $\Sigma_1$ -definable set functions of Kripke-Platek set theory with infinity and a uniform version of axiom of choice: $KP\omega+(uniform\;AC)$ . This class of functions is shown to coincide with the collection of set functionals of type 1 primitive recursive in a given choice functional and $x\mapsto\omega$ . This goal is achieved by a Gödel Dialectica-style functional interpretation of $KP\omega+(uniform\;AC)$ and a computability proof for the involved functionals.

The Dialectica-style functional interpretation of Kripke-Platek set theory with infinity (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $\hbox{\sf KP} \omega$\end{document}) given in [1] uses a choice functional (which is not a definable set function of (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $hbox{\sf KP} \omega$\end{document}). By means of a Diller-Nahm-style interpretation (cf. [4]) it is possible to eliminate the choice functional and give an interpretation by set functionals primitive recursive in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} (...) \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $x\mapsto\omega$\end{document}. This yields the following characterization: The class of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $\Sigma$\end{document}-definable set functions of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $\hbox{\sf KP} \omega$\end{document} coincides with the collection of set functionals of type 1 primitive recursive in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $x\mapsto \omega$\end{document}. (shrink)

The paper is essentially a short version Spohn "Strategic Rationality" which emphasizes in particular how the ideas developed there may be used to shed new light on the iterated prisoner's dilemma (and on iterated Newcomb's problem).

This paper is on dangerous human experimentations with drugs against trypanosimiasis carried out in the former German colonies of German East Africa and Togo. Victory over trypanosomiasis could not be achieved in Berlin because animals were thought to be unsuitable for therapeutic laboratory research in the field of trypanosomiasis. The colonies themselves were necessarily chosen as laboratories and the patients with sleeping sickness became the objects of therapeutical and pharmacological research. The paper first outlines Robert Koch's trypanosomiasis research in the (...) large sleeping sickness laboratory of German East Africa and then focuses on the escalating human experiments on trypanosomiasis in the German Musterkolonie Togo, which must be interpreted as a reaction to the starting signal given by Robert Koch in East Africa. (shrink)

The paper pleads for compatibilism by distinguishing the first-person’s normative and the observer’s empirical perspective. In the normative perspective one’s own actions are uncaused and free, in the empirical perspective they are caused and may be predetermined. Still, there is only one notion of causation that is able to account for the relation between the causal conceptions within the two perspectives. The other main idea for explicating free will by explaining free actions or intentions as appropriately caused in a specified (...) way is acknowledged, but not discussed. The paper finally argues that the normative and the empirical perspective are on a par; none is prior; even from within the empirical perspective the normative perspective is ineliminable. (shrink)

Our studies of aesthetics and knowledge have long tended to privilege the visual - at the expense, Wolfgang Ernst argues, of the aural. 'Sonic Time Machines' aims to correct that, presenting a striking new approach to theorising sound that investigates its split existence: as a temporal effect in a techno-cultural context and as a source of knowledge and information. Ernst creates a new term for the concept at the heart of the book, "sonicity," a flexible and powerful term that (...) allows him to consider sound with all its many physical, philosophical, and cultural valences."--Page 4 de la couverture. (shrink)

The paper analyzes the meaning of color terms within the framework of Kaplan's character theory (which, when generalized to a treatment of hidden indexicality or dependence on the context world, can perfectly accommodate Kripke's notions of apriority and of (metaphysical) necessity). It explains this framework and why it might be fruitfully applied to color terms. Then it defends six theses: that (1) the predicate "is red" and (2) even the relation "appears red to" are hidden indexicals (i.e., have, as used (...) in English, different extensions in different context worlds), that (3) the phenomenal, the comparative, and the epistemic reading of "appears red to" are not three different readings, but reflect the context world dependence of this term, that (4) the statement "x is red iff x would appear red to most English-speaking people under normal conditions" is a priori in English, but analytic only in one reading and not in another, and that these observations account well for the epistemology of color terms and allow us to be metaphysically conservative by claiming that our context world is presumably such that (5) the statement "x appears red to y iff x (appropriately) causes y to be in a certain (disjunctive) neural state N" is necessarily true and (6) the statement "x is red iff the reflectance spectrum of the surface of x is of some (disjunctive) kind R" is necessarily true as well. (shrink)

Projecting essence onto a social category means to think, talk, and act as if the category were a discrete natural kind and as if its members were all endowed with the same immutable attributes determined by the category's essence. Essentializing may happen implicitly or on purpose in representing ingroups and outgroups. We argue that essentializing is a versatile representational tool that is used to create identity in groups with chosen membership in order to make the group appear as a unitary (...) entity, that outsiders often draw on a group's essentialist self-construal in their judgements about the groups, that judgements about members of forced social categories are often informed by essentialist thinking that easily switches to discrimination and racism, and that under certain historical and political conditions members of social categories and groups may contest their essentialized identity, such as parts of the feminist movement, or that they may attempt to reconstruct an essentialized identity, such as parts of the homosexual movement or the largely defunct European nobility. Besides explicit political and power interests, we see communication processes and language use as a tacit force driving essentialization of social categories. (shrink)

"Mit den digitalen Medien haben sich neue Formen der Warenzirkulation auf der Grundlage sozialer Netzwerke etabliert, die unter dem Begriff Sharing Economy zusammen- gefasst werden. Die Durchsetzung dieser onlinebasierten Transaktionen ist von einem euphorischen Diskurs begleitet, der der Sharing Economy utopische Potenziale einer gemeinschaftlichen Mehrwerterzeugung zuschreibt. Wolfgang Sützls Beitrag betont, dass die rhetorische Wirkung des Teilens und dessen Idealisierung über den Tausch als eigentliche ökomische Form hinwegtäusche. Anhand von Gabentheorien zeigt er auf, wie das Teilen (durch die Leugnung der (...) Äquivalenzerwartungen) an seine Grenzen komme, indem es mit dem Geben verwechselt werde, und außerdem Wertschöpfungsprozesse von Unternehmen sowie die Verwertung von Ressourcen verschleiere. Den Gedanken, dass diese zur ›Ökonomisierbarkeit von allem‹ neige, greift auch Tomasz Konicz auf, der in der Ökonomie des Teilens einen ›anomalen‹ Wunsch nach alternativen Wirtschaftsformen angesichts der ›Krise des Kapitals‹ erkennt. Dafür bringt Konicz aus einer marxistischen Perspektive den ›prozessierenden Widerspruch‹ der Technologieentwicklung und ihre verheerenden Implikationen in Anschlag, die auch die Grundlage der Sharing Economy darstellen. Insofern sei die Suche nach Alternativen noch offen. With the digital media, new forms of the circulation of goods have been established on the basis of social networks, summarily addressed under the term ‘sharing economy.’ The enforcement of these online transactions is accompanied by a euphoric discourse, ascribing to the sharing economy utopian potentials to commonly generate added value. Wolfgang Sützl’s contribution emphasizes that the rhetorical effect of sharing and its idealization distract from exchange as basic economic form. With reference to theories of gift exchange, he shows how sharing (by denying the expectation of equivalence) reaches its limits by being confused with giving, and how it also conceals the value-creation processes of companies as well as the exploitation of resources. Tomasz Konicz also picks up on the idea that the sharing economy tends to an ‘economization of everything,’ seeing in it an ‘anomalous’ desire for alternative forms of economy in the face of the ‘crisis of capital.’ On the other hand, from a Marxist perspective, Konicz points to the ‘processing contradiction’ of technology development and its devastating implications, which also form the basis of the sharing economy. In this respect, the search for alternatives still goes on. ". (shrink)

The aim of this article is to give an introduction to functional interpretations of set theory given by the authorin Burr (2000a). The first part starts with some general remarks on Gödel's functional interpretation with a focus on aspects related to problems that arise in the context of set theory. The second part gives an insight in the techniques needed to perform a functional interpretation of systems of set theory. However, the first part of this article is not intended to (...) be a complete survey of functional interpretations and here we recommend, for example, Avigad and Feferman (1998),Troelstra (1990) and Troelstra (1973). (shrink)