Resumen La encíclica Fratelli Tutti, centrada en el ideal de la fraternidad y la amistad, introduce una importante novedad en el magisterio social: la crítica tradicional al liberalismo y al socialismo, basada en la dignidad de la persona humana, es sustituida por una confrontación con los “populismos” y “liberalismos”, centrada en la noción de “pueblo”, que enfatiza la importancia de los vínculos sociales. Detrás de la prolijidad formal, sin embargo, los tres conceptos básicos del nue vo esquema no están adecuadamente (...) definidos. La identidad mítica del pueblo, que permite distinguir entre el líder “popular” y el “populista”, escapa a todo control racional; la equiparación del liberalismo con un individualismo extremo es una simplificación cuestionable y se omite toda referencia al socialismo y a sus peligros para los derechos fundamentales. un diálogo sin prejuicios con el pensamiento liberal aportaría una importante contribución a la sociedad abierta que este documento promueve.The Encyclical Fratelli Tutti, based on the ideal of fraternity and the construction of an open society, introduces an important novelty in the social magisterium: the traditional criticism against liberalism and socialism, based on the dignity of the human person, is replaced by a confrontation with “forms of populism and liberalism”, centered on the notion of “people”, stressing the importance of social bonds. Behind the formal neatness, however, the three basic concepts of this new framework are inadequately defined. The mythical identity of the people, which allows the distinction between the “popular” leader and the “populist” one, lays beyond any rational control; the equation of liberalism with extreme individualism is an oversimplification, and socialism is fully omitted despite the danger it represents to the fundamental rights. A dialogue without prejudices with the liberal thought would represent a meaningful contribution to the open society this text promotes. (shrink)

Resumen En su recepción del Concilio Vaticano II la Iglesia latinoamericana -focalizada en el problema de la pobreza-, tomó distancia de la teología del desarrollo planteada en Gaudium et spes y de la antropología subyacente, sea soslayando este concepto como expresión de la ideología “desarrollista”, sea neutralizando su relevancia a través de la expansión indefinida de su significado, y en todos los casos subordinándolo a la idea y el objetivo de la liberación. Pero su visión unilateral de la pobreza, que (...) interpreta como consecuencia virtualmente exclusiva de las “estructuras de pecado”, lleva inevitablemente a una visión maniquea de la vida social entendida en términos de antagonismo de clases, y empuja por su propia lógica a la acción revolucionaria. Al mismo tiempo, pasa por alto el desafío decisivo para derrotar la pobreza, que no es únicamente la mejor distribución de la riqueza sino también y ante todo su creación. En esto consiste el desarrollo económico, fenómeno moderno pero posibilitado por la capacidad de iniciativa e invención característica del ser humano como imagen de Dios. Mientras los caminos de liberación preconizados por la teología de la liberación y la teología del pueblo han fracasado de modo inapelable, el sistema económico, político y cultural que Michael Novak denominara “capitalismo democrático” es el único que ha demostrado y sigue demostrando capacidad efectiva para liberar las energías creadoras de la sociedad, permitiendo a los pobres prosperar y convertirse en artífices de su propio destino.After the Second Vanean Council, the theology of “development” presented by Gaudium et spes was overlooked in the Latín American Church in favor of the concept of "Uberalion”. Under-lying this option lay a unilateral vision of povery, conceived exclusively as the outcome of the “structures o/sin”. This diagnosis fostered class struggle and revolutionary action, while providing no clue as to how to overcome poverty through the creation of wealth. A more adequate approach should seek for institutional arrangements that provide conditions for both Beration and development. The social system of “democratic capitalism” is the only one capable of generating true economic development, making it possible for its citizens to display their creative energy and become protagonists of their own destiny. (shrink)

En este artículo presentaremos primero dos discusiones muy puntuales que confrontan a Badiou con Nancy y Lacan en torno al vacío y al infinito. Mostraremos después cómo pensamos que se articula el concepto, tanto en filosofía como en psicoanálisis, a la luz de dichas complejidades y de las imbricadas relaciones entre los diversos dispositivos de pensamiento que ellas implican. In this article we present first two arguments about the void and the infinity, confronting Badiou both with Nancy and Lacan. We (...) propose then an explanation of how the concept is articulated, both in philosophy and in psychoanalysis, in the light of such complexities and imbricated relationships among the diverse thinking dispostives that they imply. (shrink)

Com razão se costuma dizer que um problema bem posto é problema meio resolvido E o contrário também é verdade Ora, definir bem um termo tem grande analogia com pôr bem um problema- a correcta definição dos termos que usamos é condição indispensável para a adequada abordagem e debate de qualquer tema A ponto de Jaime Balmes ter podido dizer, com alguma dose de optimismo- si definimos no discutiremos Bem o sabiam os escolásticos, que por esse motivo faziam preceder qualquer (...) disputa pela fase ad terminos, na qual todos os termos que iriam utilizar eram cuidadosamente definidos A história da Ética dá-nos a conhecer alguns casos confirmativos, verdadeiramente exemplares, tanto da importância das definições exactas como das consequências negativas e dificuldades levantadas pelas formulações incorrectas Dois desses exemplos serão aqui lembrados- os dos problemas com que os moralistas se tiveram de confrontar em consequência das deficientes definições de mentira e mutilação A definição de mentira que vigorou durante séculos no mundo ocidental foi a que propôs S Agostinho, primeiro e quase único autor da Antiguidade a estudar desenvolvidamente o tema Este apaixonado pela verdade preocupou-se seriamente com a mentira, e não apenas por ela ser o oposto da verdade- também porque a sua própria concepção de mentira e, consequentemente, a definição que dela propôs, não se lhe apresentava isenta de dificuldades. (shrink)

RESUMEN En este texto argumento que la filosofía de Alain Badiou, al contrario de lo que se sostiene habitualmente, no es una ontologia matemática, ni un platonismo recidivo, ni un comunismo de la Idea, ni siquiera una teoría poscartesiana o poslacaniana del sujeto. En verdad, es todo eso junto y aún más. O lo que es lo mismo, es un montaje; un gran montaje o una gran ficción compuesta de heteróclitos fragmentos discursivos que se suplementan entre sí. La operación filosófica (...) pasa desapercibida entre ellos, aunque guarda su especificidad. ABSTRACT In this text, I will argue that the philosophy of Alain Badiou, contrary to what many believe, is not a mathematical ontology, nor a recurrence Platonism, neither communism of the Idea, and not even a post-Cartesian or post-lacanian theory of the subject. Is all together and more. Or what is the same thing: a montage. A great montage or a great fiction composed of diverse discursive fragments that supplement each other. (shrink)

AS IS WELL KNOWN, one of Kant's major concerns was the reconciliation of Newtonian science and metaphysics, a preoccupation made particularly acute by the need to provide a satisfactory explanation of organisms. It is in light of his claim that only the mechanistic principles of Newton's physics can provide scientific knowledge that the role to be played by purposiveness becomes problematic. Purpose appears to resist mechanistic explanation and is therefore a major impediment to unifying science under one set of principles. (...) Kant concludes that although organisms cannot be explained mechanistically, the impossibility is due to a limitation of reason. By appealing to the critical turn Kant thus avoids an antinomy between mechanism and finality while allowing that it is possible for mechanism and finality to be reconciled in the supersensible. This reconciliation, unfortunately, we will never know. (shrink)

La cohabitation avec la dialyse à domicile, ce lieu privé habituellement préservé de la maladie, invite à des questionnements sur la dynamique du couple au regard du nouveau rôle de soignant endossé par le conjoint et de celui de patient assigné au conjoint malade. Les auteurs, psychologues cliniciennes, interrogent ici les motivations conscientes et inconscientes qui conduisent à cette décision commune et leurs retentissements sur la dynamique du couple. Différentes configurations relationnelles observées dans notre clinique seront abordées. L’article, cas clinique (...) à l’appui, montre l’intérêt d’un groupe thérapeutique avec malades et conjoints pour mettre à jour les enjeux, au niveau de la relation de couple, d’une prise en charge à domicile. (shrink)

Apart from references to perception, words such asseeandlistenhave shared, non-literal meanings across diverse languages. Such cross-linguistic meanings have not been systematically investigated as they appear in their natural home — informal spoken interaction. We present a qualitative examination of the semantic associations of perception verbs based on recorded everyday conversation in thirteen diverse languages. Across these diverse communities, spontaneous interaction provides evidence for two commonly-discussed extensions of perception verbs — perception~cognition, hearing~linguistic communication — as well as illustrating other meanings and (...) functions (e.g., the use of perception verbs as discourse markers) that have been less appreciated heretofore. The range of usage that is readily observable in informal conversation makes it clear that this type of data must take center stage for the empirically grounded study of semantics. Moreover, these data suggest that commonalities in polysemous meanings may rely not only on universal cognition, but also on the universal exigencies of social interaction. (shrink)

In this article, I intend to link four topics or essential acts of philosophical practice: listening, caring, writing and transmitting, with special attention to children--what they inspire and teach us about philosophical practice, with special attention to the situation of confinement caused by the Covid-19 pandemic. A first task is to recover the function of listening and desire, in the context of the concept and the game, and against any abuse or violence. Second, we emphasize the role of care--its expansion (...) and reformulation in these difficult circumstances, especially in interrupting the logic of servitude and of the activity-debt-reward circuit by way of the pleasure of inquiry. Third, we practice writing as a technology of self that overcomes the dichotomy between personal and academic form, in order to become a practice of care and transmission, along with other self-practices: abstinence, self-examination, exercises, etc. Finally, we consider the question of the “Name of the Father”--how to understand the decline of patriarchy in relation to love, self-esteem, the transmission and the use of a symbolic legacy, given that the decline in question is not merely a weakening, but an unfolding of a singular-generic power that binds us together: learning to decline names, words, concepts, and traditions, which is what drives true subject formation. (shrink)

El problema radica en la imprecisión del tipo de justicia adoptado en las Constituciones Políticas de América del Sur; tal ausencia genera que el sistema de justicia y la igualdad social sean implementados de forma inadecuada. La finalidad es proponer la aplicación de la justicia conmutativa en la administración de justicia y la justicia distributiva en la igualdad. La metodología utilizada es el enfoque cuantitativo, diseño transeccional, descriptivo. Los resultados presentan desacuerdo y desconfianza en el sistema de justicia y que (...) la falta de precisión del tipo de justicia genera incremento de la desigualdad social y crisis económica. (shrink)

Words that describe sensory perception give insight into how language mediates human experience, and the acquisition of these words is one way to examine how we learn to categorize and communicate sensation. We examine the differential predictions of the typological prevalence hypothesis and embodiment hypothesis regarding the acquisition of perception verbs. Studies 1 and 2 examine the acquisition trajectories of perception verbs across 12 languages using parent questionnaire responses, while Study 3 examines their relative frequencies in English corpus data. We (...) find the vision verbs see and look are acquired first, consistent with the typological prevalence hypothesis. However, for children at 12–23 months, touch—not audition—verbs take precedence in terms of their age of acquisition, frequency in child‐produced speech, and frequency in child‐directed speech, consistent with the embodiment hypothesis. Later at 24–35 months old, frequency rates are observably different and audition begins to align with what has previously been reported in adult English data. It seems the initial orientation to verbalizing touch over audition in child–caregiver interaction is especially related to the control of physically and socially appropriate behaviors. Taken together, the results indicate children's acquisition of perception verbs arises from the complex interplay of embodiment, language‐specific input, and child‐directed socialization routines. (shrink)

El texto presenta tres dimensiones de uso posibles del pensamiento foucaultiano, en relación a la perspectiva latinoamericana de quien escribe, para situar el presente: la racionalidad política, la ética materialista y la ontología crítica. Esta perspectiva se inscribe en un programa de investigación en el que ya ha publicado varios avances al respecto. Luego se detiene a considerar el concepto pragmático de verdad como factor de anudamiento de estas tres dimensiones, y concluye con un posible diagnóstico acerca de porqué resulta (...) tan difícil -pero indispensable- en la actualidad hacer uso del pensamiento foucaultiano en el sentido señalado. (shrink)

Evoca-se neste artigoo P. António Alves Durão enquanto professor de filosofia, desenvolvendo especialmente a partir de duas temáticas da sua docência - a mentira e a sociedade mundial - as suas qualidades de mestre eminente. /// Cet article évoque le Père António Alves Durâo en tant que professeur de philosophie, en développant spécialement à partir de deux thématiques de son enseignement - le mensonge et la société mondiale - ses qualités de maître éminent. /// This article recalls Father António Alves (...) Durão, in his role as professor of philosophy. It seeks to describe his pedagogical qualities with special reference to two themes: lying and word society. (shrink)

Com base na correspondência entre Gabriel Marcel e Gaston Fessard, recentemente publicada, dão-se a conhecer alguns aspectos da personalidade e da obra de G. Marcel. /// Sur la base de la correspondance entre Gabriel Marcel et Gaston Fessard, récemment publiée on en vient à découvrir quelques traits de la personnalité et de l'oeuvre de G. Marcel. /// The recently published correspondence between Gabriel Marcel and Gaston Fessard gives some light on Marcel's personality and work.

En este escrito retomo y complejizo indagaciones anteriores sobre el método filosófico, y explicito su vinculación con el concepto de sujeto desde una perspectiva posfundacional. Se trata de dar cuenta de un trabajo en curso y del trazado singular en el cual he ido desplegando, entre diversos autores, mi propia perspectiva teórica acerca de estos tópicos entrelazados. Estas elaboraciones responden no sólo a una necesidad teórica o epistémica, sino a una inquietud ético-política —es decir crítica— por el presente. Claramente me (...) inscribo en el cultivo de aquel ethos crítico que Foucault rescata de la Ilustración y que consiste en enlazar las indagaciones epistémicas a consideraciones éticas y políticas al mismo tiempo, lo que constituye una ontología crítica del presente. En este caso, excediendo las elaboraciones del propio Foucault y vinculándolas a otros autores, como Badiou y Althusser. (shrink)

This paper argues that, for Ockham, the parts of the continuum exist in act in the continuum: they are already there before any division of the continuum. Yet, they are infinitely many in that no division of the continuum will exhaust all the existing parts of the continuum taken conjointly. This reading of Ockham takes into account the crucial place of his new concept of the infinite in his analysis of the infinite divisibility of the continuum. Like many of his (...) fellow anti-atomists, Ockham stresses that the concept of a potential infinite seems to contradict Aristotle’s modal logic, in particular the central assumption that there is no potency that will never be realized. Ockham, like other fourteenth-century anti-atomists, tried not only to refute atomism, but also to propose an analysis of the infinite divisibility of the continuum that is not incompatible with their modal logic. (shrink)

This paper critically examines the debate between William of Ockham and his contemporary Peter Auriol on how to account for the intension and remission of forms. Peter Auriol denies that an added degree of a quality such as the theological virtue of charity could be anything other than something which is neither a universal nor an individual and which cannot be grasped by intuition, but must be posited in order to account for the possibility that an accidental form can vary (...) in intensity. Ockham aims at proving that Auriol’s account is inconsistent. In my opinion, Ockham does not succeed, nor does he succeed in defending a consistent account of the metaphysics underlying the intension and remission of forms. Indeed, he conceives of the degree of a quality as a part of the intensified quality which, while being an individual that is really distinct from the quality and can be picked out, forms a unity with it in such a way that the union of the degree and the quality is itself an individual. Ockham fails to distinguish the notion of maximal resemblance holding between a quality’s degree and the quality from the notion of maximal resemblance which holds between individuals of the same species. In the end, he is led to give up the idea that a degree is an individual that can be picked out in order to protect the core thesis of his nominalism about universals. (shrink)

En el presente artículo efectuamos una lectura crítica de distintos posicionamientos teóricos respecto a la posibilidad —o no— de una filosofía materialista. Para ello tratamos de circunscribir la especificidad de una práctica teórica que dé cuenta de otras prácticas (teóricas o no) sin reducirlas a un lenguaje homogéneo o explicarlas desde un metalenguaje. En este recorrido vamos presentando entonces distintas perspectivas que permitirán ir desplegando nuestro propio punto de vista en torno a la posibilidad —o no— de una práctica filosófica (...) de tal índole. (shrink)

English summary: This book attests that a study on the history of philosophy has its place in contemporary debates. This book attempts to reconstruct William of Ockham's position on the nature and function of real definitions in order to show that nominalism does not oblige a particular position on essences. French description: Guillaume d'Ockham, defenseur bien connu du nominalisme, a manifeste un interet soutenu pour les definitions reelles. Cet ouvrage s'efforce de reconstruire sa position sur la nature et la fonction (...) des definitions reelles. Un examen de ce qu'est une definition reelle appelle une etude de ce qu'est une essence et de la nature du lien a poser entre l'essentiel et le necessaire. Cet ouvrage a pour objectif de montrer que le nominalisme ne contraint pas a une position determinee sur les essences. Saul Kripke nous dit que l'essentiel se reduit au necessaire. Kit Fine, par contre, affirme qu'il faut revenir a Aristote et soutenir que l'essentiel est irreductible au necessaire. Notre examen atteste qu'une etude en histoire de la philosophie a toute sa place dans les debats contemporains. L'essentialisme de Guillaume d'Ockham incite a rendre a Aristote ce qui lui revient et a faire preuve de circonspection. En definitive, les deux positions en presence ne sont peut-etre pas incompatibles. (shrink)

O texto apresenta e discute um entendimento de aprendizagem que se fundamenta na linguagem e na pesquisa. Defendendo que todo aprender constitui a reconstrução de algo já anteriormente aprendido, argumenta-se que a aceitação disso exige valorizar a linguagem e a pesquisa como elementos centrais nos processos de ensinar e de aprender. Mostra-se, ainda, que assumir esses entendimentos possibilita tornar as aprendizagens mais significativas, criando oportunidades aos alunos de se assumirem em suas autorias na reconstrução dos discursos sociais, e, assim, qualificar (...) politicamente todo o processo. (shrink)

The overwhelming majority of action theories have relied on a Humean model of causality and of explanation; even those theories that explicitly reject aspects of that model uncritically adopt others. The atomistic presuppositions embodied in the model are unable to account for either the dynamic and fabric-like nature of action or the features of control and meaning present therein. It is these atomistic presuppositions that give rise to the “Gettier-like vexations” that are common counterexamples in action theory. The Humean requirement (...) that cause and effect be only contingently connected and generalizable into a covering law is also discussed with respect to the explanation of action.Representatives of the three major approaches to the problem of action: causal (including intentional, volitional, as well as agent causation and reasons-as-causes theories), behaviorist, so-called “contextual”, and teleological theories are examined. (shrink)

The chapter published in the book ‘Contingency and Natural Order in Early Modern Science’, pages 27–59, https://doi.org/10.1007/978-3-319-67378-3_3, has been retracted because it contains significant parts plagiarizing another publication.

A partir de un recuento del movimiento teatral en El Salvador durante la efervescencia revolucionaria de la década de 1970, el presente artículo discute distintas estéticas teatrales de vanguardia preocupadas por desarrollar un pensamiento desde el cuerpo. Examinando los conceptos centrales del teatro épico de Brecht y sus continuadores latinoamericanos y enmarcándolos en el debate estético sobre sus implicaciones, intenta mostrar que el nuevo teatro pone en evidencia la producción social del cuerpo como mecanismo de subjetivación y las posibilidades de (...) emancipación que se abren a través de las nuevas formas de experimentarlo que ofrecen los nuevos vocabularios dramáticos. (shrink)

Este artículo se ocupa de parte de la historia del electrón entre 1928 (aparición de la ecuación del electrón de Dirac) y 1947-49 (reformulación de la electrodinámica cuántica). Durante este período la física del electrón experimenta cambios sustanciales, entre los que destaca el descubrimiento de la primera antipartícula, el positrón, y la trabajosa elaboración de la teoría que seguimos utilizando para describir al electrón y sus interacciones. Son dos décadas cruciales no ya para la física del electrón, sino para la (...) física entera, que se industrializa y militariza. (shrink)

Theory change is a central concern in contemporary epistemology and philosophy of science. In this paper, we investigate the relationships between two ongoing research programs providing formal treatments of theory change: the (post-Popperian) approach to verisimilitude and the AGM theory of belief change. We show that appropriately construed accounts emerging from those two lines of epistemological research do yield convergences relative to a specified kind of theories, here labeled “conjunctive”. In this domain, a set of plausible conditions are identified which (...) demonstrably capture the verisimilitudinarian effectiveness of AGM belief change, i.e., its effectiveness in tracking truth approximation. We conclude by indicating some further developments and open issues arising from our results. (shrink)

To what extent does perceptual language reflect universals of experience and cognition, and to what extent is it shaped by particular cultural preoccupations? This paper investigates the universality~relativity of perceptual language by examining the use of basic perception terms in spontaneous conversation across 13 diverse languages and cultures. We analyze the frequency of perception words to test two universalist hypotheses: that sight is always a dominant sense, and that the relative ranking of the senses will be the same across different (...) cultures. We find that references to sight outstrip references to the other senses, suggesting a pan-human preoccupation with visual phenomena. However, the relative frequency of the other senses was found to vary cross-linguistically. Cultural relativity was conspicuous as exemplified by the high ranking of smell in Semai, an Aslian language. Together these results suggest a place for both universal constraints and cultural shaping of the language of perception. (shrink)

Este artículo es parte de un trabajo de investigación bastante más amplio, que llevó casi cinco años de duración, en el cual nos propusimos una lectura rigurosa como singular del concepto de sujeto en Alain Badiou y Jacques Lacan. En vistas a delimitar claramente el tema de estudio, la pregunta que nos formulamos como punto de partida fue la siguiente: ¿qué lugar ocupa el concepto de sujeto en la articulación lógica del pensamento de ambos autores, particularmente en sus dimensiones ontológicas (...) y políticas? Como se podrá apreciar a continuación, dicho trabajo despliega una topología conceptual que a su vez presenta ciertos hitos históricos. Pues es sabido que uno de los temas centrales en torno al cual ha girado la fi losofía política contemporánea ha sido la cuestión del sujeto, y así también, correlativamente, de los saberes y verdades que lo fundamentan. Se ha interrogado por ejemplo ¿cuál puede ser el lugar de este sujeto? ¿Es posible especifi car a priori su existencia? ¿De dónde deriva su estatuto? ¿Se trata de una función trascendental o sustancial, vacía o refl exiva? Estas preguntas responden, en cierta forma, a una concepción de sujeto más bien propia de la metafísica moderna que intentaremos desplazar. (shrink)

En este escrito realizo en nombre propio un punto de pasaje y conjunción entre Foucault y Spino-za. Tomo en función de ello a Lacan como “mediador evanescente” y produzco un desplazamiento en el plano teórico habilitado por la urgencia de la coyuntura política, signada esta por el neolibe-ralismo y su posible dislocación, para engarzar el planteo crítico a la ética y a una necesaria refor-ma del entendimiento que active los afectos. Motiva y avala esta composición conceptual un trabajo teórico y (...) práctico sostenido que ha venido desplegándose sistemáticamente en torno al pensamien-to llamado posfundacional. (shrink)

El texto presenta la perspectiva de la filósofa y científica Vinciane Despret a partir de cuatro tópicos que se intersecan y atraviesan diferencialmente todas sus investigaciones: heredar, interesar, confiar, sostener. Esta delimitación permite acentuar distintas modulaciones del ethos investigativo que nos propone y amplificar la originalidad de su apuesta al hacerla dialogar con otras perspectivas filosóficas que resultan afines a ella y no son explicitadas por la autora (Spinoza, Foucault). Considero que la perspectiva de Despret condensa de manera ejemplar las (...) principales líneas de un ethos de investigación que despierta el deseo de sostenerlo saliendo de las encrucijadas actuales donde normalmente se lo aplasta o desprecia. En la introducción aclaro por qué me centro en la perspectiva de esta autora en particular, y en las consideraciones finales sugiero un enlace con mi propia propuesta de investigación que vengo desarrollando hace tiempo. (shrink)

Nesta comunicação pretende-se desenvolver a relação entre violência e política enquadrada no pensamento de Hannah Arendt e a partir de duas obras fundamentais, On Revolution (1963) e On Violence (1970). Investigando-se sobre o que constitui cada experiência em particular, a da violência (ainda que sob a forma da guerra ou da revolução) e a da política, esta relação permitirá equacionar criticamente as possibilidades e os limites das sociedades democráticas actuais como o resultado da tradição política e das revoluções da modernidade.

In contrast to the robust mutual interpretability phenomenon in set theory, Ali Enayat proved that bi-interpretation is absent: distinct theories extending ZF are never bi-interpretable and models of ZF are bi-interpretable only when they are isomorphic. Nevertheless, for natural weaker set theories, we prove, including Zermelo–Fraenkel set theory $\mathrm {ZFC}^{-}$ without power set and Zermelo set theory Z, there are nontrivial instances of bi-interpretation. Specifically, there are well-founded models of $\mathrm {ZFC}^{-}$ that are bi-interpretable, but not isomorphic—even $\langle H_{\omega _1},\in (...) \rangle $ and $ \langle H_{\omega _2},\in \rangle $ can be bi-interpretable—and there are distinct bi-interpretable theories extending $\mathrm {ZFC}^{-}$. Similarly, using a construction of Mathias, we prove that every model of ZF is bi-interpretable with a model of Zermelo set theory in which the replacement axiom fails. (shrink)