This paper is a general introduction to Positive Logic, where only what we call h-inductive sentences are under consideration, allowing the extension to homomorphisms of model-theoric notions which are classically associated to embeddings; in particular, the existentially closed models, that were primitively defined by Abraham Robinson, become here positively closed models. It accounts for recent results in this domain, and is oriented towards the positivisation of Jonsson theories.

Like the latter, it unites into one and the same function the possibility of giving things a sign, of representing one thing by another, and the possibility of causing a sign to shift in relation to what it designates. The four functions that define the ...

Ni konstruas nun malbonajn korpojn, kun malfinita Morleya ranko, kiuj estas ricevitaj per memsuficanta amalgameco de korpoj kun unara predikato nomanta sumigan au obligan subgrupon, ciam lau la Hrushovskija maniero. Al uzado de ciuj kiuj la anglujon malkonprenas, tiel tradukigas la supera citajo : "Estas prava ke tiu ci kiu kun la sago interrilatigas, la sagecon rikoltas". Gustatempe, la autoro varmege dankas ciujn kiuj la korektan citajon sendis al li, speciale la unuan respondinton : David KUEKER.

We define elementary extension and elementary equivalence in Positive Logic.

The role played by the symmetric structure of a group of finite Morley rank without involutions in the proof by contradiction of Frécon 2018 was put in evidence in Poizat 2018; indeed, this proof consists in the construction of a symmetric space of dimension two (“a plane”), and then in showing that such a plane cannot exist.To a definable symmetric subset of such a group are associated symmetries and transvections, that we undertake here to study in the abstract, without (...) mentioning a group envelopping them. This leads us to consider axiomatically defined structures that we callsymmetrons(preferably todyadic symmetric setsas was done in Lawson & Lim 2004).Glauberman's$Z^*$-Theorem allows to elucidate completely the structure of the finite symmetrons: each of them is isomorphic to the set of symmetries associated to a symmetric subspace of a finite group without involutions, which is far from being uniquely determined. In fact, there exist non-isomorphic finite groups which have the same symmetries, and also finite symmetrons which are not isomorphic to the symmetries of a group.The situation is not so clear in the case of symmetrons of finite Morley rank, or even algebraic, which are the main objects of study of this paper. But in spite of the fact that a symmetron be a structure much weaker that a group, we can extend to symmetrons some well-known results concerning groups of finite Morley rank: chain condition, decomposition into connected components, characterisation of the generic definable subsets, elliptic generation, etc. These properties are new even in the case of a symmetric subspace of a group, and allow to bypass the computations made by Frécon during the construction of his paradoxical plane.Moreover, assuming the Algebricity Conjecture, we generalize Glauberman's Theorem to the finite Morley rank context. (shrink)

Ni konstruas korpojn de Morleja ranko du, kiuj estas ricevitaj per memsuficanta amalgameco de korpoj kun unara predikato, lau la Hrushovkija maniero.

If G is an omega-stable group with a normal definable subgroup H, then the Sylow-2-subgroups of G/H are the images of the Sylow-2-subgroups of G. /// Sei G eine omega-stabile Gruppe und H ein definierbarer Normalteiler von G. Dann sind die Sylow-2-Untergruppen von G/H Bilder der Sylow-2-Untergruppen von G.

Studying consciousness requires contrasting conscious and unconscious perception. While many studies have reported unconscious perceptual effects, recent work has questioned whether such effects are genuinely unconscious, or whether they are due to weak conscious perception. Some philosophers and psychologists have reacted by denying that there is such a thing as unconscious perception, or by holding that unconscious perception has been previously overestimated. This article has two parts. In the first part, I argue that the most significant attack on unconscious perception (...) commits the criterion content fallacy: the fallacy of interpreting evidence that observers were conscious of something as evidence that they were conscious of the task-relevant features of the stimuli. In the second part, I contend that the criterion content fallacy is prevalent in consciousness research. For this reason, I hold that if unconscious perception exists, scientists studying consciousness could routinely underestimate it. I conclude with methodological recommendations for moving the debate forward. (shrink)

We develop a Sylow theory for stable groups satisfying certain additional conditions (2-finiteness, solvability or smallness) and show that their maximal p-subgroups are locally finite and conjugate. Furthermore, we generalize a theorem of Baer-Suzuki on subgroups generated by a conjugacy class of p-elements.

Whether the prefrontal cortex is part of the neural substrates of consciousness is currently debated. Against prefrontal theories of consciousness, many have argued that neural activity in the prefrontal cortex does not correlate with consciousness but with subjective reports. We defend prefrontal theories of consciousness against this argument. We surmise that the requirement for reports is not a satisfying explanation of the difference in neural activity between conscious and unconscious trials, and that prefrontal theories of consciousness come out of this (...) debate unscathed. (shrink)

This paper takes issue with the exemplarist strategy of fostering virtue development with the specific goal of improving its applicability in the context of education. I argue that, for what matters educationally, we have good reasons to endorse a liberal account of moral exemplarity. Specifically, I challenge two key assumptions of Linda Zagzebski’s Exemplarist Moral Theory (2017), namely that moral exemplars are exceptionally virtuous agents and that imitating their behavior is the main strategy for acquiring the virtues. I will introduce (...) and discuss the notions of enkratic exemplars and injustice illuminators and show that we have good reasons to consider them moral exemplars although they fail to satisfy (either of) the key assumptions. (shrink)

Nous définissons une classe de suites de polynômes, calculés par des circuits de complexité polynomiale comprenant des additions, des soustractions, des multiplications et des sommations de Valiant. Nous montrons que cette classe est close pour la prise de la fonction-coefficient, définie au paragraphe 3 de cet article: nous en déduisons l'existence d'un circuit de complexité 72.n2, calculant le coefficient binomial de deux nombres de n chiffres, donnés en base 2. Il est par ailleurs facile de construire un circuit de complexité (...) 17.n + 2 calculant la factorielle d'un nombre de n chiffres. La présence de 2.n sommations d'effet exponentiel dans chacun de ces circuits en affecte gravement l'intérêt pratique. Il est peu probable, ou du moins peu souhaitable, qu'on puisse éliminer ces sommations sans explosion, car cela provoquerait la catastrophe cryptographique que redoutent tous les banquiers: néanmoins, nous ne savons pas séparer la classe définie ici de celle des suites de polynômes calculables en un nombre polynomial d'opérations arithmétiques. Cela n'a rien de surprenant, vu la très grande affinité qu'elle a avec la classe PSPACE: nous montrons en effet que cette classe est identique à la classe VPSPACE, définie antérieurement par Koiran et Perifel, qui apparaît ici sous une forme bien plus maniable que l'originale. (shrink)

We comment on an early and inspiring remark of an Omskian mathematician concerning the Cherlin—Zilber Conjecture, meeting in passing some well-known properties of algebraic groups whose generalization to arbitrary groups of finite Morley rank seems to be very uncertain. This paper assumes a familiarity with the model theoretic tools involved in the study of the groups of finite Morley rank.

To study (un)conscious perception and test hypotheses about consciousness, researchers need procedures for determining whether subjects consciously perceive stimuli or not. This article is an introduction to a family of procedures called ‘confidence-based procedures’, which consist in interpreting metacognitive indicators as indicators of consciousness. I assess the validity and accuracy of these procedures, and answer a series of common objections to their use in consciousness research. I conclude that confidence-based procedures are valid for assessing consciousness, and, in most cases, accurate (...) enough for our practical and scientific purposes. (shrink)

According to a recent account of epistemic authority proposed by Linda Zagzebski (2012), it is rational for laypersons to believe on authority when they conscientiously judge that the authority is more likely to form true beliefs and avoid false ones than they are in some domain. Christoph Jäger (2016) has recently raised several objections to her view. By contrast, I argue that both theories fail to adequately capture what epistemic authority is, and I offer an alternative account grounded in the (...) abilities that different kinds of authorities are required to possess. (shrink)

Consciousness scientists have not reached consensus on two of the most central questions in their field: first, on whether consciousness overflows reportability; second, on the physical basis of consciousness. I review the scientific literature of the 19th century to provide evidence that disagreement on these questions has been a feature of the scientific study of consciousness for a long time. Based on this historical review, I hypothesize that a unifying explanation of disagreement on these questions, up to this day, is (...) that scientific theories of consciousness are underdetermined by the evidence, namely, that they can be preserved “come what may” in front of (seemingly) disconfirming evidence. Consciousness scientists may have to find a way of solving the persistent underdetermination of theories of consciousness to make further progress. (shrink)

This paper confronts Zagzebski’s exemplarism with the intertwined debates over the conditions of exemplarity and the unity-disunity of the virtues, to show the advantages of a pluralistic exemplar-based approach to moral education (PEBAME). PEBAME is based on a prima facie disunitarist perspective in moral theory, which amounts to admitting both exemplarity in all respects and single-virtue exemplarity. First, we account for the advantages of PEBAME, and we show how two figures in recent Italian history (Giorgio Perlasca and Gino Bartali) satisfy (...) Blum’s definitions of ‘moral hero’ and ‘moral saint’ (1988). Then, we offer a comparative analysis of the effectiveness of heroes and saints with respect to character education, according to four criteria derived from PEBAME: admirability, virtuousness, transparency, and imitability. Finally, we conclude that both unitarist and disunitarist exemplars are fundamental to character education; this is because of the hero's superiority to the saint with respect to imitability, a fundamental feature of the exemplar for character education. (shrink)

Phillips argues that blindsight is due to response criterion artefacts under degraded conscious vision. His view provides alternative explanations for some studies, but may not work well when one considers several key findings in conjunction. Empirically, not all criterion effects are decidedly non-perceptual. Awareness is not completely abolished for some stimuli, in some patients. But in other cases, it was clearly impaired relative to the corresponding visual sensitivity. This relative dissociation is what makes blindsight so important and interesting.

This chapter introduces a novel account of fake news and explains how it differs from other definitions on the market. The account locates the fakeness of an alleged news report in two main aspects related to its production, namely that its creators do not think to have sufficient evidence in favor of what they divulge and they fail to display the appropriate attitude towards the truth of the information they share. A key feature of our analysis is that it does (...) not require that fake news must be circulated with the intention to deceive one’s audience. In this way, our account overcomes a potential limitation of the current philosophical discussion about fake news, which appears to individuate the main problem with this phenomenon in the fact that fake news consumers are misled and misinformed. In contrast, the proposed analysis shows that an additional (and perhaps equally fundamental) problem uncovered by the spread of fake news is a widespread pathological relationship with information, one on which we consume information not to satisfy our interest in the truth but to strengthen our social identities and quench our hunger for social recognition. (shrink)

Is perceptual processing in dedicated sensory areas sufficient for conscious perception? Localists say ‘Yes—given some background conditions.’ Prefrontalists say ‘No: conscious perceptual experience requires the involvement of prefrontal structures.’ I review the evidence for prefrontalism. I start by presenting correlational evidence. In doing so, I answer the ‘report argument’, according to which the apparent involvement of the prefrontal cortex in consciousness stems from the requirement for reports. I then review causal evidence for prefrontalism and answer the ‘lesion argument’, which purports (...) to show that prefrontalism is wrong because lesions to the prefrontal cortex do not abolish consciousness. I conclude that multiple sources of evidence converge toward the view that the prefrontal cortex plays a significant role in consciousness. (shrink)

To study consciousness, scientists need to determine when participants are conscious and when they are not. They do so with consciousness detection procedures. A recurring skeptical argument against those procedures is that they cannot be calibrated: there is no way to make sure that detection outcomes are accurate. In this article, I address two main skeptical arguments purporting to show that consciousness scientists cannot calibrate detection procedures. I conclude that there is nothing wrong with calibration in consciousness science.

Local theories of consciousness state that one is conscious of a feature if it is adequately represented and processed in sensory brain areas, given some background conditions. We challenge the core prediction of local theories based on long-lasting postdictive effects demonstrating that features can be represented for hundreds of milliseconds in perceptual areas without being consciously perceived. Unlike previous empirical data aimed against local theories, localists cannot explain these effects away by conjecturing that subjects are phenomenally conscious of features that (...) they cannot report. We also discuss alternative explanations that localists could offer. (shrink)