For a computable structure $\mathcal {M}$, the categoricity spectrum is the set of all Turing degrees capable of computing isomorphisms among arbitrary computable copies of $\mathcal {M}$. If the spectrum has a least degree, this degree is called the degree of categoricity of $\mathcal {M}$. In this paper we investigate spectra of categoricity for computable rigid structures. In particular, we give examples of rigid structures without degrees of categoricity.

We investigate effective categoricity for polymodal algebras. We prove that the class of polymodal algebras is complete with respect to degree spectra of nontrivial structures, effective dimensions, expansion by constants, and degree spectra of relations. In particular, this implies that every categoricity spectrum is the categoricity spectrum of a polymodal algebra.

Defining the degree of categoricity of a computable structure ${\mathcal{M}}$ to be the least degree d for which ${\mathcal{M}}$ is d-computably categorical, we investigate which Turing degrees can be realized as degrees of categoricity. We show that for all n, degrees d.c.e. in and above 0 (n) can be so realized, as can the degree 0 (ω).

Review by: Alexander G. Melnikov The Bulletin of Symbolic Logic, Volume 19, Issue 3, Page 400-401, September 2013.

An explicit categorical equivalence is defined between a proper subvariety of the class of \-algebras, as defined by Di Nola and Dvurečenskij, to be called \-algebras, and the category of semi-low \-rings. This categorical representation is done using the prime spectrum of the \-algebras, through the equivalence between \-algebras and \-groups established by Mundici, from the perspective of the Dubuc–Poveda approach, that extends the construction defined by Chang on chains. As a particular case, semi-low \-rings associated to Boolean algebras (...) are characterized. (shrink)

An explicit categorical equivalence is defined between a proper subvariety of the class of \-algebras, as defined by Di Nola and Dvurečenskij, to be called \-algebras, and the category of semi-low \-rings. This categorical representation is done using the prime spectrum of the \-algebras, through the equivalence between \-algebras and \-groups established by Mundici, from the perspective of the Dubuc–Poveda approach, that extends the construction defined by Chang on chains. As a particular case, semi-low \-rings associated to Boolean algebras (...) are characterized. (shrink)

We investigate the complexity of embeddings between bi-embeddable structures. In analogy with categoricity spectra, we define the bi-embeddable categoricity spectrum of a structure A as the family of Turing degrees that compute embeddings between any computable bi-embeddable copies of A; the degree of bi-embeddable categoricity of A is the least degree in this spectrum (if it exists). We extend many known results about categoricity spectra to the case of bi-embeddability. In particular, we exhibit structures (...) without degree of bi-embeddable categoricity, and we show that every degree d.c.e above 0(α) for α a computable successor ordinal and 0(λ) for λ a computable limit ordinal is a degree of bi-embeddable categoricity. We also give examples of families of degrees that are not bi-embeddable categoricity spectra. (shrink)

We develop a general covariant categorical modeling theory of natural systems’ behavior based on the fundamental functorial processes of representation and localization-globalization. In the first part of this study we analyze the process of representation. Representation constitutes a categorical modeling relation that signifies the semantic bidirectional process of correspondence between natural systems and formal symbolic systems. The notion of formal systems is substantiated by algebraic rings of observable attributes of natural systems. In this perspective, the distinction between simple and complex (...) systems is reflected in the appropriate qualification of their corresponding rings of observables. The crucial distinguishing requirement with respect to the coordinatizing rings of observables has to do with the property of global commutativity. The global information structure representing the behavior of a complex system is modeled functorially in terms of its Spectrum functor. Due to the fact that, the fundamental process of representation is bidirectional by construction, it admits a precise categorical formulation in terms of the syntactic language of adjoint functors, constituting thus, a categorical adjunction. The left adjoint functor of this adjunction signifies the process of encoding the information related with phenomena of natural systems in terms of coordinatizing rings of observables, whereas, the right adjoint functor signifies the inverse process of information decoding, which, can be used for making predictions about the behavior of natural systems. (shrink)

We develop a general covariant categorical modeling theory of natural systems' behavior based on the fundamental functorial processes of representation and localization-globalization. In the second part of this study we analyze the semantic bidirectional process of localization-globalization. The notion of a localization system of a complex information structure bears a dual role: Firstly, it determines the appropriate categorical environment of base reference contexts for considering the operational modeling of a complex system's behavior, and secondly, it specifies the global compatibility conditions (...) of local contextual information. A localization system acts on the global information structure of a complex system, partitions it into sorts, and eventually, forces the consistent sheaf-theoretic fibering of the latter over the base category of commutative reference contexts. In this manner, the sheafification of the Spectrum functor of a complex information structure takes place by imposing on the uniform and homologous fibered structure of elements of the Spectrum presheaf the following two requirements of coherence in relation to the localization-globalization process: [i]. Compatibility of information under restriction from the global to the local level, and [ii]. Compatibility of information under extension from the local to the global level. Correspondingly, the options of local and global receive a concrete mathematical meaning with respect to a suitable notion of topology (categorical Grothendieck topology) defined on the base category of commutative reference contexts. Finally, the accurate functorial process modeling of a complex system's behavior, respecting the processes of representation and localization-globalization, is being effectuated by means of establishing a categorical dual equivalence between the category of complex information structures, and the topes of sheaves over the base category of partial or local information carriers, equipped with the categorical topology of epimorphosis families. (shrink)

This paper has two main aims. The first is to present a general approach for understanding “dispositional” and “categorical” properties; the second aim is to use this approach to criticize Russellian Monism. On the approach I suggest, what are usually thought of as “dispositional” and “categorical” properties are really just the extreme ends of a spectrum of options. The approach allows for a number of options between these extremes, and it is plausible, I suggest, that just about everything of (...) scientific interest falls in this middle ground. I argue that Russellian Monism depends for its plausibility on the unarticulated assumption that there are no properties in the middle ground. (shrink)

We describe a strongly minimal theory S in an effective language such that, in the chain of countable models of S, only the second model has a computable presentation. Thus there is a spectrum of an -categorical theory which is neither upward nor downward closed. We also give an upper bound on the complexity of spectra.

ABSTRACT Controlled human infection (CHI) models have been developed for numerous pathogens in order to better understand disease processes and accelerate drug and vaccine testing. In the past, some researchers conducted highly controversial CHIs with vulnerable populations, including children. Ethical frameworks for CHIs now recommend vulnerable populations be excluded because they cannot consent to high risk research. In this paper we argue that CHI studies span a wide spectrum of benefit and risk, and that some CHI studies may involve (...) minimal risk. The categorical exclusion of children from CHIs therefore departs from the standard approach to evaluating research risks, as international regulations and ethical guidance for pediatric research generally permit non‐beneficial research with low risks. The paradigm in research ethics has also shifted from focusing on protecting vulnerable participants to recognizing that inclusion can be important as a matter of justice, providing new reasons to question this default exclusion of children from CHIs. Recognizing that pediatric CHIs can raise complex ethical issues and are easy to sensationalize in ways that may threaten the public’s trust in research and sponsor institutions, we conclude by describing additional complexities that must be addressed before pediatric CHIs beyond licensed vaccine studies might be ethically acceptable. (shrink)

A computable structure $\mathcal {A}$ is $\mathbf {x}$-computably categorical for some Turing degree $\mathbf {x}$ if for every computable structure $\mathcal {B}\cong\mathcal {A}$ there is an isomorphism $f:\mathcal {B}\to\mathcal {A}$ with $f\leq_{T}\mathbf {x}$. A degree $\mathbf {x}$ is a degree of categoricity if there is a computable structure $\mathcal {A}$ such that $\mathcal {A}$ is $\mathbf {x}$-computably categorical, and for all $\mathbf {y}$, if $\mathcal {A}$ is $\mathbf {y}$-computably categorical, then $\mathbf {x}\leq_{T}\mathbf {y}$. We construct a $\Sigma^{0}_{2}$ set whose (...) degree is not a degree of categoricity. We also demonstrate a large class of degrees that are not degrees of categoricity by showing that every degree of a set which is 2-generic relative to some perfect tree is not a degree of categoricity. Finally, we prove that every noncomputable hyperimmune-free degree is not a degree of categoricity. (shrink)

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.

Alex has written an excellent thesis in the area of computable model theory. The latter is a subject that nicely combines model-theoretic ideas with delicate recursiontheoretic constructions. The results demand good knowledge of both fields. In his thesis, Alex begins by reviewing the essential model-theoretic facts, especially the Baldwin-Lachlan result about uncountably categorical theories. This he follows with a brief discussion of recursion theory, including mention of the priority method. The deepest part of the thesis concerns the study of the (...) recursive spectrum of an uncountably categorical theory, i.e. the set of n ≤ ! such that the n-th model of the theory (in the Baldwin-Lachlan sense) has a computable presentation. This is a deep and very active area of conteporary research in computable model theory which Alex discusses in considerable detail. The exposition is very good and therefore the thesis makes a nice introduction to the subject for a wide community of logicians. (Sy-David Friedman, Professor of Mathematical Logic, Director of the Kurt Godel Research Center for Mathematical Logic, University of Vienna). (shrink)

The question has been raised whether Nietzsche intends eternal recurrence to be like a categorical imperative. The obvious objection to understanding eternal recurrence as like a categorical imperative is that for a categorical imperative to make any sense, for moral obligation to make any sense, it must be possible for individuals to change themselves. And Nietzsche denies that individuals can change themselves. Magnus thinks the determinism “implicit in the doctine of the eternal recurrence of the same renders any imperative impotent…. (...) How can one will what must happen in any case?” At the other end of the spectrum, those who do hold that eternal recurrence is like a categorical imperative, for their part, tend to ignore or deny the determinism involved in eternal recurrence. This article explores the extent to which it can be claimed that eternal recurrence is like a categorical imperative without downplaying Nietzsche's dterminism. (shrink)

The question has been raised whether Nietzsche intends eternal recurrence to be like a categorical imperative. The obvious objection to understanding eternal recurrence as like a categorical imperative is that for a categorical imperative to make any sense, for moral obligation to make any sense, it must be possible for individuals to change themselves. And Nietzsche denies that individuals can change themselves. Magnus thinks the determinism “implicit in the doctine of the eternal recurrence of the same renders any imperative impotent…. (...) How can one will what must happen in any case?” At the other end of the spectrum, those who do hold that eternal recurrence is like a categorical imperative, for their part, tend to ignore or deny the determinism involved in eternal recurrence. This article explores the extent to which it can be claimed that eternal recurrence is like a categorical imperative without downplaying Nietzsche's dterminism. (shrink)

Rosen's modelling relations constitute a conceptual schema for the understanding of the bidirectional process of correspondence between natural systems and formal symbolic systems. The notion of formal systems used in this study refers to information structures constructed as algebraic rings of observable attributes of natural systems, in which the notion of observable signifies a physical attribute that, in principle, can be measured. Due to the fact that modelling relations are bidirectional by construction, they admit a precise categorical formulation in terms (...) of the category-theoretic syntactic language of adjoint functors, representing the inverse processes of information encoding/decoding via adjunctions. As an application, we construct a topological modelling schema of complex systems. The crucial distinguishing requirement between simple and complex systems in this schema is reflected with respect to their rings of observables by the property of global commutativity. The global information structure representing the behaviour of a complex system is modelled functorially in terms of its spectrum functor. An exact modelling relation is obtained by means of a complex encoding/decoding adjunction restricted to an equivalence between the category of complex information structures and the category of sheaves over a base category of partial or local information carriers equipped with an appropriate topology. (shrink)

BackgroundThere is much overlap among the symptomology of autistic spectrum disorders, obsessive compulsive disorders, and alexithymia, which all typically involve impaired social interactions, repetitive impulsive behaviors, problems with communication, and mental health.AimThis study aimed to identify direct and indirect associations among alexithymia, OCD, cardiac interoception, psychological inflexibility, and self-as-context, with the DV ASD and depression, while controlling for vagal related aging.MethodologyThe data involved electrocardiogram heart rate variability and questionnaire data. In total, 1,089 participant's data of ECG recordings of healthy (...) resting state HRV were recorded and grouped into age categories. In addition to this, another 224 participants completed an online survey that included the following questionnaires: Yale-Brown Obsessive Compulsive Scale ; Toronto Alexithymia Scale 20 ; Acceptance and Action Questionnaire ; Depression, Anxiety, and Stress Scale 21 ; Multi-dimensional Assessment of Interoceptive Awareness Scale ; and the Self-as-Context Scale.ResultsHeart rate variability was shown to decrease with age when controlling for BMI and gender. In the two SEMs produced, it was found that OCD and alexithymia were causally associated with autism and depression indirectly through psychological inflexibility, SAC, and ISen interoception.ConclusionThe results are discussed in relation to the limitations of the DSM with its categorical focus of protocols for syndromes and provide support for more flexible ideographic approaches in diagnosing and treating mental health and autism within the Extended Evolutionary Meta-Model. Graph theory approaches are discussed in their capacity to depict the processes of change potentially even at the level of the relational frame. (shrink)

Lying is a common phenomenon amongst human beings. It seems to play a role in making social interactions run more smoothly. Too much honesty can be regarded as impolite or downright rude. Remarkably, lying is not a common phenomenon amongst normally intelligent human beings who are on the autism spectrum. They appear to be ‘attractively morally innocent’ and seem to have an above average moral conscientious objection against deception. In this paper, the behavior of persons with autism with regard (...) to deception and truthfulness will be discussed in the light of two different ethical theories, illustrated by fragments from autobiographies of persons with autism. A systemizing ‘Kantian’ and an empathizing ‘ethics of care’ perspective reveal insights on high-functioning autism, truthfulness and moral behavior. Both perspectives are problematic from the point of view of a moral agent with autism. High-functioning persons with autism are, generally speaking, strong systemizes and weak empathizers. Particularly, they lack ‘cognitive empathy’ which would allow them to understand the position of the other person. Instead, some tend to invent a set of rules that makes their behavior compatible with the expectations of others. From a Kantian point of view, the autistic tendency to always tell the truth appears praiseworthy and should not be changed, though it creates problems in the social life of persons with autism. From a care ethics perspective, on the other hand, a way should be found to allow the high-functioning persons with autism to respect the feelings and needs of other persons as sometimes overruling the duty of truthfulness. We suggest this may even entail ‘morally educating’ children and adolescents with autism to become socially skilled empathic ‘liars’. (shrink)

Prospective follow-up studies have shown that even though some children outgrow the disorder, a childhood diagnosis of attention deficit hyperactivity disorder is clearly a risk factor for a broad range of adverse outcomes, with extremes including drug abuse and juvenile delinquency. This article considers the use of several spectrum concepts and some neuroethical issues. It provides a list of criterion symptoms with a threshold set for the number of symptoms required for categorical diagnoses of disorders. It gives a brief (...) review of some brain imaging and pharmacological treatment studies of ADHD to set the stage for a consideration of brain-specific issues related to neuroethics. Studies using reaction time tasks of cognitive control, response inhibition, and conflict have identified interindividual variance in task performance as one of the most prominent aspects of cognitive deficits related to ADHD. (shrink)

ABSTRACTAnxiety and depression diagnoses are associated with suicidal thoughts and behaviours. However, a categorical understanding of these associations limits insight into identifying dimensional mechanisms of suicide risk. This study investigated anxious and depressive features through a lens of suicide risk, independent of diagnosis. Latent class analysis of 97 depression, anxiety, and suicidality-related items among 616 psychiatric outpatients indicated a 3-class solution, specifically: a higher suicide-risk class uniquely differentiated from both other classes by high reported levels of depression and anxious arousal; (...) a lower suicide-risk class that reported levels of anxiety sensitivity and generalised worry comparable to Class 1, but lower levels of depression and anxious arousal; and a low to non-suicidal class that reported relatively low levels across all depression and anxiety measures. Discriminants of the higher suicide-risk class included borderline personality disorder; report... (shrink)

The spectrum of a relation on a computable structure is the set of Turing degrees of the image of R under all isomorphisms between and any other computable structure . The relation is intrinsically computably enumerable if its image under all such isomorphisms is c.e. We prove that any computable partially ordered set is isomorphic to the spectrum of an intrinsically c.e. relation on a computable structure. Moreover, the isomorphism can be constructed in such a way that the (...) image of the minimum element of the partially ordered set is computable. This solves the spectrum problem. The theorem and modifications of its proof produce computably categorical structures whose expansions by finite number of constants are not computably categorical and, indeed, ones whose expansions can have any finite number of computable isomorphism types. They also provide examples of computably categorical structures that remain computably categorical under expansions by constants but have no Scott family. (shrink)

Results of R. Miller in 2009 proved several theorems about algebraic fields and computable categoricity. Also in 2009, A. Frolov, I. Kalimullin, and R. Miller proved some results about the degree spectrum of an algebraic field when viewed as a subfield of its algebraic closure. Here, we show that the same computable categoricity results also hold for finite-branching trees under the predecessor function and for connected, finite-valence, pointed graphs, and we show that the degree spectrum results (...) do not hold for these trees and graphs. We also offer an explanation for why the degree spectrum results distinguish these classes of structures: although all three structures are algebraic structures, the fields are what we call effectively algebraic. (shrink)

Moral criticism sometimes takes the form of asking: What if everyone acted the way you do? Such criticism seems to be grounded in some form of moral reasoning, which has in the past been the aim of various efforts of clarification, refutation and defense, in the guise of interpretations of Kant's Categorical Imperative as well as in Analytic Ethics. The book forms the first monographic attempt since decades to establish systematic order among contributions to the field. It examines a wide (...) spectrum of generalization procedures with respect to the plausibility of their outputs, analyses their shortcomings and arrives at novel results. (shrink)

The Posthuman offers both an introduction and major contribution to contemporary debates on the posthuman. Digital 'second life', genetically modified food, advanced prosthetics, robotics and reproductive technologies are familiar facets of our globally linked and technologically mediated societies. This has blurred the traditional distinction between the human and its others, exposing the non-naturalistic structure of the human. The Posthuman starts by exploring the extent to which a post-humanist move displaces the traditional humanistic unity of the subject. Rather than perceiving this (...) situation as a loss of cognitive and moral self-mastery, Braidotti argues that the posthuman helps us make sense of our flexible and multiple identities. Braidotti then analyzes the escalating effects of post-anthropocentric thought, which encompass not only other species, but also the sustainability of our planet as a whole. Because contemporary market economies profit from the control and commodification of all that lives, they result in hybridization, erasing categorical distinctions between the human and other species, seeds, plants, animals and bacteria. These dislocations induced by globalized cultures and economies enable a critique of anthropocentrism, but how reliable are they as indicators of a sustainable future? The Posthuman concludes by considering the implications of these shifts for the institutional practice of the humanities. Braidotti outlines new forms of cosmopolitan neo-humanism that emerge from the spectrum of post-colonial and race studies, as well as gender analysis and environmentalism. The challenge of the posthuman condition consists in seizing the opportunities for new social bonding and community building, while pursuing sustainability and empowerment. (shrink)

The current assessment of behaviors in the inventories to diagnose autism spectrum disorders (ASD) focus on observation and discrete categorizations. Behaviors require movements, yet measurements of physical movements are seldom included. Their inclusion however, could provide an objective characterization of behavior to help unveil interactions between the peripheral and the central nervous systems. Such interactions are critical for the development and maintenance of spontaneous autonomy, self-regulation and voluntary control. At present, current approaches cannot deal with the heterogeneous, dynamic and (...) stochastic nature of development. Accordingly, they leave no avenues for real-time or longitudinal assessments of change in a coping system continuously adapting and developing compensatory mechanisms. We offer a new unifying statistical framework to reveal re-afferent kinesthetic features of the individual with ASD. The new methodology is based on the non-stationary stochastic patterns of minute fluctuations (micro-movements) inherent to our natural actions. Such patterns of behavioral variability provide re-entrant sensory feedback contributing to the autonomous regulation and coordination of the motor output. From an early age, this feedback supports centrally driven volitional control and fluid, flexible transitions between intentional and spontaneous behaviors. We show that in ASD there is a disruption in the maturation of this form of proprioception. Despite this disturbance, each individual has unique adaptive compensatory capabilities that we can unveil and exploit to evoke faster and more accurate decisions. Measuring the kinesthetic re-afference in tandem with stimuli variations we can detect changes in their micro-movements indicative of a more predictive and reliable kinesthetic percept. Our methods address the heterogeneity of ASD with a personalized approach grounded in the inherent sensory-motor abilities that the individual has already developed. (shrink)

We initiate a systematic investigation of the abstract elementary classes that have amalgamation, satisfy tameness, and are stable in some cardinal. Assuming the singular cardinal hypothesis, we prove a full characterization of the stability cardinals, and connect the stability spectrum with the behavior of saturated models.We deduce that if a class is stable on a tail of cardinals, then it has no long splitting chains. This indicates that there is a clear notion of superstability in this framework.We also present (...) an application to homogeneous model theory: for [Formula: see text] a homogeneous diagram in a first-order theory [Formula: see text], if [Formula: see text] is both stable in [Formula: see text] and categorical in [Formula: see text] then [Formula: see text] is stable in all [Formula: see text]. (shrink)

Business, management, and business ethics literature pay little attention to the topic of AI robots. The broad spectrum of potential ethical issues pertains to using driverless cars, AI robots in care homes, and in the military, such as Lethal Autonomous Weapon Systems. However, there is a scarcity of in-depth theoretical, methodological, or empirical studies that address these ethical issues, for instance, the impact of morality and where accountability resides in AI robots’ use. To address this dearth, this study offers (...) a conceptual framework that interpretively develops the ethical implications of AI robot applications, drawing on descriptive and normative ethical theory. The new framework elaborates on how the locus of morality and moral intensity combine within context-specific AI robot applications, and how this might influence accountability thinking. Our theorization indicates that in situations of escalating AI agency and situational moral intensity, accountability is widely dispersed between actors and institutions. ‘Accountability clusters’ are outlined to illustrate interrelationships between the locus of morality, moral intensity, and accountability and how these invoke different categorical responses: illegal, immoral, permissible, and supererogatory pertaining to using AI robots. These enable discussion of the ethical implications of using AI robots, and associated accountability challenges for a constellation of actors—from designer, individual/organizational users to the normative and regulative approaches of industrial/governmental bodies and intergovernmental regimes. (shrink)

According to proponents of the continuity hypothesis, metaphors represent one end of a spectrum of linguistic phenomena, which includes various forms of loosening/broadening, such as category extensions and approximations, as well as hyperbolic interpretations. The continuity hypothesis is used to establish that the inferences derived from the set of linguistic expressions mentioned above result from the same or nearly similar pragmatic processes. In this paper, we want to challenge that particular aspect of the continuity hypothesis. We do so based (...) on considerations and analysis of an understudied linguistic phenomenon that we call the metaphorical uses of proper names (MPNs). We first explain how MPNs represent a unique linguistic class distinguishable from, for example, nicknames. In addition, we offer some remarks on how MPNs can be understood against the background of current debates between referentialists and predicativists about names. Our discussion leads us to conclude that MPNs are categorically different from literal interpretations of proper names. We spell out the consequences that the results of our analysis have for the continuity hypothesis. (shrink)

Chapter 1 First Person Access to Mental States. Mind Science and Subjective Qualities -/- Abstract. The philosophy of mind as we know it today starts with Ryle. What defines and at the same time differentiates it from the previous tradition of study on mind is the persuasion that any rigorous approach to mental phenomena must conform to the criteria of scientificity applied by the natural sciences, i.e. its investigations and results must be intersubjectively and publicly controllable. In Ryle’s view, philosophy (...) of mind needs to adopt an antimentalist stance to achieve this aim. Antimentalism not only definitively rejects the idea that mind is a substance separated from the body, it also denies that mental phenomena radically differ from physical phenomena by virtue of several unique features. Most problematically, mental phenomena have a conscious character (mental states are related to specific qualitative feelings) and are accessible only to the first-person (only the subject knows directly what s/he is experiencing inside his/her mind). Ryle takes a strong stance on antimentalism going so far as to maintain that an approach to mind which aims to meet the criteria of scientificity set by the natural sciences must avoid any reference to internal, unobservable mental states. In his view (which is considered a specifically philosophical version of psychological behaviorism and also addresses questions put forward in psychological research), mental states can be redescribed in terms of behavioral dispositions. In this chapter, we address the historical roots of the antimentalist view and analyze its relation to the later tradition of research on mind. We show that, compared to the antimentalist stance, functionalism and cognitivism take a step back when they maintain that direct reference to mental states is necessary since mental states cause and therefore explain human behavior. This step backwards is often interpreted as a return to mentalism. However, this is only partially true. Indeed, we suggest that these later traditions retain one important element of Ryle’s antimentalism, i.e. the idea that mental states must be uniquely identified using external and publicly observable criteria, while excluding any reference to introspection and those qualitative dimensions of a mental state, which are accessible only to the first-person. According to the perspective we put forward, this epistemological stance has continued to influence contemporary research on mind and current philosophical and psychological theories which both tend to exclude the subjective qualities of human experience from their accounts of how the mind works. The issue we raise here is whether this is legitimate or whether subjective qualities do play a role with respect to the way our mind works. The conclusion of this chapter anticipates the argument the book makes in in favor of this latter position, starting from a particular angle, i.e. the problem of how we categorize concepts related to our internal states. -/- Chapter 2 The Misleading Aspects of the Mind/Computer Analogy. The Grounding Problem and the Thorny Issue of Propriosensitive Information -/- Abstract. After the crisis of behaviorism, cognitivism and functionalism became the predominant models in the field of psychology and of philosophy, respectively. Their success is mainly due to the new key they use for interpreting mental processes: the mind/computer analogy. On the basis of this analogy, mental operations are seen as cognitive processes based on computations, i.e. on manipulations of abstract symbols which are in turn understood as informational unities (representations). This chapter identifies two main problems with this model. The first is how these symbols can relate to and communicate with perception and thus allow us to identify and classify what we perceive through the senses. Here we limit ourselves to presenting this issue in relation to the classical symbol grounding problem originally put forward by Harnad on the basis of Searle’s Chinese room argument. An attempt to address the problem raised here will be made in chap. 3. The second point we discuss in relation to the mind/computer analogy concerns the idea of information it fosters. Indeed, following this analogy, information is something available in the external world which can be captured by the senses and transmitted to the central system without being influenced or modified by the procedures of transmission. This perspective does not take into account that – unlike computers – in living beings information is acquired by means of the body. As Ulric Neisser has already pointed out, the body is itself an informational source that provides us with additional sensory experience that influences (modifies or complements) the information extracted from the external world by the senses. To develop this line of analysis and to determine exactly what information is provided by the body and how this might influence cognition, we examine Sherrington’s and Gibson’s positions. Moving on from their views, we qualify bodily information in terms of ‘proprioception’. We use ‘proprioception’ in a broad sense to describe any kind of experience we have of our internal states (including postural information as well as sensations related to the general state of the body and its parts). Following Damasio’s and Craig’s studies, we further elaborate this position, arguing that living beings are equipped with an internal propriosensitive monitoring system which maps all the changes that constantly occur in our body and that give us perceptual (‘proprioceptive’ or propriosensitive) information about what happens inside us. Moreover, relying on Goldie’s and Ratcliffe’s view, we show that emotional information can also be considered as a form of ‘proprioception’ which contributes to determining everything we perceive. This analysis leads us to the second main thesis of this book: ‘proprioception’ is a form of internal perception and it is an essential component of the sensory information we can access and use for all cognitive purposes. -/- Chapter 3 Semantic Competence from the Inside: Conceptual Architecture and Composition -/- Abstract. Concepts are essential constituents of thought: they are the instruments we use to categorize our experience, i.e. to classify things and group them together in homogeneous sets. Here we define concepts as the internal mental information (representations) that allows us, among other things, to master words in natural language. By analyzing the way in which individuals master word meanings we explore a number of hypotheses regarding the nature of concepts. Following Diego Marconi’s research, we differentiate between two kind of abilities that underpin lexical competence – so-called ‘referential’ and ‘inferential competence’ – and we suggest that, in order to support these abilities, concepts must also include two corresponding kinds of information, i.e. inferential and referential information. We point out that the most widely used and acknowledged theories of concepts do not make this distinction, instead broadly characterizing the information used for categorization in terms of propositionally described feature lists. However, we show that while feature lists can explain inferential competence, they do not account for referential competence. To address the issue of referential competence we examine Ray Jackendoff’s hypothesis that to account for the possibility of linking perceptual and conceptual information we need to assume the existence of a (visual) representation that encodes the geometric and topological properties of objects and bridges the gap between the percept and the concept. Furthermore, we analyze the extension of this work by Jesse Prinz who introduced the notion of a proxytype, a perceptual representation of a class of objects that incorporates structural and parametric information related to their appearance. However, as we point out, proxytypes can only explain the relationship between perception and concepts with respect to instances that can be perceived through the senses and that belong to the same class by virtue of their physical similarity. We suggest that this notion be extended to include larger conceptual classes. To accomplish this, we further develop Mark Johnson, George Lakoff and Jean Mandler’s idea of a schematic image and argue that conceptual representations include a perceptual schema. Perceptual schemata are non-linguistic, structured experiential gestalts (patterns or maps) that make use of information taken from all sensory modalities, including body perception. They accomplish a quasi-conceptual function: they allow us to recognize and to classify different instances. In this work, we hypothesize that perceptual schemata are an essential component of concepts, but not identical to them. Instead, we suggest that concepts include both perceptual and propositional information with perceptual schemata providing the ‘perceptual core concept’ that grounds related propositional information. -/- Chapter 4 In the Beginning There Were Categories. The Bodily Origin of Prelinguistic Categorical Organization: The Example of Folkbiological Taxonomies -/- Abstract. Studies of categorization in psychology and the cognitive sciences have made use of the notions of ‘category’ and ‘concept’ without precisely defining what is meant by either; in fact, often these terms have been used as synonyms, making it difficult to address specific issues related to conceptual development. This chapter begins by discussing the definitions of, as well as the distinctions between, ‘categories’ and ‘concepts’ in the classical philosophical tradition (Aristotle, Kant and Husserl). We introduce our view of categories with reference to Husserl. Categorization is defined as the way in which our experience is originally (pre-linguistically) organized in a passive and fully unconscious manner on the basis of universal structuring principles. Conceptualization is explained as a later process in which the earlier categorical macro-classes are further subdivided into more specific and detailed sets; this later process also relies on linguistic learning and exposure to culture. On the basis of Ray Jackendoff, Jean Mandler, George Lakoff and Mark Johnson’s work, we hypothesize that categorization is a two-step process that begins with the formation of homogeneous sets of entities partitioned into regions that describe the ontological boundaries of the objects that humans perceive (categories) and continues at a later stage with the development of more specific classifications (concepts). In this chapter, we mainly address three related issues: Why should we assume that there is categorical organization which precedes the development of a conceptual system? How do categories and concepts relate to each other? Shall we hypothesize that categories are innate or that they are formed before concepts on the basis of information and organizational structure available at a very early developmental stage? We show that categorical partitions are necessary for categorization and, following Mandler, that the general categories we form at an early age do not match our adult superordinate concepts. As for the third issue, we argue that there might be no need to assume that categories are innately present in the human mind, since their formation can be explained – at least in certain cases – by basic mechanisms that work on body (propriosensitive) information. This hypothesis will not be discussed in general, but in relation to a particularly relevant example of categorical partition, i.e. the folk-biological dichotomy between ANIMATE/INANIMATE. This is compared with other dichotomies that derive from it, but are not directly categorical such as LIVING/NON-LIVING and BIOLOGICAL/NON-BIOLOGICAL. -/- Chapter 5 Internal States: From Headache to Anger. Conceptualization and Semantic Mastery -/- Abstract. Here we ask if we can also apply the distinction between referential and inferential competence we introduced in Chapter 3 to words that do not refer to things that are perceived using the external senses, especially to words/concepts that denote bodily experiences (such as pain, thirst, hunger, etc.) or emotions. We introduce and discuss the hypothesis that – even though such words/concepts do not refer to intersubjectively identifiable entities in the external world – they do have a kind of referent that can be accessed via direct perception, more specifically ‘proprioception’, as we have defined it in terms of all propriosensitive information we can consciously access. In the first part of the chapter, we specifically consider terms denoting bodily experiences such as ‘pain’ or ‘hunger’ and argue that their referents are identified and classified from a first-personal point of view on the basis of four main characteristics: their specific intensity, their localization in the body, their co-occurrence with other signals and above all their specific qualitative sensations. Emotions are addressed in the second part of the chapter. We suggest that there is a continuity between bodily experiences and emotions. In particular, we argue for a perceptual theory of emotions in line with that proposed by James and Lange at the end of the 19th century and developed more recently by authors such as Damasio (see also chap. 2§5, §6). The hypothesis we put forward is that the referential information that supports the categorization of emotions and therefore also our mastery of terms referring to emotions consists in the perception (i.e. the ‘proprioception’) of those bodily states and changes in bodily states which constitute our emotional experience. In the context of this discussion we examine some objections to this line of reasoning that arise from a cognitivist perspective and following authors such as Oatley, Johnson-Laird and Frijda, we distinguish between basic emotions that can be identified and classified solely on the basis on how they feel and complex emotions whose identification and classification additionally depends on cognitive factors. To describe how emotions are identified and classified on the basis of how they feel, we rely on Marcel and Lambie’s distinction between an ‘emotion state’ and an ‘emotion experience’. Both notions indicate kinds of feelings that we consciously experience. However, they describe first-order and second order emotion awareness respectively. The emotion state is the feeling we have of the bodily states and changes that occur when we are experiencing an emotion, while the emotion experience is the fully developed and integrated emotion we both experience and are, with reflection, aware of experiencing. On the basis of this differentiation, we also show that the same characteristics that aid in the identification and classification of bodily experiences (specific qualitative sensations; somatic localization; specific intensity; presence/absence of specific concomitant sensations) can also be used for the identification and classification of emotions – at least basic emotions. In the last two sections of the chapter we present some clinical evidence on the semantic competence of people who suffer from Alexithymia and Autism Spectrum Disorder which supports the conclusions of our preceding analyses. -/- Chapter 6 The ‘Proprioceptive’ Component of Abstract Concepts -/- Abstract. In this chapter, we address the issue of whether the mastery of abstract words requires only inferential knowledge and thus, if the concepts that support the mastery of abstract words include only linguistic information. We start by differentiating the notions of ‘abstract’ and ‘general’ which are often erroneously confused. We then identify a strict definition of abstract, as contrasted with ‘concrete’, that applies to words or concepts whose referent cannot be experienced by the senses. We argue that abstract words/concepts would be better described as theoretical, because they are usually conceived as structured sets of inferential knowledge expressed linguistically; that is, as small theories. Pointing out parallels with Carnap’s analysis of this issue in philosophy of science, we hypothesize that words/concepts denoting non-observable entities are not all ‘equally theoretical’, because their link to sensory experience can be stronger or weaker. We revive the distinction, inspired by Quine, between theoretical and intertheoretical concepts/words. This distinction relies on the fact that the former – unlike the latter – retains a strong, although indirect, connection with perception. In Quine’s discussion, perception is understood uniquely in terms of observability, i.e. of external sensory experience. Here we argue, however, that bodily, ‘proprioceptive’ (i.e. propriosensitive) experience can also serve to referentially ground theoretical (i.e. abstract) concepts/words. We frame this issue using the example of the theoretical concept ‘freedom’ and Lakoff’s hypothesis that this concept is developed on the basis of bodily information. We contrast this with the example of ‘democracy’ which more closely resembles an intertheoretical concept/word. Furthermore, we show that one of the classical views put forward in psycholinguistic research to explain how abstract concepts are mentally represented – i.e. Paivio’s Dual Coding Theory – points in the same direction as our analysis. The same is true of Barsalou’s work suggesting that we use internal information to understand at least some abstract words. To sustain this position, we put forward two lines of evidence: the first comes from psycholinguistic studies while the second examines deficits of semantic competence exhibited by people with Autism Spectrum Disorder. On the basis of our analysis, we put forward a classification that distinguishes between different kinds of concreteness and different degrees of abstraction: concepts/words referring to body experiences and basic emotions are described as analogous to concrete concepts/words because they are grounded in perceptual (i.e. propriosensitive) experience, while abstract concepts/words are considered more or less abstract depending on whether they are intratheoretical (and rely entirely on inferential information) or theoretical (and are partially grounded in perceptual – or more often in propriosensitive perceptual – information). In the last section of the chapter we consider two scales that have been used in psycholinguistic research to measure the degree of concreteness vs. abstractness of words and we show that – used conjointly – they can provide a measure of the internal vs. external grounding of specific words. (shrink)

We highlight connections between accessible categories and abstract elementary classes , and provide a dictionary for translating properties and results between the two contexts. We also illustrate a few applications of purely category-theoretic methods to the study of AECs, with model-theoretically novel results. In particular, the category-theoretic approach yields two surprising consequences: a structure theorem for categorical AECs, and a partial stability spectrum for weakly tame AECs.

As a text in use by mental health practitioners, policy makers, and ordinary individuals, the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) categorizes a variety of mental, psychological, and emotional experiences on a wide spectrum of disorders. Many common experiences are described there as symptoms, chiefly for the purposes of identifying, diagnosing, and treating disorders. “Disorientations” are not (yet) categorized as a stand-alone disorder in the DSM, but involve a cluster of experiences that border on and overlap with (...) experiences already categorized as symptoms of other disorders. Where experiences of disorientation appear in the DSM, they are, for the most part, still understood as.. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Diagnostic WannabesJennifer Radden, PhD (bio)Saunders explores challenges for the clinician faced with self-styled sufferers from attention deficit hyperactivity disorder, post-traumatic stress disorder, bipolar disorder, autism spectrum disorder (ASD), and fibromyalgia. The diagnostic system was not meant to be used as “a scaffold for identity,” she points out. Yet wannabe patients now step into the clinic wielding self-proclaimed diagnoses as social identities. Saunders explains the context where such phenomena (...) arise, and offers guidelines for clinicians addressing this new reality. To do so, she enlists Rashed’s innovative normative approach to the so-called boundary problem of assigning, and providing justification for, the contested line between normal and disordered. The boundary problem itself seems to rise to prominence during our current era of increasingly dimensional thinking, it is worth noting, with psychiatric diagnoses taken to refer to points on a continuum, rather than to discrete categorical disease entities.On the likely sources of these ‘diagnostic’ social identities, as well as reasons why certain diagnoses attach to them more commonly than others, Saunders points to social trends (including what she asserts to be a “post-stigma” cultural environment), the failure of efforts to identify neurobiological markers for psychiatric disorder, the ubiquity of social media, the algorithms themselves, and the hyperconnected existence of contemporary times. Such narratives also offer the comforts of a sense of belonging and explanations for perceived inadequacies, she rightly observes.Despite today’s virtual and other inducements, the problem introduced here is not an entirely new one. The first part of the seventeenth century in Europe saw an apparent “epidemic” of what was known as “melancholy,” a condition associated with the spleen, whose symptoms loosely resembled those of today’s depression and anxiety. Much of this suffering was undeniably real, but much was a fashionable, identity-conferring pose. “Every distemper of the body now is complicated with spleen,” the poet John Donne ironically observes in a letter dated 1622, “and when we were young men we scarce ever heard of the spleen. In our declinations now, every accident is accompanied with heavy clouds of melancholy”1 (Gosse, 2019). By then, the Melancholic Man (or homo melancholicus), with his surfeit of spleen, was an unmistakable character type—or social identity, as we would now say. Recognized and saluted in centuries-long literary and illustrative traditions, the type was an anchoring element of the humoral medicine which, despite the gradual emergence of more empirical science, had endured since Galenic times.Melancholy’s closest descendants, affective depressive and anxiety disorders, are today less evident among the troubling identities Saunders discusses—somewhat preempted, she points out, by more cognitively-based diagnoses such as ASD. [End Page 279] This is itself an ironic reminder of the vagaries of cultural attitudes, cautioning us to remember the broader context where these particular social identities are selected for emulation and adoption.The lure of the melancholy man’s2 social identity is well understood: already normalized, within the humoral system in which excess black bile afflicted roughly one in four people, it had been valorized for centuries—arguably by Aristotelian writing (in the dubious ‘Problems’), during the Renaissance by Ficino, and Shakespeare—even by Freud in his 1916 ‘Mourning and Melancholia.’ Through most of Western history, the positive attributes and benefits of the dark moods of melancholy have needed no further explaining or justifying. They glow with glamorous associations.Applying Rashed’s conditions for appropriately acknowledging and recognizing the fit of a person’s chosen social identity, Saunders‘ guidance for clinicians clarifies boundary matters. And it illustrates how to understand, regulate and communicate the appropriate norms in ways that can dissuade those whose personal growth and mental health are not served by claiming such identities.With at least some of the popular social identities Saunders describes, I think we can helpfully continue the comparison with the homo melancholicus. For the ‘neurodiversity’ rhetoric of our own times contains forces promoting both the normalization and the valorization of syndromes such as ASD. Pointing to analogies with differences of gender, ethnicity and culture, neurodiversity theorizing argues for a respect for, and appreciation of, difference. Mental or cognitive variations are equally natural and valuable, it is... (shrink)

Summary The term empathy has become a linguistic commonplace in everyday communication as well as in interdisciplinary research. The results of the research questions, raised in the last hundred (and more) years, coming from different areas, such as aesthetics, psychology, neurosciences and literary theory, lack in fact a clear concept of empathy. Not surprisingly, a recent paper has identified up to 43 distinct definitions of empathy in academic publications. By reconstructing the main research lines on empathy, our paper highlights the (...) reasons for this conceptual inadequacy and the deficiencies in the theorization of empathy that create misleading interpretations thereof. Along the line connecting Plato’s insights on empathic experiences to the present neuroscientific experiments, a broad spectrum of issues is deployed for which “empathy” functions as an umbrella term covering a net of categorical relationships – projection, transfer, association, expression, animation, anthropomorphization, vivification, fusion, and sympathy – that only partially overlap. Our paper therefore recommends that “empathy” should not be assumed as a self-evident notion but instead preliminarily clarified in its definition every time we decide to have recourse to it. (shrink)

This paper develops an interpretation of the relationship between Kant's various formulations of the categorical imperative in the Groundwork that steers a middle course between the formal and substantive poles of the interpretive spectrum, represented by John Rawls and Barbara Herman, respectively. Accepting and rejecting key aspects of both Rawls's and Herman's interpretations, I argue that the first formulation, understood correctly, does suffice to determine all Kantian moral duties, but only if duties are regarded as situation-specific rather than standing (...) obligations. I also argue, however, that the second and third formulations provide information that is necessary for understanding and applying the first formulation to determine one's duty correctly, and that the formulations are in a sense equivalent even though each plays a distinctive and important role. (shrink)

We give some new examples of possible degree spectra of invariant relations on Δ 0 2 -categorical computable structures, which demonstrate that such spectra can be fairly complicated. On the other hand, we show that there are nontrivial restrictions on the sets of degrees that can be realized as degree spectra of such relations. In particular, we give a sufficient condition for a relation to have infinite degree spectrum that implies that every invariant computable relation on a Δ 0 (...) 2 -categorical computable structure is either intrinsically computable or has infinite degree spectrum. This condition also allows us to use the proof of a result of Moses [23] to establish the same result for computable relations on computable linear orderings. We also place our results in the context of the study of what types of degree-theoretic constructions can be carried out within the degree spectrum of a relation on a computable structure, given some restrictions on the relation or the structure. From this point of view we consider the cases of Δ 0 2 -categorical structures, linear orderings, and 1-decidable structures, in the last case using the proof of a result of Ash and Nerode [3] to extend results of Harizanov [14]. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Close Enemies: The Relationship of Psychiatry and Psychology in the Assessment of Mental DisordersPhilippe Le Moigne, PhDAs Peter Zachar rightly points out in his comment, the assessment of mental disorders underwent new developments with the release of the Diagnostic and Statistical Manual of Mental Disorders-V in 2013 (American Psychiatric Association, 2013). Whereas in 1980, the manual had been thought of in a rigorously categorical way, on the basis of (...) distinct and closed syndromic entities, this new version advocated the development of a radically dimensionalist approach, with the diagnosis aiming this time to restore the whole symptomatological picture of the patient on a spectrum of ratings are supposed to cover the entirety of psychiatric semiology (American Psychiatric Association, 2013).For its part, my article aimed to show how standardized assessment, guided by the return of psychiatry’s authority and the assertion of its legitimacy in the diagnostic field, gave the ascendancy in the 1980s to the classificatory tradition and thus to the categorical model, to the detriment of personality approach and test psychology which offered a competing solution here. This perspective, historically dated, may have led the reader to think that there is an antagonism that cannot be overcome here. Rather, it should be seen as a form of structuring opposition, or even a “complementarity inscribed in rivalry,” between psychiatry and psychology, which is naturally susceptible to change over time.Indeed, the reversal operated by the Diagnostic and Statistical Manual of Mental Disorders-V is not total because it cannot be total. The defense of the dimensionalist approach, dear to the psychological testing tradition, was intended here to allow the identification of co-morbidities, present in most patients but poorly apprehended by the categorical approach, and to open up diagnosis to prevention by screening for minor manifestations of psychopathology when they suggest the [End Page 259] development of a manifest episode of the disease in the more or less long term. The risk here is that we end up with overdiagnosis and thus an over-representation of false positives (Wakefield, 2015). In other words, this type of approach does not escape the obligation to determine threshold scores, likely to indicate the lower limit of the disorder, and thus to resort to a categorical approach. There is a first affinity between the two perspectives which obeys, beyond the divergences in principle, a technical requirement.But the two approaches have even more in common when we look at their epistemological background: they share the idea that the representation and the intervention on mental disorder, to use Ian Hacking’s expression (1983), must be based on the model proposed by the physical and natural sciences. And as Greta Kaluzeviciute aptly points out in her comment, this orientation leads to the idea of measuring mental disorder in particular to conduct elaborate quantification operations to determine, for example, whether two entities are statistically distinct or whether a drug has a significant effect on the evolution of a pathology.This is in fact an old question that can be formulated as follows, to use the expression of the psychometrician Joel Michell (1999): are psychological dimensions metric? In other words, if we want to apply the language of numbers to mental disorders, they must share its properties, two of which seem essential: it must be possible to establish that each mental disorder, in the same way as qualities attributable to length for example, has a zero and can be divided by means of gradients (or degrees of intensity) whose interval is constant (Le Moigne, 2018; Michell, 1999). For lack of space, let us only address the second condition. This one has already been denied by many, starting with Bergson at the end of the nineteenth century (1889). He does not believe in the quantification of psychological expressions, starting with sensations. What is the common point, he wrote, between the feeling of a mild pain, as one feels a stiffness, and the sensation of a needle being hammered into your flesh? For him, one and the other of these intensities are incomparable, so that they do not belong to a similar register of sensations that one could stage from a 0 toward a... (shrink)

The physics of color and the psychology of color naming are not isomorphic. Physically, the spectrum is continuous with regard to wavelength colors change qualitatively from one wavelength region to another. The psychological characterization of hue that characterizes color vision has been revealed in a series of modern psychophysical studies with human adults and infants and with various infrahuman species, including vertebrates and invertebrates. These biopsychological data supplant an older psycholinguistic and anthropological literature that posited that language and culture (...) alone influence perceptual processes; language and culture may modify color naming beyond basic categorizations. (shrink)

Using the description of the Ziegler spectrum we characterise modules with various stability-theoretic properties (ω-stability, superstability, categoricity) over certain classes of finite-dimensional algebras. We also show that, for modules over the algebras we consider, having few types is equivalent to being ω-stable.

Some strongly empiricist views of scientific knowledge advocate a rejection of metaphysics. On such views, scientific knowledge is described strictly in terms of knowledge of the observable world, demarcated by human sensory abilities, and no metaphysical considerations need arise. This paper argues that even these views require some recourse to metaphysics in order to derive knowledge from experience. Central here is the notion of metaphysical inference, which admits of different “magnitudes”, thus generating a spectrum of putative knowledge with more (...) substantially empirical beliefs at one end, and more metaphysically imbued beliefs at the other. Given that metaphysical inference is required even concerning knowledge of the observable, the empiricist hope of avoiding metaphysics altogether is futile: knowledge of the observable simply involves metaphysical inferences that are of smaller magnitudes than others. Metaphysical inferences are required not only to distinguish veridical from non-veridical experience and to determine the quality of empirical information, but also in order to explain how we construct experience (through categorizations and classifications of objects, events, processes, and properties), how we extrapolate from empirical evidence to generalize about observable phenomena, and how we use this evidence to test and confirm hypotheses and theories. (shrink)

The current issue of our journal features a special section on technoscientific developments and animals, an extremely sensitive and highly politicized issue. There is widespread unease and even outrage, at least in many Western societies, over the use and treatment of animals in various sectors, particularly in food production, in technoscience, and in entertainment. The spectrum of opponents to certain uses and treatments of animals extends from those who wish to see better protection of animals to proponents of far-reaching (...) animal rights. On a political level, recent decades have for example seen animal protection included in the German constitution [1] and the use of great apes in animal testing banned in several countries. Such activities are often based on animals being perceived as fellow beings and categorically different from objects. If we look at German history in particular, however, we are reminded that such appreciation of animals often goes hand in hand with a depreciati .. (shrink)

The paper studies Heyting algebras within the framework of computable structure theory. We prove that the class _K_ containing all Heyting algebras with distinguished atoms and coatoms is complete in the sense of the work of Hirschfeldt et al. (Ann Pure Appl Logic 115(1-3):71-113, 2002). This shows that the class _K_ is rich from the computability-theoretic point of view: for example, every possible degree spectrum can be realized by a countable structure from _K_. In addition, there is no simple (...) syntactic characterization of computably categorical members of _K_ (i.e., structures from _K_ possessing a unique computable copy, up to computable isomorphisms). (shrink)