Using new techniques for controlling the categoricity spectrum of a structure, we construct a structure with degree of categoricity but infinite spectral dimension, answering a question of Bazhenov, Kalimullin and Yamaleev. Using the same techniques, we construct a computably categorical structure of non-computable Scott rank.

We review the current knowledge concerning strong jump-traceability. We cover the known results relating strong jump-traceability to randomness, and those relating it to degree theory. We also discuss the techniques used in working with strongly jump-traceable sets. We end with a section of open questions.

We define the Scott complexity of a countable structure to be the least complexity of a Scott sentence for that structure. This is a finer notion of complexity than Scott rank: it distinguishes between whether the simplest Scott sentence is $\Sigma _{\alpha }$, $\Pi _{\alpha }$, or $\mathrm {d-}\Sigma _{\alpha }$. We give a complete classification of the possible Scott complexities, including an example of a structure whose simplest Scott sentence is $\Sigma _{\lambda + 1}$ for $\lambda $ a limit (...) ordinal. This answers a question left open by A. Miller.We also construct examples of computable structures of high Scott rank with Scott complexities $\Sigma _{\omega _1^{CK}+1}$ and $\mathrm {d-}\Sigma _{\omega _1^{CK}+1}$. There are three other possible Scott complexities for a computable structure of high Scott rank: $\Pi _{\omega _1^{CK}}$, $\Pi _{\omega _1^{CK}+1}$, $\Sigma _{\omega _1^{CK}+1}$. Examples of these were already known. Our examples are computable structures of Scott rank $\omega _1^{CK}+1$ which, after naming finitely many constants, have Scott rank $\omega _1^{CK}$. The existence of such structures was an open question. (shrink)

EveryK-trivial set is computable from an incomplete Martin-Löf random set, i.e., a Martin-Löf random set that does not compute the halting problem.

A problem is a multivalued function from a set of instances to a set of solutions. We consider only instances and solutions coded by sets of integers. A problem admits preservation of some computability-theoretic weakness property if every computable instance of the problem admits a solution relative to which the property holds. For example, cone avoidance is the ability, given a noncomputable set A and a computable instance of a problem ${\mathsf {P}}$, to find a solution relative to which A (...) is still noncomputable.In this article, we compare relativized versions of computability-theoretic notions of preservation which have been studied in reverse mathematics, and prove that the ones which were not already separated by natural statements in the literature actually coincide. In particular, we prove that it is equivalent to admit avoidance of one cone, of $\omega $ cones, of one hyperimmunity or of one non- $\Sigma ^{0}_1$ definition. We also prove that the hierarchies of preservation of hyperimmunity and non- $\Sigma ^{0}_1$ definitions coincide. On the other hand, none of these notions coincide in a nonrelativized setting. (shrink)

We introduce several highness notions on degrees related to the problem of computing isomorphisms between structures, provided that isomorphisms exist. We consider variants along axes of uniformity, inclusion of negative information, and several other problems related to computing isomorphisms. These other problems include Scott analysis (in the form of back-and-forth relations), jump hierarchies, and computing descending sequences in linear orders.

We show the existence of noncomputable oracles which are low for Demuth randomness, answering a question in [15]. We fully characterize lowness for Demuth randomness using an appropriate notion of traceability. Central to this characterization is a partial relativization of Demuth randomness, which may be more natural than the fully relativized version. We also show that an oracle is low for weak Demuth randomness if and only if it is computable.

We extend the notion of limitwise monotonic functions to include arbitrary computable domains. We then study which sets and degrees are support increasing limitwise monotonic on various computable domains. As applications, we provide a characterization of the sets S with computable increasing η-representations using support increasing limitwise monotonic sets on ℚ and note relationships between the class of order-computable sets and the class of support increasing limitwise monotonic sets on certain domains.

Humans massively depend on communication with others, but this leaves them open to the risk of being accidentally or intentionally misinformed. To ensure that, despite this risk, communication remains advantageous, humans have, we claim, a suite of cognitive mechanisms for epistemic vigilance. Here we outline this claim and consider some of the ways in which epistemic vigilance works in mental and social life by surveying issues, research and theories in different domains of philosophy, linguistics, cognitive psychology and the social sciences.

Dan Zahavi engages with classical phenomenology, philosophy of mind, and a range of empirical disciplines to explore the nature of selfhood. He argues that the most fundamental level of selfhood is not socially constructed or dependent upon others, but accepts that certain dimensions of the self and types of self-experience are other-mediated.

In his recent book ‘Kant and the Mind’ Andrew Brook makes a distinction between two types of selfawareness. The first type, which he calls empirical self-awareness, is an awareness of particular psychological states such as perceptions, memories, desires, bodily sensations etc. One attains this type of self-awareness simply by having particular experiences and being aware of them. To be in possession of empirical self-awareness is, in short, simply to be conscious of one’s occurrent experience. The second type of self-awareness he (...) calls apperceptive self-awareness. This type of self-awareness entails an awareness of oneself as the subject of experience. For this type of self-awareness to obtain, it would not be enough merely to be conscious of, say, an occurrent perception of a chair, one would also have to be aware that it was oneself who was perceiving the chair. And as Brook adds, when I am self-aware in this way, I am not only aware of being the subject of a single experience, but also aware of myself as the common subject of other psychological states (Brook, 1994: 55-57). I find Brook’s distinction illuminating, but it raises a question which I would like to pursue in this paper. When we speak of self-awareness, do we then necessarily also speak of a self, is there so to speak always a self involved in self-awareness, or is it rather the case, as Brook’s notion of empirical selfawareness might suggest, that there are types of self-awareness which are ‘selfless’, or to use two other related terms ‘subjectless’ or ‘non-egological’? Is self-awareness always to be understood as an awareness of a self, or can it be understood simply as the awareness which a specific experience has of itself? Ultimately, I believe an answer to these questions are important, both when it comes to an understanding of what exactly self-awareness amounts to, and also when it comes to a proper understanding of what a self is.. (shrink)

The aim of this volume is to discuss recent research into self-experience and its disorders, and to contribute to a better integration of the different ...

The alleged for-me-ness or mineness of conscious experience has been the topic of considerable debate in recent phenomenology and philosophy of mind. By considering a series of objections to the notion of for-me-ness, or to a properly robust construal of it, this paper attempts to clarify to what the notion is committed and to what it is not committed. This exercise results in the emergence of a relatively determinate and textured portrayal of for-me-ness as the authors conceive of it.

We show that the fact that the first player wins every instance of Galvin’s “racing pawns” game is equivalent to arithmetic transfinite recursion. Along the way we analyze the satisfaction relation for infinitary formulas, of “internal” hyperarithmetic comprehension, and of the law of excluded middle for such formulas.

The text surveys the development of the debate between Zahavi and Brough/Sokolowski regarding Husserl’s account of inner time-consciousness. The main arguments on both sides are reconsidered, and a compromise is proposed.

What does the fact that we feel shame tell us about the nature of self? Does shame testify to the presence of a self-concept, a self-ideal, and a capacity for critical self-assessment, or does it rather, as some have suggested, point to the fact that the self is in part socially constructed? Should shame primarily be classified as a self-conscious emotion, is it rather a distinct social emotion, or might this forced alternative be misguided? In the chapter, I contrast certain (...) prevalent cognitivist accounts of shame with different proposals that can be found in the phenomenological tradition and ultimately argue that prototypical forms of shame provide vivid examples of other-mediated forms of self-experience. (shrink)

The relationship of self, and self-awareness, and experience: exploring classical phenomenological analyses and their relevance to contemporary discussions in ...

The claim that the human cognitive system tends to allocate resources to the processing of available inputs according to their expected relevance is at the basis of relevance theory. The main thesis of this chapter is that this allocation can be achieved without computing expected relevance. When an input meets the input condition of a given modular procedure, it gives this procedure some initial level of activation. Input-activated procedures are in competition for the energy resources that would allow them to (...) follow their full course. What determines which of the procedures in competition get sufficient resources to trigger their full operation is the dynamics of their activation. This dynamics depend both on the prior degree of mobilisation of a modular procedure and on the activation that propagates from other active modules. It is quite conceivable also that the mobilisation of some procedures has inhibitory effects on some others. The relevance-theoretic claim is that, at every instant, this dynamics of activation provides rough physiological indicators of expected relevance. The flow of energy in the system is locally regulated by these indicators. As a result, those input-procedure combinations that have the greatest expected relevance are the more likely ones to receive sufficient energy to follow their course. (shrink)

This revised edition includes a new Preface outlining developments in Relevance Theory since 1986, discussing the more serious criticisms of the theory, and ...

The Oxford Handbook of Contemporary Phenomenology presents twenty-eight essays by some of the leading figures in the field, and gives an authoritative overview of the type of work and range of topics found and discussed in contemporary phenomenology. It is the definitive guide to what is currently going on in phenomenology, and offers a rich source of insight and stimulation for philosophers, students of philosophy, and for people working in other disciplines of the humanities, social sciences, and sciences, who are (...) interested in the state of phenomenology today. The essays explore a diverse range of topics, including intentionality, embodiment, perception, naturalism, temporality, self-consciousness, language, knowledge, ethics, politics, art and religion, and will make it clear that phenomenology, far from being a tradition of the past, is alive and in a position to make valuable contributions to contemporary thought. (shrink)

The Oxford Handbook of the History of Phenomenology contains thirty-seven new essays by leading scholars in the field. The essays all highlight historical influences, connections, and developments and provide an in-depth coverage of the development of phenomenology; one that allows for a better comprehension and assessment of the continuity as well as diversity of the phenomenological tradition. The handbook is divided into three distinct parts. The first part contains chapters that address the way phenomenology has been influenced by earlier periods (...) or figures in the history of philosophy. The second part contains chapters targeting prominent phenomenologists: How was their work affected by earlier figures, how did their own views change over time, and what kind of influence did they exert on subsequent thinkers? The contributions in the third part trace various core topics such as subjectivity, intersubjectivity, embodiment, spatiality, and imagination in the work of different phenomenologists, in order to explore how the notions were transformed, enriched, and expanded up through the century. The handbook will be a source of insight for philosophers, students of philosophy, and for people working in other disciplines of the humanities, social sciences, and sciences, who are interested in the phenomenological tradition. It is an authoritative guide to how phenomenology started, how it developed, and where it is heading. (shrink)

... Let me start my investigation by taking a brief look at the way in which self-awareness is expressed linguistically, as in the sentences "I am tired" or ...

Reason, we are told, is what makes us human, the source of our knowledge and wisdom. If reason is so useful, why didn't it also evolve in other animals? If reason is that reliable, why do we produce so much thoroughly reasoned nonsense? In their groundbreaking account of the evolution and workings of reason, Hugo Mercier and Dan Sperber set out to solve this double enigma. Reason, they argue with a compelling mix of real-life and experimental evidence, is not geared (...) to solitary use, to arriving at better beliefs and decisions on our own. What reason does, rather, is help us justify our beliefs and actions to others, convince them through argumentation, and evaluate the justifications and arguments that others address to us. In other words, reason helps humans better exploit their uniquely rich social environment. This interactionist interpretation explains why reason may have evolved and how it fits with other cognitive mechanisms. It makes sense of strengths and weaknesses that have long puzzled philosophers and psychologists--why reason is biased in favor of what we already believe, why it may lead to terrible ideas and yet is indispensable to spreading good ones.--. (shrink)

It is commonly believed that Edmund Husserl (1859-1938), well known as the founder of phenomenology and as the teacher of Heidegger, was unable to free himself from the framework of a classical metaphysics of subjectivity. Supposedly, he never abandoned the view that the world and the Other are constituted by a pure transcendental subject, and his thinking in consequence remains Cartesian, idealistic, and solipsistic. The continuing publication of Husserl’s manuscripts has made it necessary to revise such an interpretation. Drawing upon (...) both Husserl’s published works and posthumous material, Husserl’s Phenomenology incorporates the results of the most recent Husserl research. It is divided into three parts, roughly following the chronological development of Husserl’s thought, from his early analyses of logic and intentionality, through his mature transcendental-philosophical analyses of reduction and constitution, to his late analyses of intersubjectivity and lifeworld. It can consequently serve as a concise and updated introduction to his thinking. (shrink)

Millikan and Her Critics offers a unique critical discussion of Ruth Millikan's highly regarded, influential, and systematic contributions to philosophy of mind and language, philosophy of biology, epistemology, and metaphysics. These newly written contributions present discussion from some of the most important philosophers in the field today and include replies from Millikan herself.

Dan Zahavi presents a rich new study of the philosophy of Edmund Husserl, the founder of phenomenology. What kind of philosophical project was Husserl engaged in? What is ultimately at stake in so-called phenomenological analyses? In this volume Zahavi makes it clear why Husserl had such a decisive influence on 20th-century philosophy.

This essay defends a novel interpretation of the term xìng 性 as it occurs in Chinese texts of the late Warring States period (roughly 320–221 BCE). The term played an important role both in the famous controversy over the goodness or badness of people’s xìng and elsewhere in the intellectual discourse of the period. Extending especially the work of A.C. Graham, the essay stresses the importance for understanding xìng of early Chinese assumptions about spontaneity, continuity, health, and (in the human (...) case) motivation. These assumptions make xìng fundamentally different from the contemporary nature concepts with which it is often equated. In particular, people’s xìng is not a near-equivalent of human nature or (in modern Chinese) of rénxìng 人性. (shrink)

Members of a human group are bound with one another by multiple flows of information. (Here we use “information” in a broad sense that includes not only the content of people’s knowledge, but also that of their beliefs, assumptions, fictions, rules, norms, skills, maps, images, and so on.) This information is materially realized in the mental representations of the people, and in their public productions, that is, their cognitively guided behaviors and the enduring material traces of these behaviors. Mentally represented (...) information is transmitted from individuals to individuals through public productions. Public representations such as speech, gestures, writing, or pictures are a special type of public productions, the function of which is to communicate a content. Public representations play a major role in information transmission. Much information, however, is communicated implicitly, that is, without being publicly represented. Information can also be transmitted without being properly speaking communicated, not even implicitly, as when one individual acquires a skill by observing and imitating the behavior of others. Most information transmitted among humans is about local and transient circumstances, and is not transmitted beyond these. Some information of more general relevance, however, is repeatedly transmitted, and propagates throughout the group. Talk of “culture” (whatever the preferred definition or theory of culture) is about this widely distributed information and about its material realizations inside people’s mind and in their common environment (see Sperber 1996). One can study cultural phenomena in two main ways. One can interpret them, that is, try and make their contents intelligible to people of another culture, or more intelligible to members of the culture in which these phenomena occurs, as do anthropologists and historians. One may also try and explain causally how these cultural phenomena emerge, stabilize and evolve.. (shrink)

How should we appraise Bergson’s relation to phenomenology? There are different ways to tackle this question. In the following my focus will be quite narrow. I will restrict myself to a close reading of Bergson’s doctoral dissertation Essai sur les données immédiates de la conscience. The question I wish to ask is basically whether the analysis of consciousness that Bergson provides in the second chapter of the dissertation is phenomenologically convincing.

Phenomenology: The Basics is a concise and engaging introduction to one of the dominant philosophical movements of the 20th century. This lively and lucid book provides an introduction to the essential phenomenological concepts that are crucial for understanding great thinkers such as Husserl, Heidegger, and Merleau-Ponty. Written by a leading expert in the field, Dan Zahavi examines and explains key questions such as: - What is a phenomenological analysis? - What are the methodological foundations of phenomenology? - What does phenomenology (...) have to say about embodiment and intersubjectivity? - How is phenomenology distinguished from, and related to, other fields in philosophy? - How do ideas from classic phenomenology relate to ongoing debates in psychology and qualitative research? With a glossary of key terms and suggestions for further reading, the book considers key philosophical arguments around phenomenology, making this an ideal starting point for anyone seeking a concise and accessible introduction to the rich and complex study of phenomenology. (shrink)

We examine the sequences A that are low for dimension, i.e. those for which the effective dimension relative to A is the same as the unrelativized effective dimension. Lowness for dimension is a weakening of lowness for randomness, a central notion in effective randomness. By considering analogues of characterizations of lowness for randomness, we show that lowness for dimension can be characterized in several ways. It is equivalent to lowishness for randomness, namely, that every Martin-Löf random sequence has effective dimension (...) 1 relative to A, and lowishness for K, namely, that the limit of KA/K is 1. We show that there is a perfect [Formula: see text]-class of low for dimension sequences. Since there are only countably many low for random sequences, many more sequences are low for dimension. Finally, we prove that every low for dimension is jump-traceable in order nε, for any ε > 0. (shrink)

Cybernetically enhanced humanoids, the Borg assimilate entire civilizations using advanced technology. Genocidal destroyers, the Borg's ultimate goal is perfecting their species through the imperialistic incorporation of other species‘ biological and technological distinctiveness. Anxieties about the Borg focus on their invincible militarism, genocidal threat, ruthless cruelty, totalitarian collectivism, torturous technology, and physical monstrousness. The philosophical assumptions that underlie transhumanism can be traced to French philosopher Ren'e Descartes, who provided the foundation for Enlightenment philosophy and scientific advancement. The perfectionist goal of the (...) transhumanist project might lead to discrimination against those not wealthy enough to afford the genetic and cybernetic enhancements that become available. The fundamental philosophical premise that makes the Borg collective consciousness possible is shared by transhumanism: thoughts, memories, and personality traits are reducible to patterns of neural energy in the brain, and these patterns can be electronically simulated, transmitted, changed, or controlled. (shrink)

LetEbe a computably enumerable equivalence relation on the setωof natural numbers. We say that the quotient set$\omega /E$realizesa linearly ordered set${\cal L}$if there exists a c.e. relation ⊴ respectingEsuch that the induced structure is isomorphic to${\cal L}$. Thus, one can consider the class of all linearly ordered sets that are realized by$\omega /E$; formally,${\cal K}\left = \left\{ {{\cal L}\,|\,{\rm{the}}\,{\rm{order}}\, - \,{\rm{type}}\,{\cal L}\,{\rm{is}}\,{\rm{realized}}\,{\rm{by}}\,E} \right\}$. In this paper we study the relationship between computability-theoretic properties ofEand algebraic properties of linearly ordered sets realized (...) byE. One can also define the following pre-order$ \le _{lo} $on the class of all c.e. equivalence relations:$E_1 \le _{lo} E_2 $if every linear order realized byE1is also realized byE2. Following the tradition of computability theory, thelo-degrees are the classes of equivalence relations induced by the pre-order$ \le _{lo} $. We study the partially ordered set oflo-degrees. For instance, we construct various chains and anti-chains and show the existence of a maximal element among thelo-degrees. (shrink)