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)

When “divided attention” methods were discovered in the 1950s their implications for conscious experience were not widely appreciated. Yet when people process competing streams of sensory input they show both selective processesandclear contrasts between conscious and unconscious events. This paper suggests that the term “attention” may be best applied to theselection and maintenanceof conscious contents and distinguished from consciousness itself. This is consistent with common usage. The operational criteria for selective attention, defined in this way, are entirely different from those (...) used to assess consciousness. To illustrate the scientific usefulness of the distinction it is applied to Posner's brain model of visual attention. It seems that features that are often attributed to attention—like limited capacity—may more accurately be viewed as properties of consciousness. (shrink)

Cet article étudie les principales classifications grecques anciennes des sciences mathématiques. Je souligne le rôle joué par Platon dans cette topique.

Anderson and Csima :245–264, 2014) defined a jump operator, the bounded jump, with respect to bounded Turing reducibility. They showed that the bounded jump is closely related to the Ershov hierarchy and that it satisfies an analogue of Shoenfield jump inversion. We show that there are high bounded low sets and low bounded high sets. Thus, the information coded in the bounded jump is quite different from that of the standard jump. We also consider whether the analogue of the Jump (...) Theorem holds for the bounded jump: do we have A≤bTB\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$A \le _{bT}B$$\end{document} if and only if Ab≤1Bb\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$A^b \le _1 B^b$$\end{document}? We show the forward direction holds but not the reverse. (shrink)

Whatever our profession we are all engulfed in daily life and in the obscurity and density of the mental world. Who is this “I” that finds expression in such a wide variety of societies, in the convictions of the group and temperament of the individual self, in all that I perceive imperfectly and that makes me me? What does this sometimes slippery, sometimes thorny “I” say about the various attitudes towards knowing: the things I desperately want to know, things I (...) believe myself capable of dispensing with, those I fear knowing? (shrink)

The self as the identification of the self with itself is a product of the dynamic transformation of European culture beginning in the Renaissance. The self, or absolute ego, was an outgrowth of the consciously rationalist spirit. However, modernity's Faustian drive was conscious paradoxically without being self conscious of itself or its cultural creations. Modernism deconstructed the values and assumptions of modernity. A casualty was the problematization of the self that had been banished and/or erased by formalism, structuralism and deconstruction. (...) The modernist self erases the absolute ego reconstructing it with a rich, complex, narrative idea of a self‐conscious relational self encompassing memory, repression, autobiography and history. This paper explores the modernist conception of self in Marcel Proust's In Search of Lost Time. Proust demolishes the absolute ego in favor of the paradoxical self which knows itself only in relation to otherness actualized in persons and culture in the sacred time of existence. (shrink)

Current thinking and research on consciousness and the brain.

Let $D_{tt} $ denote the set of truth-table degrees. A bijection π: $D_{tt} \to \,D_{tt} $ is an automorphism if for all truth-table degrees x and y we have $ \leqslant _{tt} \,y\, \Leftrightarrow \,\pi (x)\, \leqslant _{tt} \,\pi (y)$ . We say an automorphism π is fixed on a cone if there is a degree b such that for all $x \geqslant _{tt} b$ we have π(x) = x. We first prove that for every 2-generic real X we have (...) X' $X' \le _{tt} \,X\, \oplus \,0'$ . We next prove that for every real $X \ge _{tt} \,0'$ there is a real Y such that $Y \oplus 0{\text{'}}\, \equiv _{tt} \,Y{\text{'}} \equiv _{tt} \,X$ . Finally, we use this to demonstrate that every automorphism of the truth-table degrees is fixed on a cone. (shrink)

The world of our experience consists at all times of two parts, an objective and a subjective part . . . The objective part is the sum total of whatsoever at any given time we may be thinking of, the subjective part is the inner 'state' in which the thinking comes to pass.

Citizenship as a compulsory subject was added to the National Curriculum in England in 2002 following the 1998 report, 'Education for Citizenship and the Teaching of Democracy in Schools'. It was little noticed at the time that the report stressed active citizenship much more strongly than democracy. The underlying presupposition was what historians call 'civic republicanism' the tradition from the Greeks and the Romans of good government as political government, that is, citizens reaching acceptable compromises of group interests and values (...) by public debate. This is contrasted to modern liberalism. To stress 'democracy' unduly in citizenship education can lead to definitional dogmatics about multiple meanings of the term, even to disillusionment. Democracy is a necessary element in good government but not a sufficient one, unless subjective opinion is enshrined over knowledge through education. The practices of free politics are both historically and logically prior to democracy. (shrink)

Cette étude envisage les notions de sujet, d’individu et de personne dans une perspective d’anthropologie historique. La période considérée va de la disparition de l’Empire romain d’Occident à la mutation féodale, et son analyse est centrée sur la convergence de la culture savante – c’est-à-dire chrétienne – avec ce que nous pouvons savoir de la culture populaire à propos des trois notions précitées. Inaugurée par saint Augustin dans ses Confessions, l’émergence de la notion de personne coïncide avec l’oblitération du sujet (...) dans le De Trinitate de l’évêque d’Hippone. Cette conception rejoint celle du corps grotesque qui traverse la culture populaire de cette époque. Quant à l’individu, il n’apparaît durant toute la période considérée que sous la forme de l’individu particulier dans le cadre d’une individualité de types, et non sous celle de l’individu singulier propre à notre modernité. (shrink)

A real X is defined to be relatively c.e. if there is a real Y such that X is c.e.(Y) and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${X \not\leq_T Y}$$\end{document}. A real X is relatively simple and above if there is a real Y (...) nonempty \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\Pi^0_1}$$\end{document} class contains a member which is not relatively c.e. and that every 1-generic real is relatively simple and above. (shrink)

This study is based on the self-reporting by circus artists’ concerning their injuries. We refer to the theoretical framework of emersiology and argue that circus artists may be able to soothe their distress and pain by learning through their body. We will draw further on the comparison between our therapeutic approach and the techniques of self-care introduced by Michel Foucault in his History of Sexuality.

Voir son cerveau en première personne s’activer à l’occasion de la réalisation d’une tâche semble établir plus qu’une corrélation en décrivant ce qui serait un lien de causalité entre le corps et son cerveau. Le corps est une surface et un résultat dont la conscience ne perçoit le processus vivant qu’en retard sur la vitalité et la mobilité du cerveau. Nous sommes en retard sur notre cerveau mais notre conscience du présent ne peut avoir accès à la temporalité de sa (...) condition. La transparence du cerveau in vivo implique des dispositifs neuro-expérientiels. (shrink)