From Leibniz to Krauss philosophers and scientists have raised the question as to why there is something rather than nothing. Why-questions request a type of explanation and this is often thought to include a deductive component. With classical logic in the background only trivial answers are forthcoming. With free logics in the background, be they of the negative, positive or neutral variety, only question-begging answers are to be expected. The same conclusion is reached for the modal version of the (...) Question, namely ‘Why is there something contingent rather than nothing contingent?’. The categorial version of the Question, namely ‘Why is there something concrete rather than nothing concrete?’, is also discussed. The conclusion is reached that deductive explanations are question-begging, whether one works with classical logic or positive or negative free logic. I also look skeptically at the prospects of giving causal-counterfactual or probabilistic answers to the Question, although the discussion of the options is less comprehensive and the conclusions are more tentative. The meta-question, viz. ‘Should we not stop asking the Question’, is accordingly tentatively answered affirmatively. (shrink)

This article argues against scientistic arguments of the redundancy of religious belief structures due to the explicability of the physical world, as exemplified here by a discussion of the “popular science” of Richard Dawkins and Lawrence Krauss. It is claimed that the root of belief in “sense” is in animation, rather than in cosmological creation myths. The paper displays that the ideal of the absolute is linguistically signified by the termini “survival” and “freedom” in human understanding. However, it does (...) not appear through human understanding as an illusion stemming from the illegitimate inference of a pantheistic spirit or prime mover. Instead, human reason builds an analytical understanding upon a fundamental instinct, which long predates human-level consciousness. Approaching the subject’s role in the physical world, the article displays that animation itself, as the primal form of awareness and agency, is the urge to overcome an inherent antagonism in the structure of being. It is argued that the cosmological argument is mirrored by an argument that has no strict theoretical cogency, but is likewise irreducible and irrefutable by science. Science investigates the object empirically but has limited explanatory capabilities when it comes to subjective being. (shrink)

The focus of this article is the question whether the notion of being in a position to know is closed under modus ponens. The question is answered negatively.

Many philosophical discussions hinge on the concept of knowability. For example, there is a blooming literature on the so-called paradox of knowability. How to understand this notion, however? In this paper, we examine several approaches to the notion: the naive approach to take knowability as the possibility to know, the counterfactual approach endorsed by Edgington (1985) and Schlöder (2019) , approaches based on the notion of a capacity or ability to know (Fara 2010, Humphreys 2011), and finally, approaches that make (...) use of the resources of dynamic epistemic logic (van Benthem 2004, Holliday 2017). (shrink)

This paper provides an analysis of the intrinsic/extrinsic distinction, as applied both to properties and to relations. In contrast to other accounts, the approach taken here locates the source of a property’s intrinsicality or extrinsicality in the manner in which that property is ‘logically constituted’, and thus – plausibly – in its nature or essence, rather than in e.g. its modal profile. Another respect in which the present proposal differs from many extant analyses lies in the fact that it does (...) not seek to analyse the ‘global’ distinction between intrinsic and extrinsic properties on the basis of the ‘local’ distinction between having a property intrinsically and having it extrinsically. Instead, the latter distinction is explicated on the basis of the former. (shrink)

In a recent paper Horsten embarked on a journey along the limits of the domain of the unknowable. Rather than knowability simpliciter, he considered a priori knowability, and by the latter he meant absolute provability, i.e. provability that is not relativized to a formal system. He presented an argument for the conclusion that it is not absolutely provable that there is a natural number of which it is true but absolutely unprovable that it has a certain property. The argument depends (...) on a description principle. I will argue that the latter principle implies the knowability of all arithmetical truths. Therefore, Horsten's argument is either sound but its conclusion is trivial, or his argument is unsound. (shrink)

This paper considers whether Marx's views about communism change significantly during his lifetime. According to the ‘standard story’, as Marx got older he dropped the vision of self-realization in labour that he spoke of in his early writings, and adopted a more pessimistic account of labour, where real freedom is achieved outside the working-day, in leisure. Other commentators, however, have argued that there is no pessimistic shift in Marx's thought on this matter. This paper offers a different reading of this (...) debate. It argues that there are two visions of the good life in Marx. However, it suggests that these two visions cannot be understood in terms of a simple shift between a ‘young’ and ‘mature’ Marx. Rather, it claims that Marx moves between these two visions throughout his writings. In this way, it suggests that Marx's intellectual development on this issue is best understood as an oscillation rather than a shift. Once this interpretive claim is advanced, the paper then moves on to consider some potential causes and implications of Marx's life-long oscillation between two different conceptions of the good life. (shrink)

Many scholars have argued that the distinction between the natural and the unnatural does not have any moral relevance, either because the distinction does not make sense or because, even if it does make sense, it does not make any moral sense. Before we can decide on the latter, we must therefore determine first whether a semantic distinction can be made. In this article, I argue that the distinction can be maintained. In spite of the fact that the categories of (...) the natural and the unnatural are blurred as no unnatural things are completely unnatural, I argue that we can meaningfully distinguish between different types of unnaturalness along the natural-unnatural spectrum. To my knowledge, this article is the first publication to distinguish between three types of unnaturalness. (shrink)

In recent years the idea that perceptual content is tensed in the sense that we can perceive objects as present or as past has come under attack. In this paper the notion of tensed content is to the contrary defended. The paper argues that assuming that something like an intentionalistic theory of perception is correct, it is very reasonable to suppose that perceptual content is tensed, and that a denial of this notion requires a denial of some intuitively very plausible (...) principles. The paper discusses some common objections against the notion of tensed content and concludes that none of them succeeds in showing that perceptual content cannot be tensed. (shrink)

Almost all philosophers agree that a necessary condition on lying is that one says what one believes to be false. But, philosophers haven’t considered the possibility that the true requirement on lying concerns, rather, one’s degree-of-belief. Liars impose a risk on their audience. The greater the liar’s confidence that what she asserts is false, the greater the risk she’ll think she’s imposing on the dupe, and, therefore, the greater her blameworthiness. From this, I arrive at a dilemma: either the belief (...) requirement is wrong, or lying isn’t interesting. I suggest an alternative necessary condition for lying on a degree-of-belief framework. (shrink)

The material conditional and the suppositional analysis of the indicative conditional are based on different philosophical foundations and they leave important successes of their competitor unexplained. This paper unifies both accounts within a truth-functional, trivalent model of the suppositional analysis. In this model, we observe that the material and the suppositional conditional exhibit the same logical behavior while they have different truth conditions and different probabilities. The result is a unified semantic analysis that closes an important gap in the suppositional (...) story and explains the persistent appeal of the material conditional analysis for philosophers and psychologists of reasoning. (shrink)

In his 1953 lectures at the College de France, Merleau-Ponty dedicated much effort to further developing his idea of embodied subject and interpreted fresh sources that he did not use in Phenomenology of Perception. Notably, he studied more in depth the neurological notion of "body schema". According to Merleau-Ponty, the body schema is a practical diagram of our relationships to the world, an action-based norm with reference to which things make sense. Merleau-Ponty more precisely tried to describe the fundamentally dynamic (...) unity of the body, i.e. the fact there are various possibilities how the practical "diagram" of body schema could be de-differentiated (in pathology) or further refined (via cognitive and cultural superstructures, symbolic systems). This chapter summarises Merleau-Ponty's interpretation of the notion, while contrasting it to the more traditional understanding of the body in phenomenology and recent philosophical texts dealing with body schema. (shrink)

Background and aim Healthcare professionals are regularly exposed to moral challenges in patient care potentially compromising quality of care and safety of patients. Preventive clinical ethics support aims to identify and address moral problems in patient care at an early stage of their development. This study investigates the occurrence, risk factors, early indicators, decision parameters, consequences and preventive measures of moral problems. Method Semi-structured expert interviews were conducted with 20 interprofessional healthcare professionals from 2 university hospitals in Basel, Switzerland. A (...) Likert scale questionnaire was completed by the interviewees and analysed using descriptive and inferential statistics. Results Healthcare professionals are frequently exposed to a variety of moral problems, such as end-of-life decisions, resource allocation and assessing the patient's will or decisional capacity. Thirty-four different risk factors for moral problems are identified, e.g. patient vulnerability, divergent values or world views, inadequate resources or poor ethical climate. Twenty-one early indicators are recognised such as disagreement between healthcare professionals, patients and relatives, emotional disturbances, gut feeling or conflict of conscience. A variety of preventive measures are suggested and presented in a preventive clinical ethics support process model. The most helpful measures are early ethical conversations with colleagues, early team-internal ethical case discussions and an ethics-trained contact person on the ward. Ethics training, kerbside consultations, proactive ethics consultations, ethics screening and rounds are also considered helpful. Conclusions Clinical ethics support services should not only offer reactive and complex, but also proactive and low-threshold support for healthcare professionals, patients and relatives. (shrink)

This book provides for the first time a complete history of the doctrine of the transcendentals and shows its importance for the understanding of philosophy in the Middle Ages.

On the standard interpretation, if a person holds cyclical preferences, the person is prone to acting irrationally. I provide a different interpretation, tying cyclical preferences not to irrationality, but to indecision. According to this alternative understanding – coined the indecision interpretation – top cycles in a person’s preferences can be associated with a difficulty in justifying one’s choice. If an agent’s justificatory impasse persists despite attempts to resolve the cycle, the agent can be deemed undecided. The indecision interpretation is compatible (...) with the standard interpretation of such cycles as instances of irrationality. Yet indecision corresponds to a first-person, non-instrumental perspective on the problem, whereas irrationality usually corresponds to a third-person, instrumental perspective. Due to these differences, interpreting cycles in terms of indecision offers a novel conceptual perspective, pertinent both for explanatory purposes and for the aim of normative theorizing. (shrink)

Carnap's theory of descriptions was restricted in two ways. First, the descriptive conditions had to be non-modal. Second, only primitive predicates or the identity predicate could be used to predicate something of the descriptum . The motivating reasons for these two restrictions that can be found in the literature will be critically discussed. Both restrictions can be relaxed, but Carnap's theory can still be blamed for not dealing adequately with improper descriptions.

Kearns (2021) reconstructs Berkeley’s (1713) Master Argument as a formally valid argument against the Materialist Thesis, with the key premise the Distinct Conceivability Thesis, namely the thesis that truths about sensible objects having or lacking thinkable qualities are (distinctly) conceivable and as its conclusion that all sensible objects are conceived. It will be shown that Distinct Conceivability Thesis entails the Reduction Thesis, which states that de dicto propositional (ordinary or distinct) conceivability reduces to de re propositional (ordinary or distinct) conceivability. (...) While Kearns (2021) set out to avoid the confusion of a de re claim with a de dicto claim, which Prior (1955) accused Berkeley of, Kearns can be accused of making a similar conceptual confusion. (shrink)

In this paper, I provide some evidence for the view that a common charge against those who adopt vegetarianism is that they would be sentimental. I argue that this charge is pressed frequently by those who adopt moral absolutism, a position that I reject, before exploring the question if vegetarianism might make sense. I discuss three concerns that might motivate those who adopt vegetarian diets, including a concern with the human health and environmental costs of some alternative diets, a concern (...) about inflicting pain on animals, and a concern with the killing of animals. While I argue that vegetarianism does not make sense in some situations, I hope that this paper shows that there are many good reasons why the adoption of vegetarian, and—even more so—vegan diets might be appropriate in some situations. In carving out this position, I focus primarily on the question whether a morally relevant distinction between the killing of plants and the killing of animals should be made. I engage primarily with the views of two of the most prominent authors on this issue, arguing that neither Peter Singer nor Tom Regan provide a satisfactory account on the ethics of killing nonhuman organisms. Two views are challenged in particular, the view that relatively simple animals such as molluscs, as well as plants, lack awareness, and the view that animals without a preference to continue living stand to lose little or nothing by being killed. I provide some evidence to support the claim that many share my view that it is more problematic to kill animals than to kill plants, before analyzing why some suppress the negative feelings they associate with killing animals. By exploring these issues I hope to shed some light on the issue of whether the feelings of those who adopt vegetarianism are sentimental or make sense, and to stimulate reflection amongst those with an interest in food ethics. (shrink)

Niels Bohr and Philosophy of Physics: Twenty-First Century Perspectives examines the work, influences and legacy of the Nobel Prize physicist and philosopher of experiment Niels Bohr. While covering Bohr's groundbreaking contribution to quantum mechanics, this collection reveals the philosophers who influenced his work. Linking him to the pragmatist C.I. Lewis and the Danish philosopher Harald Høffding, it draws strong similarities between Bohr's philosophy and the Kantian way of thinking. Addressing the importance of Bohr's views of classical concepts, it discusses how (...) his interpretation of quantum mechanics now compares with a variety of issues that have arisen only since his lifetime, including decoherence and other non-collapse arguments. Balancing historical themes with contemporary ideas, Niels Bohrs and Philosophy of Physics reveals Bohr's on-going contribution to the philosophy of science and confirms his place in the history of philosophy. (shrink)

This paper aims to contribute to the expanding discourse on inter- and transdisciplinarity. Referring to well-established distinctions in philosophy of science, the paper argues in favor of a plurality of four different dimensions: Interdisciplinarity with regard to objects, knowledge/theories, methods/practices, and further, problem perception/problem solving. Different philosophical thought traditions can be related to these distinguishable meanings. The philosophical framework of the four different dimensions will be illustrated by some of the most popular examples of research programs that are labeled interdisciplinary (...) : nanoresearch/nanoscience/nanotechnology, complex systems theory/chaos theory, biomimicry/bionics, and technology assessment/sustainability research. Thus, a minimal philosophy of science is required to understand and foster inter- and transdisciplinarity. (shrink)

The topic of this paper is the perception of properties. It is argued that the perception of properties allows for a distinction between the sense of the identity and the sense of the qualitative nature of a property. So, for example, we might perceive a property as being identical over time even though it is presented as more and more determinate. Thus, you might see an object first as red and then as crimson red. In this case, the property is (...) perceived as identical over time, even though the sense of the qualitative nature (the redness, the crimson redness) of the property is changing. The distinction between the sense of identity and the sense of quality is explicated in terms of perceiving a particular property, a trope, and perceiving it as an instance of a universal. It is subsequently argued that the perceived tropes cannot constitute the phenomenal character of the perceptual experience. (shrink)

This book reconstructs the rise and fall of Wilhelm Wundt’s fortunes, focusing for the first time on the role of Richard Avenarius as catalyst for the so-called “positivist repudiation of Wundt.” Krauss specifically looks at the progressive disavowal of Wundtian ideas in the world of scientific psychology, and especially by his former pupils. This book provides important historical context and a critical discussion of the current state of research, in addition to a detailed consideration of Wundt’s and Avenarius’ systems (...) of thought, as well as on their personal relationship. The author outlines the reception of Avenarius’ conceptions among Wundt’s pupils, such as Külpe, Münsterberg and Titchener, and among other psychologists of the time, such as Ward, James and Ebbinghaus. Finally, this book presents Wundt’s two-fold attempt to respond to the new trend through a criticism of the “materialistic” psychology, and a reformulation of his own ideas. (shrink)

The argument has been made that future generations of human beings are being harmed unjustifiably by the actions individuals commit today. This paper addresses what it might mean to harm future generations, whether we might harm them, and what our duties toward future generations might be. After introducing the Global Health Impact (GHI) concept as a unit of measurement that evaluates the effects of human actions on the health of all organisms, an incomplete theory of human justice is proposed. Having (...) shown that the negative GHIs of our current generation cause unfair harm to future generations, I argue that each human being must be allocated a fair threshold of negative GHIs that should not be exceeded. By emphasising the need to consider all the GHIs of human actions, the theory of human justice developed here is highly relevant to evaluate human actions that might affect future generations, for example those related to climate change. (shrink)

Marton ( 2019 ) argues that that it follows from the standard antirealist theory of truth, which states that truth and possible knowledge are equivalent, that knowing possibilities is equivalent to the possibility of knowing, whereas these notions should be distinct. Moreover, he argues that the usual strategies of dealing with the Church–Fitch paradox of knowability are either not able to deal with his modal-epistemic collapse result or they only do so at a high price. Against this, I argue that (...) Marton’s paper does not present any seriously novel challenge to anti-realism not already found in the Church–Fitch result. Furthermore, Edgington ( 1985 ) reformulated antirealist theory of truth can deal with his modal-epistemic collapse argument at no cost. (shrink)

The Anthropocene concept arose within the Earth System science (ESS) community, albeit explicitly as a geological (stratigraphical) time term. Its current analysis by the stratigraphical community, as a potential formal addition to the Geological Time Scale, necessitates comparison of the methodologies and patterns of enquiry of these two communities. One means of comparison is to consider some of the most widely used results of the ESS, the ‘planetary boundaries’ concept of Rockström and colleagues, and the ‘Great Acceleration’ graphs of Steffen (...) and colleagues, in terms of their stratigraphical expression. This expression varies from virtually non-existent (stratospheric ozone depletion) to pronounced and many-faceted (primary energy use), while in some cases stratigraphical proxies may help constrain anthropogenic process (atmospheric aerosol loading). The Anthropocene concepts of the ESS and stratigraphy emerge as complementary, and effective stratigraphic definition should facilitate wider transdisciplinary communication. (shrink)

In this paper, I assess Žižek ’s article “No Sex, Please, We’re Post-human!” as a provocative injunction to signal the posthuman ecstasy and deterrence. I seek to expose, rather than express, Žižek ’s posthumanist perspective as a paradoxical intertwining of different aspects of perspectivizing a post-human being from the view of the end of sexuality – the background that informs a posthuman future. Žižek ’s eluding the subject’s confrontation with the question of sexual difference to the apex of the genome (...) project touches the delicate coalescing of the notions of ‘objectivity and subjectivity’ and ‘virtuality and reality’ in the fate of the body. Ultimately, he renders this inception of this tarrying as a traumatic encounter that informs us of the existential birthright of a true posthuman. (shrink)

This chapter considers four areas in the differences between Vygotsky's concept of reason and ‘Enlightenment rationality’ in its familiar characterisation. These areas cover: (1) foundationalism and anti‐foundationalism, (2) the conception of science, (3) the conception of development and (4) idealism and materialism. The last is developed more by Ilyenkov, although, given its Hegelian and Spinozist provenance, it can be reasonably interpreted as part of the general direction of Vygotsky's work. Two indications of the importance of Hegel for understanding Vygotsky are: (...) first, the absence of an unbridgeable epistemological chasm between thought and world, and second, the conception of development as a non‐linear process embedded in historical resources. Marx's and Hegel's ideas of history and development influenced every aspect of Vygotsky's thinking on concepts. Vygotsky's work provides no blueprint for teachers and educational administrators, but it does provide a frame of ideas within which questions concerning education can fruitfully be pursued. (shrink)

We define a first-order theory FIN which has a recursive axiomatization and has the following two properties. Each finite part of FIN has finite models. FIN is strong enough to develop that part of mathematics which is used or has potential applications in natural science. This work can also be regarded as a consistency proof of this hitherto informal part of mathematics. In FIN one can count every set; this permits one to prove some new probabilistic theorems.

19 It may be suggested that, in order to justify /4's treating himself differently from others, it does not have to be the case that A necessarily has some property which everyone else necessarily lacks, i.e., that there must be a property F such that, ...

We recall the notions of weak and strong Euler characteristics on a first order structure and make explicit the notion of a Grothendieck ring of a structure. We define partially ordered Euler characteristic and Grothendieck ring and give a characterization of structures that have non-trivial partially ordered Grothendieck ring. We give a generalization of counting functions to locally finite structures, and use the construction to show that the Grothendieck ring of the complex numbers contains as a subring the ring of (...) integer polynomials in continuum many variables. We prove the existence of a universal strong Euler characteristic on a structure. We investigate the dependence of the Grothendieck ring on the theory of the structure and give a few counter-examples. Finally, we relate some open problems and independence results in bounded arithmetic to properties of particular Grothendieck rings. (shrink)

Advances in biotechnology have enabled interventions in the human organism that promise to increase physical and intellectual perform over the 'normal' or 'natural' boundary, as well as make possible targeted changes in human experience. The author investigates ethical debates surrounding these issues with a particular focus on arguments that employ a normative concept of a person in order to establish that particular interventions are permissible or impermissible. He develops an integrated model that 'maps' of the concept of a human being, (...) thereby bringing the normative elements of the concept to the fore. Nevertheless, with a view to issues of risk and justice, the author argues that anthropological arguments are only one elements of a comprehensive ethics of enhancement. (shrink)

Masaryk’s philosophical approach to reality is largely characterised by its orientation towards the positivism of Auguste Comte, which Masaryk sought to offset with the psychologism of J. S. Mill. The combination of these positivist approaches became the positive starting point for Masaryk’s ethics. But that was not the only influence on his ethics. Masaryk’s German translation of Hume’s book, titled Eine Untersuchung über die Prinzipien der Moral von David Hume (1883), reveals that the main stimuli that shaped Masaryk’s ideas about (...) ethics came from David Hume. Although the need for scientific evidence became a fundamental principle of Masaryk’s thought, the need to objectively anchor ethics in rational theism necessitated in this area a departure from his positivist outlook. Masaryk’s lectures on practical philosophy attest to this fact. The reason for his departure from a positivist stance was due to the metaphysical nature of his concept of psychology. (shrink)

This paper synthesizes confirmation by instances and confirmation by successful predictions, and thereby the Hempelian and the hypothetico-deductive traditions in confirmation theory. The merger of these two approaches is subsequently extended to the piecemeal confirmation of entire theories. It is then argued that this synthetic account makes a useful contribution from both a historical and a systematic perspective.

Extensionalist theories of the specious present suggest that every perceptual experience is extended in time for a short while, such that they are co-extensive in time with the time experienced in them. Thus, there can be no experience of time, unless the experience itself is extended in time. Accordingly, there must be something that unites the temporal parts of a perceptual experience into temporally extended wholes. I call this the “glue-problem for extensionalism”. In this paper I suggest three desiderata that (...) an extensionalist theory should meet in order to solve the glue-problem. I also distinguish between different versions of extensionalism, and argue that none of them can solve the glue-problem without violating at least one desideratum. (shrink)

This paper is a sequel to the joint publication of Scott and Krauss in which the first aspects of a mathematical theory are developed which might be called "First Order Probability Logic". No attempt will be made to present this additional material in a self-contained form. We will use the same notation and terminology as introduced and explained in Scott and Krauss, and we will frequently refer to the theorems stated and proved in the preceding paper. The main (...) objective of this study is to show that the probability of symmetric probability systems may be represented as a "weighted average" of what might be called "product probabilities". We then discuss some applications of our results to Carnap's "Principle of instantial relevance", which plays an important role in his system of inductive logic. (shrink)

The central question of this article is how to combine counterfactual theories of knowledge with the notion of actuality. It is argued that the straightforward combination of these two elements leads to problems, viz. the problem of easy knowledge and the problem of missing knowledge. In other words, there is overgeneration of knowledge and there is undergeneration of knowledge. The combination of these problems cannot be solved by appealing to methods by which beliefs are formed. An alternative solution is put (...) forward. The key is to rethink the closeness relation that is at the heart of counterfactual theories of knowledge. (shrink)

Meetings differ from ordinary conversation in that they have an agenda that specifies in advance the topics to be addressed during the meeting. However, the introduction of these topics needs to be locally accomplished and recognized by the participants as agenda items. This article presents some characteristic practices used for introducing agenda-based topics. It shows that they rely on the known-in-advance status of the items, and are presented by the chair as unilateral announcements. They exploit and invoke the written agenda (...) in several ways. The announcements are often short phrasal constructions, just citing the written title of the agenda point. Furthermore, a gaze down at the written document is used as a public display that the introduction is related to the agenda. In contrast to this practice of introducing agenda items, topics not specified by the agenda are introduced by suggestions and questions that present the introduction as contingent on acceptance by the co-participants. The analysis sheds light on the ways in which institutional talk-in-interaction is permeated by the formulations and logic of written documents. (shrink)

This paper presents the ethical nihilism that looms in the condition of sex in the posthuman. It takes over from the backdrop of Hauskeller’s description of the singularity as having a “glorious sex life.” While such a condition is heavily leaning towards hedonistic ethics, the paper critiques that it merely masks nihilistic ethics. The pleasurable picture of ‘happy rapists’ and ‘masturbatory sex’ in posthumanity with sexual affluence faces a disturbing nothingness that caters to the extreme possibility of being sexless. Following (...) from Žižek’s exposition of Houellebecq’s novel The Elementary Particles, which runs counter to Houellebecq’s later novel The Possibility of an Island, the posthuman poses paradoxes that point to a nihilistic ethical domain. Later, the paper presents two paradoxes: First, the paradox of hedonism or happiness, and second, the paradox of wealth or nothingness. (shrink)

The topic of this article is the closure of a priori knowability under a priori knowable material implication: if a material conditional is a priori knowable and if the antecedent is a priori knowable, then the consequent is a priori knowable as well. This principle is arguably correct under certain conditions, but there is at least one counterexample when completely unrestricted. To deal with this, Anderson proposes to restrict the closure principle to necessary truths and Horsten suggests to restrict it (...) to formulas that belong to less expressive languages. In this article it is argued that Horsten’s restriction strategy fails, because one can deduce that knowable ignorance entails necessary ignorance from the closure principle and some modest background assumptions, even if the expressive resources do not go beyond those needed to formulate the closure principle itself. It is also argued that it is hard to find a justification for Anderson’s restricted closure principle, because one cannot deduce it even if one assumes very strong modal and epistemic background principles. In addition, there is an independently plausible alternative closure principle that avoids all the problems without the need for restriction. (shrink)