We introduce a predicative version of topos based on the notion of small maps in algebraic set theory, developed by Joyal and one of the authors. Examples of stratified pseudotoposes can be constructed in Martin-Löf type theory, which is a predicative theory. A stratified pseudotopos admits construction of the internal category of sheaves, which is again a stratified pseudotopos. We also show how to build models of Aczel-Myhill constructive set theory using this categorical structure.

In this paper we present and study a categorical formulation of the W-types of Martin-Löf. These are essentially free term algebras where the operations may have finite or infinite arity. It is shown that W-types are preserved under the construction of sheaves and Artin gluing. In the proofs we avoid using impredicative or nonconstructive principles.

This paper provides an explicit description of a model for intuitionistic non-standard arithmetic, which can be formalized in a constructive metatheory without the axiom of choice.

In this paper, we give a constructive nonstandard model of intuitionistic arithmetic (Heyting arithmetic). We present two axiomatisations of the model: one finitary and one infinitary variant. Using the model these axiomatisations are proven to be conservative over ordinary intuitionistic arithmetic. The definition of the model along with the proofs of its properties may be carried out within a constructive and predicative metatheory (such as Martin-Löf's type theory). This paper gives an illustration of the use of sheaf semantics to obtain (...) effective proof-theoretic results.The axiomatisations of nonstandard intuitionistic arithmetic (to be calledHAIandHAIωrespectively) as well as their model are based on the construction in [5] of a sheaf model for arithmetic using a site of filters. In this paper we present a “minimal” version of this model, built instead on a suitable site of provable filter bases. The construction of this site can be viewed as an extension of the well-known construction of the classifying topos for a geometric theory which uses “syntactic sites”. (Such sites can in fact be used to prove semantical completeness of first order logic in a strictly constructive framework, see [6].)We should mention that for classical nonstandard arithmetics there are several nonconstructive methods of proving conservativity over arithmetic, e.g. the compactness theorem, Mac Dowell–Specker's theorem [3]. (shrink)

In this paper, we give a constructive nonstandard model of intuitionistic arithmetic (Heyting arithmetic). We present two axiomatisations of the model: one finitary and one infinitary variant. Using the model these axiomatisations are proven to be conservative over ordinary intuitionistic arithmetic. The definition of the model along with the proofs of its properties may be carried out within a constructive and predicative metatheory (such as Martin-Löf's type theory). This paper gives an illustration of the use of sheaf semantics to obtain (...) effective proof-theoretic results.The axiomatisations of nonstandard intuitionistic arithmetic (to be calledHAIandHAIωrespectively) as well as their model are based on the construction in [5] of a sheaf model for arithmetic using a site of filters. In this paper we present a “minimal” version of this model, built instead on a suitable site of provable filter bases. The construction of this site can be viewed as an extension of the well-known construction of the classifying topos for a geometric theory which uses “syntactic sites”. (Such sites can in fact be used to prove semantical completeness of first order logic in a strictly constructive framework, see [6].)We should mention that for classical nonstandard arithmetics there are several nonconstructive methods of proving conservativity over arithmetic, e.g. the compactness theorem, Mac Dowell–Specker's theorem [3]. (shrink)

This paper aims to give an informal introduction to the ways in which a topos can be viewed as an intuitionistic universe of sets. In particular, it is explained how infinitesimal real numbers and various types of ordinal numbers arise in this context.

This paper provides a partial solution to the completeness problem for Joyal's axiomatization of open and etale maps, under the additional assumption that a collection axiom holds.

This article aims to read feminist new materialisms (Barad), together with ‘postulated’ linguistic or cultural primacy of Queer Theory (Butler), to show how both are engaged in similar critical-ethical endeavours. The central argument is that the criticism of Barad and new materialisms misses Butler’s materialistic insights due to a narrow interpretation of Butler's alleged social-constructivist position. There is, therefore, a specific focus on where they both make similar ethical appeals. Moreover, the article relies on Adorno's negative dialectic to highlight an (...) interpretation of Barad and Butler as being part of the same dialectical movement, in which materialism and idealism fluctuate in their mutual criticisms, thus continuing the procession towards 'new knowledge' and emancipation, or freedom, through their motions back and forth. (shrink)

This is the first in a series of papers on Predicative Algebraic Set Theory, where we lay the necessary groundwork for the subsequent parts, one on realizability [B. van den Berg, I. Moerdijk, Aspects of predicative algebraic set theory II: Realizability, Theoret. Comput. Sci. . Available from: arXiv:0801.2305, 2008], and the other on sheaves [B. van den Berg, I. Moerdijk, Aspects of predicative algebraic set theory III: Sheaf models, 2008 ]. We introduce the notion of a predicative category (...) with small maps and show that it provides a sound and complete semantics for constructive set theories like IZF and CZF. The main technical contribution of this paper is that it shows in detail that such categories can always be conservatively embedded in categories that are exact. These exactness properties play a crucial rôle in showing that predicative categories with small maps contain models of set theory and that they are closed under sheaves and realizability. We will prove the former statement in this paper as well, leaving a proof of the closure properties to the papers on realizability and sheaves as mentioned above. (shrink)

The development of transplantation technology increasingly places before society a multitude of diverse, complex ethical and legal problems. The subject is the more complex because of the various divergent interests involved. There are the interests of the donor of organs, who has a right to protection of his legal position, and those of the patient in need of an often lifesaving organ. There are also the interests of the donor’s relatives, after his death, and those of the transplantation surgeons. The (...) international dimension of transplantation technology makes the picture even more complicated. Though this article is devoted to the European situation, the problems are similar all over the world. (shrink)

The development of transplantation technology increasingly places before society a multitude of diverse, complex ethical and legal problems. The subject is the more complex because of the various divergent interests involved. There are the interests of the donor of organs, who has a right to protection of his legal position, and those of the patient in need of an often lifesaving organ. There are also the interests of the donor’s relatives, after his death, and those of the transplantation surgeons. The (...) international dimension of transplantation technology makes the picture even more complicated. Though this article is devoted to the European situation, the problems are similar all over the world. (shrink)

We propose an extension of Aczel's constructive set theory CZF by an axiom for inductive types and a choice principle, and show that this extension has the following properties: it is interpretable in Martin-Löf's type theory. In addition, it is strong enough to prove the Set Compactness theorem and the results in formal topology which make use of this theorem. Moreover, it is stable under the standard constructions from algebraic set theory, namely exact completion, realizability models, forcing as well as (...) more general sheaf extensions. As a result, methods from our earlier work can be applied to show that this extension satisfies various derived rules, such as a derived compactness rule for Cantor space and a derived continuity rule for Baire space. Finally, we show that this extension is robust in the sense that it is also reflected by the model constructions from algebraic set theory just mentioned. (shrink)

This study described the relationships between academic class and student moral sensitivity and reasoning and between curriculum design components for ethics education and student moral sensitivity and reasoning. The data were collected from freshman (n = 506) and senior students (n = 440) in eight baccalaureate nursing programs in South Korea by survey; the survey consisted of the Korean Moral Sensitivity Questionnaire and the Korean Defining Issues Test. The results showed that moral sensitivity scores in patient-oriented care and conflict were (...) higher in senior students than in freshman students. Furthermore, more hours of ethics content were associated with higher principled thinking scores of senior students. Nursing education in South Korea may have an impact on developing student moral sensitivity. Planned ethics content in nursing curricula is necessary to improve moral sensitivity and moral reasoning of students. (shrink)

Is the procreation asymmetry intuitively supported? According to a recent article in this journal, an experimental study suggests the opposite. Dean Spears (2020) claims that nearly three-quarters of participants report that there is a reason to create a person just because that person’s life would be happy. In reply, I argue that various confounding factors render the study internally invalid. More generally, I show how one might come to adopt the procreation asymmetry for the wrong reasons by misinterpreting one’s intuitions.

Philosophers ask just whose expression, if anyone’s, we hear in lyric poetry. Walton provides a novel possibility: it’s the reader who “uses” the poem (just as a speech giver uses a speech) who makes the language expressive. But worries arise once we consider poems in particular social or political settings, those which require a strong self-other distinction, or those with expressions that should not be disassociated from the subjects whose experience they draw from. One way to meet this challenge is (...) to consider the poem expressive of a plural subject, which frees us from looking for a particular individual whose voice we hear in the work, whether she be fictional or actual. Some lyrics give voice to a group whose experience is attended to in the work. This may be done through a posited fictional speaker, but the ontology of the speaker is shown to be less important. Attending to a group whose concerns are voiced allows us to explain how poems can manage to address our-worldly concerns even when lacking actual persons whose expressions we encounter in the poems. (shrink)

The Shape of Thought: How Mental Adaptations Evolve presents a road map for an evolutionary psychology of the twenty-first century. It brings together theory from biology and cognitive science to show how the brain can be composed of specialized adaptations, and yet also an organ of plasticity. Although mental adaptations have typically been seen as monolithic, hard-wired components frozen in the evolutionary past, The Shape of Thought presents a new view of mental adaptations as diverse and variable, with distinct functions (...) and evolutionary histories that shape how they develop, what information they use, and what they do with that information. The book describes how advances in evolutionary developmental biology can be applied to the brain by focusing on the design of the developmental systems that build it. Crucially, developmental systems can be plastic, designed by the process of natural selection to build adaptive phenotypes using the rich information available in our social and physical environments. This approach bridges the long-standing divide between "nativist" approaches to development, based on innateness, and "empiricist" approaches, based on learning. It shows how a view of humans as a flexible, culturally-dependent species is compatible with a complexly specialized brain, and how the nature of our flexibility can be better understood by confronting the evolved design of the organ on which that flexibility depends. (shrink)

This paper offers a unified explanation for the procreation asymmetry and the non-identity thesis – two of the most intractable puzzles in population ethics. According to the procreation asymmetry, there are moral reasons not to create lives that are not worth living but no moral reasons to create lives that are worth living. I explain the procreation asymmetry by arguing that there are moral reasons to prevent the bad, but no moral reasons to promote the good. Various explanations for the (...) procreation asymmetry have failed to explain the non-identity thesis: if one could create a person with a good life or a different person with a better life, one has a moral reason to create the better life. I argue that reflections on the misfortune of unfulfilled potential allow us to circumvent the non-identity problem. (shrink)

I argue, first, that the deprived individuals whose predicaments Nussbaum cites as examples of "adaptive preference" do not in fact prefer the conditions of their lives to what we should regard as more desirable alternatives, indeed that we believe they are badly off precisely because they are not living the lives they would prefer to live if they had other options and were aware of them. Secondly, I argue that even where individuals in deprived circumstances acquire tastes for conditions that (...) we regard as bad, they are typically better off having their acquired preferences satisfied. If they are badly off it is because they cannot get what we and they, would regard as more desirable alternatives. Preference utilitarianism explains why individuals in such circumstances are badly off whether they have adapted to their deprived circumstances or not. Even if they prefer the conditions of their lives to all other available alternatives, most would prefer alternatives that are not available to them which would, on the preferentist account, make them better off. And that, on the preferentist account, is the basis for a radical critique of unjust institutions that limit people's options and prevent them from getting what they want. (shrink)

Intent and mitigating circumstances play a central role in moral and legal assessments in large-scale industrialized societies. Al- though these features of moral assessment are widely assumed to be universal, to date, they have only been studied in a narrow range of societies. We show that there is substantial cross-cultural variation among eight traditional small-scale societies (ranging from hunter-gatherer to pastoralist to horticulturalist) and two Western societies (one urban, one rural) in the extent to which intent and mitigating circumstances influence (...) moral judgments. Although participants in all societies took such factors into account to some degree, they did so to very different extents, varying in both the types of considerations taken into account and the types of violations to which such considerations were applied. The particular patterns of assessment characteristic of large-scale industrialized societies may thus reflect relatively recently culturally evolved norms rather than inherent features of human moral judgment. (shrink)

Currently, there is widespread skepticism that higher cognitive processes, given their apparent flexibility and globality, could be carried out by specialized computational devices, or modules. This skepticism is largely due to Fodor's influential definition of modularity. From the rather flexible catalogue of possible modular features that Fodor originally proposed has emerged a widely held notion of modules as rigid, informationally encapsulated devices that accept highly local inputs and whose operations are insensitive to context. It is a mistake, however, to equate (...) such features with computational devices in general and therefore to assume, as Fodor does, that higher cognitive processes must be non‐computational. Of the many possible non‐Fodorean architectures, one is explored here that offers possible solutions to computational problems faced by conventional modular systems: an ‘enzymatic’ architecture. Enzymes are computational devices that use lock‐and‐key template matching to identify relevant information (substrates), which is then operated upon and returned to a common pool for possible processing by other devices. Highly specialized enzymes can operate together in a common pool of information that is not pre‐sorted by information type. Moreover, enzymes can use molecular ‘tags’ to regulate the operations of other devices and to change how particular substrates are construed and operated upon, allowing for highly interactive, context‐specific processing. This model shows how specialized, modular processing can occur in an open system, and suggests that skepticism about modularity may largely be due to failure to consider alternatives to the standard model. (shrink)

Is there a pro tanto moral reason to create a life merely because it would be good for the person living it? Proponents of the procreation asymmetry claim there is not. Defending this controversial no reason claim, some have suggested that it is well in line with other phenomena in the moral realm: there is no reason to give a promise merely because one would keep it, and there is no reason to procreate merely to increase the extent of justice (...) in the world. Allegedly, some analogs extend so far as to support a unified theory of the no reason claim and the nonidentity thesis, that is, the view that of two persons leading lives of positive wellbeing, there is a reason to create the person with higher wellbeing. I dismantle the proposed analogs and show that they fail to meet various desiderata. Moreover, I refute Johann Frick's argument that the no reason claim follows from the assumption that reasons of beneficence are reasons to act for the sake of people. By criticizing attractive defenses for the no reason claim, I weaken its plausibility. (shrink)

We applaud the spirit of MacNeilage's attempts to better explain the evolution and cortical control of speech by drawing on the vast literature in nonhuman primate neurobiology. However, he oversimplifies motor cortical fields and their known individual functions to such an extent that he undermines the value of his effort. In particular, MacNeilage has lumped together the functional characteristics across multiple mesial and lateral motor cortex fields, inadvertantly creating two hypothetical centers that simply may not exist.

Amyloid beta precursor protein (APP) and prion protein (PrP) are cell membrane elements implicated in neurodegenerative diseases. Both proteins undergo endoproteolysis. Evidence is adduced from the literature hinting that the process in the two proteins could be related, their functions may overlap and their distributions coincide. It is proposed that PrP catalyses its own cleavage, the C-terminal fragment functions as an α secretase and the N-terminal segment chaperones the active site; the α secretase releases anticoagulant and neurotrophic ectodomains from APP. (...) The proposals explain some features of spongiform encephalopathies. BioEssays 23:456–462, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

Der private, sehr gefahrdete Bucherbestand Friedrich Nietzsches gilt als ein besonders interessantes Beispiel einer Schriftstellerbibliothek des 19. Jahrhunderts.

Maintenance and promotion of patient dignity is an ethical responsibility of healthcare workers. The aim of this study was to investigate patient dignity and related factors in patients with heart failure. In this qualitative study, 22 patients with heart failure were chosen by purposive sampling and semi-structured interviews were conducted until data saturation. Factors related to patient dignity were divided into two main categories: patient/care index and resources. Intrapersonal features (inherent characteristics and individual beliefs) and interpersonal interactions (communication, respect, enough (...) information, privacy, and authority) were classified as components of the patient/care index category. Human resources (management and staff) and environmental resources (facilities and physical space) were classified as components of the resources category. The results will increase healthcare staff's understanding of patient dignity and its related factors, and provide information regarding the development of systems and processes that support patients in ways that are consistent with these values. (shrink)