It is well-known that natural axiomatic theories are well-ordered by consistency strength. However, it is possible to construct descending chains of artificial theories with respect to consistency strength. We provide an explanation of this well-orderedness phenomenon by studying a coarsening of the consistency strength order, namely, the$\Pi ^1_1$reflection strength order. We prove that there are no descending sequences of$\Pi ^1_1$sound extensions of$\mathsf {ACA}_0$in this ordering. Accordingly, we can attach a rank in this order, which we call reflection rank, to any$\Pi (...) ^1_1$sound extension of$\mathsf {ACA}_0$. We prove that for any$\Pi ^1_1$sound theoryTextending$\mathsf {ACA}_0^+$, the reflection rank ofTequals the$\Pi ^1_1$proof-theoretic ordinal ofT. We also prove that the$\Pi ^1_1$proof-theoretic ordinal of$\alpha $iterated$\Pi ^1_1$reflection is$\varepsilon _\alpha $. Finally, we use our results to provide straightforward well-foundedness proofs of ordinal notation systems based on reflection principles. (shrink)

RésuméQuels sont les objets de la perception? Deux réponses célèbres à cette question soutiennent que ce sont soit les images des objets extramentaux, c'est-à-dire la façon dont ils nous apparaissent, soit les objets eux-mêmes. Dans cet article, je présente une analyse de cette question par Abū l-Barakāt al-Baġdādī, un savant post-avicennien dont l'impact sur l'histoire de la philosophie islamique a été largement négligé. Abū l-Barakāt s'est opposé au dualisme épistémologique traditionnel aristotélicien-avicennien, qui établit une distinction entre la perception sensorielle des (...) particuliers matériels et la conception des universaux immatériels, notamment en ce qui concerne le percevant et/ou la structure de la perception. Selon la théorie d'Abū l-Barakāt, tous les actes épistémiques ont la structure unifiée d'une relation directe entre un même percevant et les objets eux-mêmes – matériels et immatériels. Sa thèse principale consiste à dire qu'avoir des organes corporels n'est pas nécessaire pour la perception sensorielle. Dans la dernière section de cet article, je montre que la critique d'Abū l-Barakāt de la tradition aristotélicienne-avicennienne fut considérée comme une innovation révolutionnaire en épistémologie. Cela peut avoir déterminé les théories épistémologiques de deux des philosophes arabes postavicenniens les plus importants : Faḫr al-Dīn al-Rāzī et Šihāb al-Dīn al-Suhrawardī. (shrink)

In _Essentialität und Notwendigkeit: Avicenna und die Aristotelische Tradition_ stellt Fedor Benevich Avicennas Theorie der Essenz und der wissenschaftlichen Bestimmung essentieller und notwendiger Attribute in einem historischen Kontext der aristotelischen Tradition. In _Essentialität und Notwendigkeit: Avicenna und die Aristotelische Tradition_ Fedor Benevich presents Avicenna’s theory of essence and the scientific determination of essential and necessary attributes in its historical context of the Aristotelian tradition.

In this paper, we study finitely axiomatizable conservative extensions of a theoryUin the case whereUis recursively enumerable and not finitely axiomatizable. Stanisław Krajewski posed the question whether there are minimal conservative extensions of this sort. We answer this question negatively.Consider a finite expansion of the signature ofUthat contains at least one predicate symbol of arity ≥ 2. We show that, for any finite extensionαofUin the expanded language that is conservative overU, there is a conservative extensionβofUin the expanded language, such that$\alpha (...) \vdash \beta$and$\beta \not \vdash \alpha$. The result is preserved when we consider eitherextensionsormodel-conservative extensionsofUinstead ofconservative extensions. Moreover, the result is preserved when we replace$\dashv$as ordering on the finitely axiomatized extensions in the expanded language by a relevant kind of interpretability, to witinterpretability that identically translates the symbols of the U-language.We show that the result fails when we consider an expansion with only unary predicate symbols for conservative extensions ofUordered by interpretability that preserves the symbols ofU. (shrink)

Essentialism can be defined as a metaphysical theory according to which things have essential and accidental properties. In this paper, I will address Avicennian essentialism, that is, essentialism...

ABSTRACTScholarship on medieval philosophy has rightfully acknowledged the historical and systematical merit of Avicenna’s thought in all divisions of philosophy. Avicenna however did not...

One of the most widespread claims combining epistemology and metaphysics in post-Avicennian Islamic philosophy was that every object of thought is real. In Muʿtazilite reading, it was endorsed due to a theory of knowledge which states that knowledge is a connection or relation between the knower and the object known. Avicennists accepted it due to the rule that in a proposition “s is p” if p is something positive s has to be positive and real too. Hence, insofar as one (...) can conceptually distinguish between two non-existent items, they have to be real. In this article, the author presents significant consequences of this theory: the acceptance and denial of non-existent yet real extramental objects; the concept of mental existence as an alternative solution; the conceivability of paraconsistent ideas and their reality or reducibility to some real objects. (shrink)

We consider the well-known provability logic GLP. We prove that the GLP-provability problem for polymodal formulas without variables is PSPACE-complete. For a number n, let L0n\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${L^{n}_0}$$\end{document} denote the class of all polymodal variable-free formulas without modalities ⟨n⟩,⟨n+1⟩,...\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\langle n \rangle,\langle n+1\rangle,...}$$\end{document}. We show that, for every number n, the GLP-provability problem for formulas from L0n\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${L^{n}_0}$$\end{document} (...) is in PTIME. (shrink)

A central question in the history of metaphysics concerns the ontological status of such notions as 'redness,' 'humanity,' or 'animality,' which one calls 'universals.' Since one uses these notions to describe objects in the real world, it may seem intuitive that they exist in extramental reality: one says that universals are 'real'. Famously, though, several problems arise from this view. A central problem known both to medieval and contemporary scholars goes as follows: I look at a red rose and recognize (...) that there is 'redness' in it. Then, I look at a red apple and recognize that there is 'redness' in it, too. Does this mean that one and the same 'redness' appears in both the rose and the... (shrink)

The concept of retroactive apparent occurrence, the main ingredient of Wheeler's delayed-choice thought experiments, is systematically incorporated into the quantum theory of measurement (in the framework of the recent review of Busch, Lahti, and Mittelstaedt). Besides, the (general) notion of individual-system measurement is introduced, and, due to it, premeasurement is defined by a truly minimal condition. Finally, retroactive apparent occurrence is made use of to derive apparent objectification in measurement. The derivation is discussed in the framework of the quantum mechanical (...) approach to the objectification problem. (shrink)

Avicenna's analysis of the definition of substance and accident repeatedly emphasizes two points: one and the same essence cannot be substance in one instance and accident in another; whetherxis extrinsic or intrinsic for an underlying subject,ydoes not tell us anything as to whetherxis substance or not. Both points are development in an argument against certain unnamed people who claimed the opposite. In this article I will show that Avicenna's opponents are to be identified with the mainstream Baghdad Peripatetic School which (...) based itself on the Late Antique rule that “parts of substances are substances”. As for Avicenna's own position, it was developed on the basis of the heterodox position of Yaḥyā b. ʿAdī, who anticipated Avicenna's first point. This is a further piece of evidence for something that has only recently begun to be appreciated: the influence of Ibn ʿAdī on Avicenna.RésuméL’analyse d’Avicenne portant sur les définitions de la substance et de l’accident met en exergue les deux propositions suivantes: 1) la même essence ne peut être à la fois une substance dans un cas et un accident dans un autre; 2) le fait quexsoit extrinsèque ou intrinsèque à unysous-jacent ne nous permet pas de conclure quexest une substance. Ces deux propositions sont articulées dans un débat avec d’autres personnes ayant un point de vue opposé dont on ne connaît pas l’identité. Dans cet article, nous verrons que ces adversaires font partie de l’école péripatétique de Bagdad, qui elle-même s’appuie sur une proposition datant de l’Antiquité tardive et selon laquelle les parties de substances sont elles-mêmes des substances. La position d’Avicenne fut développée à partir de celle de Yaḥyā b. ʿAdī. Cet article apporte ainsi un argument nouveau qui met en évidence l’influence, remarquée seulement depuis peu, d’Ibn ʿAdī sur Avicenne. (shrink)

The theory of essential definitions is a fundamental anti‐sceptic element of the Aristotelian‐Avicennian epistemology. In this theory, when we distinguish the genus and the specific differentia of a given essence we thereby acquire a scientific understanding of it. The aim of this article is to analyse systematically the sceptical reasons, arguments and conclusions against real definitions of three major authorities of twelfth‐century Arabic philosophy: Faḫr al‐Dīn al‐Rāzī, Šihāb al‐Dīn al‐Suhrawardī and Abū l‐Barakāt al‐Baġdādī. I focus on showing how their refutation (...) of our capacity to provide essential definitions of things is rooted in their semantic theory: we only know things under certain descriptions which are identical to the meanings of the words that we use to refer to them, yet these descriptions do not capture the essences of things in themselves. The best result one can achieve with Aristotelian‐Avicennian scientific definitions is a “nominal definition”. With this, Rāzī, Suhrawardī and Abū l‐Barakāt will put some serious epistemic limitations on our capacity to attain scientific knowledge of things, at least as Aristotle and Avicenna would have it. (shrink)

This is a translation of an article which appeared in 1928 in the journal Red Virgin Soil (Krasnaya nov) founded by Aleksandr Voronsky. Its author, the Russian Marxist Fedor Kapelusz, makes use of the now largely-ignored book of Algie Simons, Social Forces in American History (1911). In comparing America’s past to its present, Kapelusz offers a sharp political assessment and at the same time a contribution to the materialist conception of American history.

Increasingly, the private sector is playing a greater role in supporting peace building efforts in conflict and post-conflict areas by providing critical expertise, know-how, and capital. However, reports of the corrupt practices of both governments and businesses have plagued international peace building efforts, deepening the distrust of stricken communities. Businesses are perceived as being selfish and indifferent to the impact their operations may have on the social and political development of local communities. Additionally, the corruption of local governments has been (...) cited as interfering with the creation of stability in conflict areas. Within this framework, multinational Public-Private Partnerships can exert two forms of influence: they can either exacerbate these problems, or they can become part of the solution. Without a relationship of trust among local businesses, government, and the private sector, peace building efforts will at best be mixed, and could possibly perpetuate violence in fragile states. Public and private interests are better served when Public-Private Partnerships are based upon collaboration and assist in establishing principles of good governance in conflict areas. This in turn can help build trust and regain the credibility of both sectors among local communities, which are essential in making Public— Private Partnerships more effective. (shrink)

RésuméDans cet article, je soutiendrai que divers philosophes du kalām s'accordent à dire que la perception sensorielle dépasse les processus physiques dans les organes sensoriels. Il peut se passer quelque chose dans nos yeux lorsque nous voyons une pomme rouge, mais voir une pomme rouge ne s'y réduit pas. Nous verrons que certains philosophes du kalām soutiennent que la perception sensorielle est semblable à une prise de conscience ou à une conscience de l'objet de la perception, et qu'elle est, par (...) conséquent, distincte du processus physique dans les organes sensoriels. Un groupe ira jusqu’à accepter que la perception sensorielle ne dépend même d'aucun processus physique dans le corps. Un autre groupe acceptera que la perception sensorielle présuppose diverses conditions physiques, mais il considérera néanmoins la perception sensorielle comme quelque chose de distinct de l'occurrence de ces conditions. Je suggère que ces théories non réductionnistes de la perception sensorielle sont la raison pour laquelle les philosophes arabo-islamiques, à partir du XIe siècle, rejettent systématiquement la théorie aristotélico-avicennienne de la perception sensorielle. (shrink)

The article attempts to explain the difficulty of systematization of philosophical categories. Philosophical categories are defined as common forms of cognitive and world view attitude of the man to the nature, society and his own existence. The article also analyses basic approaches to the process of creating the system of philosophical categories in the history of philosophical thought. The review of the major historical phases of philosophical interpretation of categories allows to state the existence of the problematic issue connected with (...) forming the system of categories. A lot of attempts have been undertaken on this subject. All of them were found controversial. It can be explained by the fact that all the attempts to systematize categories contradict the following principles - if categories are universal reflection forms of objective characteristics of existence, then their hierarchy must be the reflection of these characteristics’ hierarchy. But it is impossible to imagine that the "hierarchy" principle operates in the system of being, because the objective world is organized rather on the principle of "equality" than "subordination". The article addresses functional and developmental characteristics of philosophical categories. The article gives the author`s understanding of the concept of "philosophical categories". (shrink)

Increasingly, the private sector is playing a greater role in supporting peace building efforts in conflict and post-conflict areas by providing critical expertise, know-how, and capital. However, reports of the corrupt practices of both governments and businesses have plagued international peace building efforts, deepening the distrust of stricken communities. Businesses are perceived as being selfish and indifferent to the impact their operations may have on the social and political development of local communities. Additionally, the corruption of local governments has been (...) cited as interfering with the creation of stability in conflict areas. Within this framework, multinational Public-Private Partnerships can exert two forms of influence: they can either exacerbate these problems, or they can become part of the solution. Without a relationship of trust among local businesses, government, and the private sector, peace building efforts will at best be mixed, and could possibly perpetuate violence in fragile states. Public and private interests are better served when Public-Private Partnerships are based upon collaboration and assist in establishing principles of good governance in conflict areas. This in turn can help build trust and regain the credibility of both sectors among local communities, which are essential in making Public— Private Partnerships more effective. (shrink)

In this article the author holds that progress in philosophy is a vague concept. Its criteria are not universally acknowledged. All that is clear is that philosophy does not develop in a linear way. Philosophy is polydiscoursive. As for the past fifty years, the author believes three important things happened in philosophy. (1) It has been shown that consciousness exists not within one individual but spreads within a community of people; (2) philosophy has discovered autism, a result that helps us (...) to understand a human being as neither a biological nor a social individual but a third thing—a dreaming being who is not only asocial but also tongueless, where speech and consciousness are separated; and (3) contemporary philosophy has learned to distinguish between sign and symbol. And it has been realized that the human mind is neither an instinct nor a computer but an objectified suffering, a transformed emotion. (shrink)

I would like to begin with the role of philosophy in solving ecological problems, emphasizing two aspects of its role: the struggle against hostile ideology and the organizing and guiding of activity in the sphere of the development of science and the shaping of its problems. This role of Marxist-Leninist philosophy clearly appears in the complex interdisciplinary problem of the interaction between nature and society.

O século XX trouxe uma ciência impossível: a ciência da mente. Esta ciência ignora os problemas semiológico, nosológico e sociocultural a ela inerentes e que a inviabilizam. Como resultado, observamos a criação de uma pandemia global de transtornos mentais, majoritariamente administrados através de psicofármacos. Em contraponto, o pensamento filosófico desafia esta logica desde Canguilhem, passando por Michel Foucault, Deleuze & Guattari, dentre tantos outros. E da Éticaespinosana dos afetos e afecções, nasceu a Heterogênese Urbana (HU), que tem como objeto original (...) a revitalização criativa das potências humanas através do contato entre subjetividades diversas. Etimologicamente, “criação a partir e com a diversidade”. Com a circulação dos afetos, dos desejos, das ideias nos espaços públicos, a HU promove, fenomenologicamente, a expressão daquilo que, antes permanecia invisível e indizível face o silêncio da vida da cidade. Os campos de afetações intersubjetivo e intercorpóreo entre vidas tão distintas desloca e descola o olhar fundado na psicopatologia clássica para atravessar a vida da cidade pelas potências que cada indivíduo é capaz nas experiências coletivas.A HU denuncia a multicomplexidade do conceito “produção de saúde”, que apenas inicia-se nas práticas biomédicas, compreendendo todos os saberes para a construção do cidadão autônomo e afetivo. (shrink)

Philosophizing at Russian theological academies is a complex and ramified cultural-historical formation that developed within the Orthodox confession and goes back to the earliest stages of Russian religious-philosophical culture. The formal content of this concept consists of the philosophy courses taught at the Russian theological academies, established on the basis of the 1809 Charter of Theological Academies, and of the philosophical works of the professors and lecturers at these academies, mostly the philosophical articles in the theological journals published by the (...) academies. (shrink)

In recent years attention to the philosophical and literary production of P. A. Florenskii has become commonplace. The thinker's intellectual legacy is very great. In September 1919, Florenskii wrote a prospectus for a collection of his own writings, which would have amounted to nineteen volumes. The collection was not published, for a number of reasons; nonetheless, many of the philosopher's works did come out during his lifetime. Florenskii's writing, published in small editions and scattered among various journals, are still quite (...) inaccessible to readers. (shrink)

Russian Romanticism, which first acquired recognizable contours in the 1820s, was a substantively significant phenomenon in Russian culture. Russian Romanticism assumed the unique forms of a sociophilosophical and literaryesthetic current that did not take shape within the confines of a purely literary movement. Romanticism was an important element in the culturalhistorical development of mankind; it was a special type of philosophicalhistorical interpretation of the world and a special type of esthetic awareness and literary-artistic conduct.

В сборник включены ранее не публиковавшиеся религиозно-философские произведения Ф. Н. Глинки.

By a well-known result of Kotlarski et al., first-order Peano arithmetic \ can be conservatively extended to the theory \ of a truth predicate satisfying compositional axioms, i.e., axioms stating that the truth predicate is correct on atomic formulae and commutes with all the propositional connectives and quantifiers. This result motivates the general question of determining natural axioms concerning the truth predicate that can be added to \ while maintaining conservativity over \. Our main result shows that conservativity fails even (...) for the extension of \ obtained by the seemingly weak axiom of disjunctive correctness \ that asserts that the truth predicate commutes with disjunctions of arbitrary finite size. In particular, \ implies \\). Our main result states that the theory \ coincides with the theory \ obtained by adding \-induction in the language with the truth predicate. This result strengthens earlier work by Kotlarski and Cieśliński. For our proof we develop a new general form of Visser’s theorem on non-existence of infinite descending chains of truth definitions and prove it by reduction to Gödel’s second incompleteness theorem, rather than by using the Visser–Yablo paradox, as in Visser’s original proof. (shrink)

No argument from the Arabic philosophical tradition has received more scholarly attention than Avicenna's ‘flying man’ thought experiment, in which a human is created out of thin air and is able to grasp his existence without grasping that he has a body. This paper offers a new interpretation of the version of this thought experiment found at the end of the first chapter of Avicenna's treatment of soul in theHealing. We argue that it needs to be understood in light of (...) an epistemological theory set out elsewhere by Avicenna, which allows that all the constitutive properties of an essence will be clear to someone who understands and considers that essence. On our reading, this theory is put to work in the ‘flying man’: because the flying man would grasp that his own essence has existence without grasping that he has a body, connection to body cannot be constitutive of the essence. (shrink)

We fix a gap in a proof in our paper Reducing ω-model reflection to iterated syntactic reflection.

Journal of Mathematical Logic, Volume 23, Issue 02, August 2023. In mathematical logic there are two seemingly distinct kinds of principles called “reflection principles.” Semantic reflection principles assert that if a formula holds in the whole universe, then it holds in a set-sized model. Syntactic reflection principles assert that every provable sentence from some complexity class is true. In this paper, we study connections between these two kinds of reflection principles in the setting of second-order arithmetic. We prove that, for (...) a large swathe of theories, [math]-model reflection is equivalent to the claim that arbitrary iterations of uniform [math] reflection along countable well-orderings are [math]-sound. This result yields uniform ordinal analyzes of theories with strength between [math] and [math]. The main technical novelty of our analysis is the introduction of the notion of the proof-theoretic dilator of a theory [math], which is the operator on countable ordinals that maps the order-type of [math] to the proof-theoretic ordinal of [math]. We obtain precise results about the growth of proof-theoretic dilators as a function of provable [math]-model reflection. This approach enables us to simultaneously obtain not only [math], [math] and [math] ordinals but also reverse-mathematical theorems for well-ordering principles. (shrink)

No crucial experiment demonstrates that four hue categories are needed to describe color appearance. Instead, converging lines of evidence suggest that the terms red, yellow, green, and blue are sufficient and precise enough for deriving color discrimination functions and for a useful model constraining relations between color appearance and neuronal responses. Such a model need not be based on linguistic universals. Until something better is available, this holds.

The paper is devoted to Nikolay Lossky who was one of the leading Russian philosophers of the first half of the twentieth century. We demonstrate the interrelationship between three aspects of Lossky’s philosophy: realism in the theory of knowledge, hierarchical personalism, and supra-naturalistic concept of evolution. We pay attention to the contemporary relevance of Lossky, and we discuss and critique his ideas in light of those of other philosophers. Lossky acknowledges that the subject interacts with being itself and that knowledge (...) is not a shadow or copy of being. His ontology is based on intuitivism and epistemological optimism. Its main categories are God, as the super-systematic principle, and monads. In Lossky’s metaphysics, the idea of abstract ideal principles of being is quite harmoniously combined with personalism. Lossky’s ontology has strong ethical underpinnings. He considers that values are rooted in being and that the evolution of the world is directed by God towards the good. Lossky elaborates a supra-naturalistic concept of evolution. He extrapolates principles of teleological determination, which are fundamental to human existence, on the underlying levels of the world as a whole. Many trends of modern thought are in tune with Lossky’s philosophy, including a return to metaphysics, panpsychism, Platonism, and the desire to unite the religious worldview with new scientific discoveries. (shrink)

When young children learn to use language, they start to use their hands in co‐verbal gesturing. There are, however, considerable differences between children, and it is not completely understood what these individual differences are due to. We studied how children at 4 years of age employ speech and iconic gestures to convey meaning in different kinds of spatial event descriptions, and how this relates to their cognitive abilities. Focusing on spontaneous illustrations of actions, we applied a semantic feature (SF) analysis (...) to characterize combinations of speech and gesture meaning and related them to the child's visual‐spatial abilities or abstract/concrete reasoning abilities (measured using the standardized SON‐R test). Results show that children with higher cognitive abilities convey significantly more meaning via gesture and less solely via speech. These findings suggest that young children's use of cospeech representational gesturing is positively related to their mental representation and reasoning abilities. (shrink)

The theory of essential definitions is a fundamental anti‐sceptic element of the Aristotelian‐Avicennian epistemology. In this theory, when we distinguish the genus and the specific differentia of a given essence we thereby acquire a scientific understanding of it. The aim of this article is to analyse systematically the sceptical reasons, arguments and conclusions against real definitions of three major authorities of twelfth‐century Arabic philosophy: Faḫr al‐Dīn al‐Rāzī, Šihāb al‐Dīn al‐Suhrawardī and Abū l‐Barakāt al‐Baġdādī. I focus on showing how their refutation (...) of our capacity to provide essential definitions of things is rooted in their semantic theory: we only know things under certain descriptions which are identical to the meanings of the words that we use to refer to them, yet these descriptions do not capture the essences of things in themselves. The best result one can achieve with Aristotelian‐Avicennian scientific definitions is a “nominal definition”. With this, Rāzī, Suhrawardī and Abū l‐Barakāt will put some serious epistemic limitations on our capacity to attain scientific knowledge of things, at least as Aristotle and Avicenna would have it. (shrink)

This book constitutes the refereed proceedings of the 13th International Scandinavian Symposium and Workshops on Algorithm Theory, SWAT 2012, held in Helsinki, Finland, in July 2012, co-located with the 23rd Annual Symposium on Combinatorial Pattern Matching, CPM 2012. The 34 papers were carefully reviewed and selected from a total of 127 submissions. The papers present original research and cover a wide range of topics in the field of design and analysis of algorithms and data structures.