A. Tarski [22] proposed the study of infinitary consequence operations as the central topic of mathematical logic. He considered monotonicity to be a property of all such operations. In this paper, we weaken the monotonicity requirement and consider more general operations, inference operations. These operations describe the nonmonotonic logics both humans and machines seem to be using when infering defeasible information from incomplete knowledge. We single out a number of interesting families of inference operations. This study of infinitary inference operations (...) is inspired by the results of [12] on nonmonotonic inference relations, and relies on some of the definitions found there. (shrink)

In previous work, the author has shown that $\Pi ^1_1$ -induction along $\mathbb N$ is equivalent to a suitable formalization of the statement that every normal function on the ordinals has a fixed point. More precisely, this was proved for a representation of normal functions in terms of Girard’s dilators, which are particularly uniform transformations of well orders. The present paper works on the next type level and considers uniform transformations of dilators, which are called 2-ptykes. We show that $\Pi (...) ^1_2$ -induction along $\mathbb N$ is equivalent to the existence of fixed points for all 2-ptykes that satisfy a certain normality condition. Beyond this specific result, the paper paves the way for the analysis of further $\Pi ^1_4$ -statements in terms of well ordering principles. (shrink)

This paper explores the perversion of reality in the context of advanced technologies, such as AI, VR, and AR, through the lens of Jean Baudrillard’s theory of hyperreality and the precession of simulacra. By examining the transformative effects of these technologies on our perception of reality, with a particular focus on the usage of digital avatars, the paper highlights the blurred distinction between the real and the simulated, where the copy becomes more ‘real’ than the original. Drawing on Baudrillard’s concept (...) of hyperreality, the paper delves into the perversion of reality as individuals seek refuge in virtual pleasure paradises and embrace artificial pleasures through their digital avatars, disconnecting from genuine human experiences. The convergence of AI, VR, and AR technologies amplifies this hyperreal condition, where digital avatars mimic or surpass the depth of human relationships, challenging our understanding of what is real. In line with Baudrillard’s theory, the paper explores the objectification and commodification of reality within digital spaces, specifically examining the digital avatars’ role in the erosion of genuine human connections. It explores the implications of these avatars in terms of consent, exploitation, and loss of authenticity, echoing Baudrillard’s concerns about the distortion of reality in contemporary society. Recognizing the implications of these technologies, the paper calls for a critical reflection on their transformative power. It emphasizes the need for a nuanced understanding of the hyperreal condition and ethical responsibility in engaging with AI, VR, and AR, particularly in relation to the usage of digital avatars. By resisting the seductive allure of digital escapism and preserving genuine human connections, we can navigate the perversion of reality and cultivate empathy, compassion, and meaningful interactions that transcend the simulated experiences offered by technology. (shrink)

En estos tres artículos, que aparecen por primera vez en castellano, bosqueja el autor junto a una teoría general de la representación política, una relectura del problema permanente de la clasificación de los regímenes. Destaca en ellos particularmente el tratamiento de la cuestión de las causas de la corrupción de todas las formas de gobierno, incluida la democracia. Maquiaveliano riguroso y consciente, Freund no esquiva ninguno de los grandes problemas que siguen dividiendo hoy a quienes se acercan -no siempre (...) libres de prejuicios- a la realidad tantas veces poco complaciente de la política. (shrink)

Michael Rathjen and the present author have shown that ‐bar induction is equivalent to (a suitable formalization of) the statement that every normal function has a derivative, provably in. In this note we show that the base theory can be weakened to. Our argument makes crucial use of a normal function f with and. We shall also exhibit a normal function g with and.

This paper explores the intersection of René Girard's mimetic theory and the algorithmic society, particularly in the context of the potential advent of Artificial General Intelligence (AGI). Girard's theory, which elucidates the dynamics of desire, rivalry, scapegoating, and the sacrificial crisis, provides a unique lens through which to examine the complexities of our relationship with AI and its role in the creation of the sacred. As individuals increasingly rely on AI recommendations, the distinction between personal choice and algorithmic manipulation becomes (...) less clear, raising concerns about the authenticity of cultural expressions and the role of algorithms in shaping cultural narratives. The triangular structure of desire, with AI as the model and individuals as the imitators, underscores the power of algorithms in this process. The sacrificial crisis, a key concept in Girard's theory, becomes a critical point of reflection in the algorithmic society. The exposure of the scapegoating mechanism reveals the destructive potential of algorithmic manipulation and calls for new forms of understanding, empathy, and non-violent solutions. This paper argues that recognizing the sacrificial crisis can prompt individuals and society to critically examine the impact of AI's influence, challenge the narratives it perpetuates, and reclaim agency in the face of algorithmic dominance. This paper further discusses the potential implications of the emergence of AGI, which could intensify the influence of algorithms on the creation of the sacred due to its advanced cognitive capabilities and deep understanding of human desires and behaviors. This could fuel a rapid evolution of the mimetic ecosystem, with profound implications for personal freedom, independent decision-making, and the formation and preservation of individual identity. This paper concludes by emphasizing the need for responsible algorithmic practices and ethical considerations to ensure that the creation of the sacred serves the common good in the algorithmic society. (shrink)

In the context of reverse mathematics, effective transfinite recursion refers to a principle that allows us to construct sequences of sets by recursion along arbitrary well orders, provided that each set is ‐definable relative to the previous stages of the recursion. It is known that this principle is provable in. In the present note, we argue that a common formulation of effective transfinite recursion is too restrictive. We then propose a more liberal formulation, which appears very natural and is still (...) provable in. (shrink)

Logic and philosophy of logic have increasingly become areas of research and great interest in Latin America and Spain, where significant work has been done and continues to be done in both of these fields. The goal of this volume is to draw attention to this work through a collection of original and unpublished papers by specialists from Latin America and Spain. Some of the papers are of importance for set-theory and model theory. They cover topics such as the foundations (...) of paraconsistency, the use of paraconsistent logic as a basis for set-theory, and the methodological aspects in both the justification of new axioms in set theory and the formalization of pre-theoretic notions. Other papers are related to epistemic logic. They deal with the issues of abduction and the choice of the simplest hypothesis, the definition of group probability, and the nature of explanation and understanding in such logic. There are also papers on logical paradoxes, the semantics of names, and the nature of relations. Max A. Freund is Professor of Logic and Philosophy at the University of Costa Rica and the National University of Costa Rica. He is co-author of the book Modal Logic its syntax and semantics, as well as the author of Judicial Logic, and of a forthcoming book The Logic of Sortals. Max Fernandez de Castro is Professor of Logic and Philosophy at the Autonomous Metropolitan University of Mexico. He is the author of the book Quine y la Ontologíaa and co-author of the books Lógica Matemática I: lógica proposicional, intuicionista y modal, Lógica Matemática II: clásica, intuicionista y modal, Teoría de Conjuntos, Lógica y Temas Afines I. Marco Ruffino is Professor of Philosophy at the University of Campinas and the editor of Manuscrito, the Brazilian international journal for Analytic Philosophy. He has many publications, in important philosophical journals, in the philosophy of language, of logic, and of mathematics; in the history of analytic philosophy, and on Frege and Wittgenstein. (shrink)

Sortal concepts are at the center of certain logical discussions and have played a significant role in solutions to particular problems in philosophy. Apart from logic and philosophy, the study of sortal concepts has found its place in specific fields of psychology, such as the theory of infant cognitive development and the theory of human perception. In this monograph, different formal logics for sortal concepts and sortal-related logical notions are characterized. Most of these logics are intensional in nature and possess, (...) in addition, a bidimensional character. That is, they simultaneously represent two different logical dimensions. In most cases, the dimensions are those of time and natural necessity, and, in other cases, those of time and epistemic necessity. Another feature of the logics in question concerns second-order quantification over sortal concepts, a logical notion that is also represented in the logics. Some of the logics adopt a constant domain interpretation, others a varying domain interpretation of such quantification. Two of the above bidimensional logics are philosophically grounded on predication sortalism, that is, on the philosophical view that predication necessarily requires sortal concepts. Another bidimensional logic constitutes a logic for complex sortal predicates. These three sorts of logics are among the important novelties of this work since logics with similar features have not been developed up to now, and they might be instrumental for the solution of philosophically significant problems regarding sortal predicates. The book assumes a modern variant of conceptualism as a philosophical background. For this reason, the approach to sortal predicates is in terms of sortal concepts. Concepts, in general, are here understood as intersubjective realizable cognitive capacities. The proper features of sortal concepts are determined by an analysis of the main features of sortal predicates. Posterior to this analysis, the sortal-related logical notions represented in the above logics are discussed. There is also a discussion on the extent to which the set-theoretic formal semantic systems of the book capture different aspects of the conceptualist approach to sortals. These different semantic frameworks are also related to realist and nominalist approaches to sortal predicates, and possible modifications to them are considered that might represent those alternative approaches. (shrink)

It has been questioned whether it is at all possible to give the term “probability” one uniform and consistent interpretation not merely in mathematics, statistics, evaluation of evidence, testing of hypotheses but also in any situation where we want to express a degree of belief. The question itself of assigning a probability to our belief in a scientific theory has raised important questions of an epistemological as well as mathematical nature.

We shall distinguish between sortal predication and standard predication. The former kind of predication necessarily involves sortal concepts but the latter, as it is customarily viewed, does not. It is generally thought that the only essential occurrence of a concept in a standard predication is the concept being predicated. In this paper, we shall put forward an alternative view. We shall propose to understand standard predication as a cognitive act essentially requiring sortal concepts. We shall call this view conceptual predication (...) sortalism and ground it on the basis of epistemic-semantic reasons. Concepts are understood as intersubjectively realizable capacities or abilities that fulfill particular cognitive roles, such as those of classification, categorization, individuation, and referring. (shrink)

We propose a new intensional semantics for modal-tense second-order languages with sortal predicates. The semantics provides a variable-domain interpretation of the second-order quantifiers. A formal logical system is characterized and proved to be sound and complete with respect to the semantics. A contemporary variant of conceptualism as a theory of universals is the philosophical background of the semantics. Justification for the variable-domain interpretation of the second-order quantifiers presupposes such a conceptualist framework.

We develop a set-theoretic semantics for Cocchiarella's second-order logical system . Such a semantics is a modification of the nonstandard sort of second-order semantics described, firstly, by Simms and later extended by Cocchiarella. We formulate a new second order logical system and prove its relative consistency. We call such a system and construct its set-theoretic semantics. Finally, we prove completeness theorems for proper normal extensions of the two systems with respect to certain notions of validity provided by the semantics.

A formal logical system for sortal quantifiers, sortal identity and (second order) quantification over sortal concepts is formulated. The absolute consistency of the system is proved. A completeness proof for the system is also constructed. This proof is relative to a concept of logical validity provided by a semantics, which assumes as its philosophical background an approach to sortals from a modern form of conceptualism.

This paper investigates the responses of GPT-4, a state-of-the-art AI language model, to ten prominent philosophical paradoxes, and evaluates its capacity to reason and make decisions in complex and uncertain situations. In addition to analyzing GPT-4's solutions to the paradoxes, this paper assesses the model's Theory of Mind (ToM) capabilities by testing its understanding of mental states, intentions, and beliefs in scenarios ranging from classic ToM tests to complex, real-world simulations. Through these tests, we gain insight into AI's potential for (...) social reasoning and its capacity for more sophisticated forms of human-AI interaction. The paper also explores the limitations and biases of AI-generated reasoning and its implications for our comprehension of complex philosophical problems. (shrink)

In a recent paper by M. Rathjen and the present author it has been shown that the statement “every normal function has a derivative” is equivalent to $\Pi ^1_1$ -bar induction. The equivalence was proved over $\mathbf {ACA_0}$, for a suitable representation of normal functions in terms of dilators. In the present paper, we show that the statement “every normal function has at least one fixed point” is equivalent to $\Pi ^1_1$ -induction along the natural numbers.

This dissertation constitutes an inquiry into the formal aspects of a particular form of conceptual intentional realism: Holistic Realist Ramified Conceptualism. Several axiomatic systems, which have this theory as their philosophical background are developed and/or studied from a syntactical and semantical point of view. ;Among systems studied are Cocchiarella's RRC$\sbsp{\lambda}{\*}$ and HRRC$\sbsp{\lambda}{\*}$. A set theoretical semantics for these systems is developed. Also, completeness theorems with respect to certain extensions of RRC$\sbsp{\lambda}{\*}$ and HRRC$\sbsp{\lambda}{\*}$ and certain notions of validity related to that (...) semantics are proved. A relative consistency proof of RRC$\sbsp{\lambda}{\*}$, HRRC$\sbsp{\lambda}{\*}$ and other systems is given. ;An axiomatic system for identity free realist ramified conceptualism involving indiscernibility relative to constructive concepts is developed. A set theoretical semantics for this system is constructed. A completeness theorem with respect to certain extensions of the identity-free system and a notion of validity related to that semantics is proved. ;Epistemic considerations are brought into this inquiry by introducing an epistemic operator into the logical syntax. Such an operator corresponds intuitively to the idea of constructive knowability. A philosophical discussion of this idea is presented and on the basis of this discussion an epistemic logical theory is formulated. It is shown that this system has HRRC$\sbsp{\lambda}{\*}$ as a proper subsystem. On the basis of the epistemic logical theory, an axiomatic system is introduced from which Peano's arithmetic is deduced. In this way, it is shown that arithmetic can be developed axiomatically on conceptualist foundations. (shrink)

Composition is learned by discovering that musical ideas can be experienced in a variety of ways, and that new musical ideas can be created by reconfiguring learned materials in new contexts. The act of imagining, defining, and communicating unique musical ideas awakens in young people a dormant part of their brains, unlocking an awareness of the creative energy packed into every musical experience. This essay examines how the composition process can be exercised in classroom and ensemble projects that involve the (...) three stages of composition: (1) Defining the materials and limits; (2) Exploring the possibilities; (3) Making choices and communicating the resulting music through some sort of notation. Examples and strategies for implementing this process and for performing students' composition exercises are presented. The essay concludes with a checklist of suggestions for music educators as they guide students who wish to pursue composition as a career. (shrink)

"The Austin of the Jurisprudence of Administrative Law" This book originated as a series of lectures presented at Johns Hopkins in 1915. It proposes a method to supplement the established doctrine of constitutional law, which enforces legislative norms through negation and review, by a system of positive principles that would guide the making of statutes and give more definite meaning and content to the concept of due process. Highly regarded since its original publication in 1917 and the winner of Harvard (...) Law School's Ames Prize in 1919, it went on to become a standard work. It was recommended, to cite two examples, in Roscoe Pound's Introduction to American Law (1919) and Arthur Vanderbilt's Studying Law (1945). A comment published at the end of Freund's career summarizes a general opinion: "The great quality which Ernst Freund brought to the study of administrative law was his capacity for analysis. He was the Austin of the jurisprudence of administrative law." -W.I.J., Law Quarterly Review 49 (1933): 588. Ernst Freund [1864-1932] was Professor of Jurisprudence and Public Law at the University of Chicago. He is widely considered to be responsible for the development of administrative law in the United States. (shrink)

Let Con↾x denote the finite consistency statement “there are no proofs of contradiction in T with ≤x symbols.” For a large class of natural theories T, Pudlák has shown that the lengths of the shortest proofs of Con↾n in the theory T itself are bounded by a polynomial in n. At the same time he conjectures that T does not have polynomial proofs of the finite consistency statements Con)↾n. In contrast, we show that Peano arithmetic has polynomial proofs of Con)↾n, (...) where Con∗ is the slow consistency statement for Peano arithmetic, introduced by S.-D. Friedman, Rathjen, and Weiermann. We also obtain a new proof of the result that the usual consistency statement Con is equivalent to ε0 iterations of slow consistency. Our argument is proof-theoretic, whereas previous investigations of slow consistency relied on nonstandard models of arithmetic. (shrink)

Lange Zeit hat die Idee eines musikalischen Fortschritts gleichermassen fasziniert und polarisiert. Als zentraler Bestandteil der Diskurse um die Neue Musik verlangt sie nach einer differenzierten historischen Betrachtung. Anhand von reichhaltigem Textmaterial analysiert Julia Freund die zentralen Konzepte und Argumentationslinien und entwirft ein vielfältiges Panorama der Debatten der 1950er Jahre. Ausgangspunkt ist ein close reading der Schriften und Vorlesungen Theodor W. Adornos, dessen Fortschrittsbegriff im Rahmen seines philosophischen Projekts der Aufklärungskritik greifbar wird. In einem zweiten und dritten Schritt nimmt (...) die Autorin die Denkfiguren und Narrative der seriellen Komponisten (darunter K. Stockhausen und P. Boulez) sowie die Gegenentwürfe ihrer Kritiker (wie P. Hindemith oder Fr. Blume) in den Blick"--Back cover. (shrink)

Within legal contexts, a claim to knowledge requires that the evidence appealed to fulfills conditions established by legal norms that belong to the so-called Evidence Law. In addition, the epistemic justification presupposed by this kind of knowledge is temporally affected by the changing character of the evidence and the judicial discretion usually exercised in the applications of the Evidence Law. As such, these two scenarios involve three modalities: temporal, epistemic, and deontic. The present paper philosophically discusses the links between these (...) modal dimensions in the above legal context. Based on the discussion, a formal tense-epistemic-deontic logic is developed. That is, the paper characterizes a formal language formally representing the three dimensions through specific logical operators, constructs a formal semantics for the language, and specifies a formal logical system. Finally, the soundness and completeness of the system with respect to the semantics is proved. (shrink)