The Air Quality Index (AQI) shows the state of air pollution in a unique and more understandable way. This work aims to forecast the AQI in Algeciras (Spain) 8 hours in advance. The AQI is calculated indirectly through the predicted concentrations of five pollutants (O3, NO2, CO, SO2 and PM10) to achieve this goal. Artificial neural networks (ANNs), sequence-to-sequence long short-term memory networks (LSTMs) and a newly proposed method combing a rolling window with the latter (LSTMNA) are employed as the (...) forecasting techniques. Besides, two input approaches are evaluated: using only the data from the own time series of the pollutant in the first case or adding exogenous variables in the second one. Several window sizes are employed (24, 28 and 72 hours) with ANNs and LSTMNAs. Additionally, several feature ranking methods are applied in the exogenous approach to select the most relevant lagged variables to feed the models. Results show how the proposed exogenous approach increases the performance of the prediction models. Besides, the newly proposed method LSTMNA provides the best performances in most of the cases evaluated. Hence, it constitutes an exciting alternative to standard LSTMs and ANNs to predict pollutants concentrations and, consequently, the AQI. (shrink)

Participar del món es deté en alguns dels temes clau sobre els quals la filòsofa Hannah Arendt va escriure entre 1941 i 1945 a la revista estatunidenca Aufbau: la gratitud, les figures jueves de la pària i la forana, l’autoemancipació i la qüestió jueva i àrab a Palestina. Participar del món no sols té el valor de rescatar el desconegut perfil sionista d’Hannah Arendt, sinó que també és la primera traducció íntegra dels articles publicats a Aufbau i de les actes (...) del Jove Grup Jueu que Arendt va posar a funcionar el 1942. (shrink)

While punishment is a longstanding object of philosophical scrutiny, other controversial aspects of the justice system, such as policing, have flown under the radar. In this paper, we consider possible reasons why philosophers interested in crime and punishment have neglected policing. We make the case for a broader account of the political morality of the justice system, with a particular emphasis on policing. We sketch the outlines of an egalitarian version of such a theory, highlighting parallels between policing and the (...) welfare state. Finally, we turn to recent calls for police abolition. Evaluating such radical claims requires, we argue, going beyond the traditional confines of the philosophy of punishment and considering a more holistic and interdisciplinary theory of criminal justice. (shrink)

Este trabajo se trata de un estudio sobre el régimen legal de las garantías en la contratación pública venezolana, su especialidad, los tipos de garantías, las formas de otorgarlas y su ejecución. Adicionalmente se comenta el régimen sancionatorio vinculado a las garantías contractuales, y por último, se hace una pequeña referencia a los tipos de garantías previstos en el régimen de compras públicas en España.

The aim of this paper is to provide a complete Natural Kind Semantics for an Essentialist Theory of Kinds. The theory is formulated in two-sorted first order monadic modal logic with identity. The natural kind semantics is based on Rudolf Willes Theory of Concept Lattices. The semantics is then used to explain several consequences of the theory, including results about the specificity (species–genus) relations between kinds, the definitions of kinds in terms of genera and specific differences and the existence of (...) negative kinds. First, I show under which conditions the Hierarchy principle, which has been subjected to counterexamples in the literature, holds. I also show that a different principle about the species–genus relations between kinds, namely Kant’s Law, follows from the essentialist theory. Second, I introduce two new operations for kinds and show that they can be used to provide traditional definitions of kinds in terms of genera and specific differences. Finally, I show that these operations of specific difference induce, for each kind, a uniquely specified contrary kind and a uniquely specified subcontrary kind, which can be used as semantic values for non-classical predicate negations of kind terms. (shrink)

Understanding the changes in our language abilities along the lifespan is a crucial step for understanding the aging process both in normal and in abnormal circumstances. Besides controlled experimental tasks, it is equally crucial to investigate language in unconstrained conversation. I present an information-theoretical analysis of a corpus of dyadic conversations investigating how the richness of the vocabulary, the word-internal structure, and the syntax of the utterances evolves as a function of the speaker's age and sex. Although vocabulary diversity increases (...) throughout the lifetime, grammatical diversities follow a different pattern, which also differs between women and men. Women use increasingly diverse syntactic structures at least up to their late fifties, and they do not deteriorate in terms of fluency through their lifespan. However, from age 45 onward, men exhibit a decrease in the diversity of the syntactic structures they use, coupled with an increased number of speech disfluencies. (shrink)

Trabajar por la construcción de la paz, promover una educación de calidad para todos, y conceder mayor atención a las necesidades especiales de los países en situaciones de conflicto y crisis, son tres de los diecisiete objetivos de la Agenda 2030 de la Unesco. Pero ¿Quién y cómo lo hará posible? Tenemos una tarea. Hoy, aquí, desde este escenario que promueve el libre pensamiento desde la filosofía teórica y práctica, estamos haciendo una parte de la tarea. Si no lo hacemos (...) nosotros o pensamos que no se puede hacer, alguien más lo hará. A través de la historia muchos han sido los pensadores, cuya inspiración ha trascendido en el tiempo, llamando nuestra atención, causando reflexión, y hasta molestia. El primero va dirigido a quienes somos conscientes de que la educación de calidad solo es posible en un entorno de paz, y, el segundo señala a quienes la paz les incomoda, el concepto de educación les es indiferente, pero el de turbulencia les suena más familiar. (shrink)

En el Gorgias, Platón distingue el modo de ser y actuar propio del filósofofrente al modo de ser y actuar propio del retórico. Para esto, usa comocriterio a la misma retórica a partir de la distinción retórica aduladora – retóricacientífica. Frente a esto, Aristóteles realiza una toma de posición quereformula las críticas platónicas referentes a la posibilidad de una technêretórica. El presente texto confrontara las condiciones que según el Gorgiasdebe cumplir la retórica para llegar a ser technê con las características (...) que,según Aristóteles, tiene la retórica a partir de su relación con la dialéctica. (shrink)

Este libro es un estudio sobre las teor as del desarrollo social y un an lisis de las estrategias, instituciones y pol ticas econ micas de los ltimos tiempos en varios pa ses.

El ser humano se ha debatido entre lo que ha creído, cree y seguirá creyendo; pero, particularmente sobre la existencia de Dios, lo hace a su conveniencia. Cuando observan la naturaleza o el universo pueden preguntarse si surgió de una explosión hace millones de años o es creación de Dios. Filósofos, científicos y personas del común siguen buscando respuestas a sus preguntas. Es “el hombre en busca de sentido como lo propone Víctor Frank, y agrega, que, … hay en él (...) [en el hombre] una espiritualidad inconsciente: la presencia ignorada de Dios”. Es el ser humano que ha decidido ignorar, poner en duda, o negar radicalmente, la existencia de Dios, más aún cuando el mal prevalece en el mundo. No se podría negar la existencia de algo, o de alguien, que no existe. “Nadie niega a Dios, sino aquel a quien no le conviene que Dios exista” (Agustín de Hipona). “Es un nuevo ateísmo enfrentando la fe y la razón” (Antonio Cruz). “La existencia de Dios es evidente en sí misma” (Tomas de Aquino). “Tiene que haber una causa inexorable de lo creado… y ese ser sería Dios” (Aristóteles). “Mi conciencia está ligada a la palabra de Dios” (Martin Lutero). “… desde la creación del mundo conocieron a Dios, pero no quisieron adorarlo como Dios ni darle gracias. En cambio, comenzaron a inventar ideas necias sobre Dios” (Romanos 1). “Yo Soy el que Soy” (Éxodo 3:14), así define Dios Su propia existencia, creíble y conveniente. (shrink)

Bourrat and Griffiths :33, 2018) have recently argued that most of the evidence presented by holobiont defenders to support the thesis that holobionts are evolutionary individuals is not to the point and is not even adequate to discriminate multispecies evolutionary individuals from other multispecies assemblages that would not be considered evolutionary individuals by most holobiont defenders. They further argue that an adequate criterion to distinguish the two categories is fitness alignment, presenting the notion of fitness boundedness as a criterion that (...) allows divorcing true multispecies evolutionary individuals from other multispecies assemblages and provides an adequate criterion to single out genuine evolutionary multispecies assemblages. A consequence of their criterion is that holobionts, as conventionally defined by hologenome defenders, are not evolutionary individuals except in very rare cases, and for very specific host-symbiont associations. This paper is a critical response to Bourrat and Griffiths’ arguments and a defence of the arguments presented by holobiont defenders. Drawing upon the case of the hologenomic basis of the evolution of sanguivory in vampire bats, I argue that Bourrat and Griffiths overlook some aspects of the biological nature of the microbiome that justifies the thesis that holobionts are evolutionarily different to other multispecies assemblages. I argue that the hologenome theory of evolution should not define the hologenome as a collection of genomes, but as the sum of the host genome plus some traits of the microbiome which together constitute an evolutionary individual, a conception I refer to as the stability of traits conception of the hologenome. Based on that conception I argue that the evidence presented by holobiont defenders is to the point, and supports the thesis that holobionts are evolutionary individuals. In this sense, the paper offers an account of the holobiont that aims to foster a dialogue between hologenome advocates and hologenome critics. (shrink)

Contemporary biological research has suggested that some host–microbiome multispecies systems (referred to as “holobionts”) can in certain circumstances evolve as unique biological individual, thus being a unit of selection in evolution. If this is so, then it is arguably the case that some biological adaptations have evolved at the level of the multispecies system, what we call hologenomic adaptations. However, no research has yet been devoted to investigating their nature, or how these adaptations can be distinguished from adaptations at the (...) species-level (genomic adaptations). In this paper, we cover this gap by investigating the nature of hologenomic adaptations. By drawing on the case of the evolution of sanguivory diet in vampire bats, we argue that a trait constitutes a hologenomic adaptation when its evolution can only be explained if the holobiont is considered the biological individual that manifests this adaptation, while the bacterial taxa that bear the trait are only opportunistic beneficiaries of it. We then use the philosophical notions of emergence and inter-identity to explain the nature of this form of individuality and argue why it is special of holobionts. Overall, our paper illustrates how the use of philosophical concepts can illuminate scientific discussions, in the trend of what has recently been called metaphysics of biology. (shrink)

Symbiosis plays a fundamental role in contemporary biology, as well as in recent thinking in philosophy of biology. The discovery of the importance and universality of symbiotic associations has brought new light to old debates in the field, including issues about the concept of biological individuality. An important aspect of these debates has been the formulation of the hologenome concept of evolution, the notion that holobionts are units of natural selection in evolution. This review examines the philosophical assumptions that underlie (...) recent proposal of the hologenome concept of evolution, and traces those debates back in time to their historical origins, to the moment when the connection between the topics of symbiosis and biological individuality first caught the attention of biologists. The review is divided in two parts. The first part explores the historical origins of the connection between the notion of symbiosis and the concept of biological individuality, and emphasizes the role of A. de Bary, R. Pound, A. Schneider and C. Merezhkowsky in framing the debate. The second part examines the hologenome concept of evolution and explores four parallelisms between contemporary debates and the debates presented in the first part of the essay, arguing that the different debates raised by the hologenome concept were already present in the literature. I suggest that the novelty of the hologenome concept of evolution lies in the wider appreciation of the importance of symbiosis for maintaining life on Earth as we know it. Finally, I conclude by suggesting the importance of exploring the connections among contemporary biology, philosophy of biology and history of biology in order to gain a better understanding of contemporary biology. (shrink)

Given one conception of biological individuality (evolutionary, physiological, etc.), can a holobiont – that is the host + its symbiotic (mutualistic, commensalist and parasitic) microbiome – be simultaneously a biological individual and an ecological community? Herein, we support this possibility by arguing that the notion of biological individuality is part‐dependent. In our account, the individuality of a biological ensemble should not only be determined by the conception of biological individuality in use, but also by the biological characteristics of the part (...) of the ensemble under investigation. In the specific case of holobionts, evaluations of their individuality should be made either host‐relative or microbe‐relative. We support the claim that biological individuality is part‐dependent by drawing upon recent empirical evidence regarding the physiology of hosts and microbes, and the recent characterization of the ‘demibiont’. Our account shows that contemporary disagreements about the individuality of the holobiont derive from an incorrect understanding of the ontology of biological individuality. We show that collaboration between philosophers and biologists can be very fruitful in attempts to solve some contemporary biological debates. (shrink)

According to the cohabitation account, all the persons that result from a fission event cohabit the same body prior to fission. This article concerns a problem for this account. Suppose Manuel and Jimena are suffering from an equally painful migraine. Unlike Jimena, however, Manuel will undergo fission. Assuming you have a spare painkiller, whom should you give it to? Intuitively, you have no more reason to give it to one or the other. The problem is that the cohabitation account suggests (...) otherwise. According to the account, there are two persons cohabiting Manuel’s body, in which case you should arguably give them the pill, since doing so alleviates the pain of more beings. One response argues that the two persons cohabiting Manuel’s body share one pain. Thus, giving them the pill alleviates no more pain than giving it to Jimena, and therefore you have no more reason to do one or the other. The goal of this article is to show that this response fails. (shrink)

Este estudio es una aproximación al tema del trabajo desde el pensamiento sociológico de Zygmunt Bauman. Uno de los textos más conocidos de Bauman al respecto es Trabajo, consumismo y nuevos pobres; sin embargo, este es un tema que el sociólogo trata en otras obras. Aquí se pretende dar una visión en la que se tienen en cuenta la globalidad de sus escritos. Además, se dan unas claves que permiten comprender el enfoque que Bauman tiene del trabajo: se hace una (...) breve explicación de su perspectiva sociológica y de la importancia de la modernidad en su pensamiento. Por último, se expone cómo el trabajo cambia de sentido e importancia en la modernidad sólida y en la líquida. (shrink)

Lewis has objected to Armstrong's notion of a structural universal on the grounds that it violates the Principle of Uniqueness of Composition, which says that given some parts, there is only one whole that they compose. This paper reviews Armstrong's case for structural universals, and then attempts to reconcile structural universals with PUC by arguing for the existence of arrangement universals. The latter are not only a key to defending structural universals against Lewis' objection, but are in fact essential to (...) Armstrong's conception of structural universals in general. Three objections to my proposal are deflected, and two alternative proposals are shown to be inferior to it. (shrink)

El propósito de este artículo es desarrollar una relectura al mecanicismo moderno. Esto implica que una adecuada comprensión de este consiste, ante todo, en considerarlo como un proyecto antes que un sistema doctrinal consolidado. Para ello se toma como eje la filosofía de Leibniz, la cual, a diferencia del cartesianismo, identifica las inconsistencias que implica concebir el mecanicismo como un sistema filosófico completo, principalmente al pretender justificar mecánicamente el mundo natural, esto es, a partir de la figura, el tamaño y (...) el movimiento. Todo lo anterior no implica un rechazo completo del mecanicismo por parte de Leibniz, sino que permite concebirlo como un medio para desarrollar su filosofía, proponiendo una complementariedad entre la causa final y la causa eficiente. de este modo, el mecanicismo es reubicado como un problema metodológico para la ciencia natural antes que como un problema metafísico. This article aims to develop a second reading to the modern mechanicism. This implies that an appropriate understanding of mechanicism consists, above all, in considering it as a project, instead of a consolidated doctrinal system. To do so, we take Leibniz's philosophy as our building blocks, since unlike the Cartesianism, it does identify the inconsistencies implied when we conceive mechanicism as a complete philosophical system, mainly under the pretension to justify the natural world mechanically, that is, based on the figure, size and movement. It does not imply that Leibniz rejects entirely mechanicism, but allows us to understand it as a mean to develop his philosophy, proposing a complementary relationship between final cause and efficient cause. This way, mechanicism is re-posed as a methodological issue for the natural science instead of a metaphysical issue. (shrink)

Este estudio se centra en el recorrido y desarrollo de Mario Conde, detective protagonista de las ocho novelas policiales del escritor cubano Leonardo Padura. De la tetralogía que se inicia con Pasado Perfecto,en 1991, hasta la ambiciosa y última entrega de Herejes, en 2013, Conde actúa mayormente dentro del “período especial” cubano marcado por la debacle de la Unión Soviética, para arribar a la primera década del siglo XXI. Dicho “período especial” produjo un quiebre en el desarrollo del género policial (...) en Cuba. Por lo tanto, el género policial revolucionario, con apoyo oficial que nace a comienzos de la década de los 70, se transforma en los 90 para insertarse en la vertiente neopolicial que el resto de Latinoamérica venía desarrollando desde una década antes.Lejos de los personajes modélicos revolucionarios del género en su origen, el neopolicial de Padura crea personajes que resuelven crímenes y delitos pero a la vez delinquen y evaden la ley. A partir de los casos que investiga, Conde se mueve dentro de esa paradójica conducta, al mismo tiempo que deconstruye y desmitifica las grandes políticas y discursos revolucionarios. (shrink)

The paper defends an interactive theory of the distinctiveness of criminal law. It argues that criminal law’s distinctive behavior can be connected to the interaction between five traits: it is an institutional practice administered by a large and special bureaucracy, playing a substantial role in authorizing the use of coercive police force, leading to a harsh sanctioning regime linked, at least in part, with core wrongs and notions of personal responsibility. Although none of these features is exclusive to criminal law, (...) their interaction leads to modes of behavior that set it apart from other institutions. The paper argues that putting attention on the effects of this interaction provides us with powerful tools to both understand and asses the value and problems of criminal law. (shrink)

Este escrito se propone pensar el papel de las imágenes y de la «invención» en el proyecto de la Unidad Popular. Si la inventiva, como forma de entender el trabajo colectivo, surge en distintas iniciativas de la UP que buscan mejorar las condiciones de vida de los trabajadores, a la vez que intentando legitimar el proyecto socialista al consolidar sus logros y su capacidad de funcionar como alternativa a los modelos de producción capitalista, la invención en tanto «combinación original de (...) rayos imitativos» (Tarde) opera en paralelo como una forma de asociatividad inédita promovida por el proyecto popular y, en esa medida, las trayectorias y relaciones que suscita son menos lineales que lo que las imágenes, entendidas como mecanismo de captura y fijación representacional, permiten entender. Es por esto que el artículo se propone pensar otros modos de narrar la Unidad Popular en los que las imágenes funcionen como máquinas o «agenciamientos maquínicos» (Guattari), esto es, como registros de lo múltiple que emergen dentro de una formación social compleja y en constante mutación. Para ello, el texto conecta dos hitos de la UP que inscriben la invención como un eje articulador de la redefinición de lo social: la colección «Nosotros los chilenos», de Quimantú (1971-1973), y el edificio UNCTAD III (1971-1972). (shrink)

Jonathan Schaffer has provided three putative counterexamples to the transitivity of grounding, and has argued that a contrastive treatment of grounding is able to provide a resolution to them, which in turn provides some motivation for accepting such a treatment. In this article, I argue that one of these cases can easily be turned into a putative counterexample to a principle which Schaffer calls differential transitivity. Since Schaffer's proposed resolution rests on this principle, this presents a dilemma for the contrastivist: (...) either he dismisses the third case, which weakens the motivation for accepting his treatment of grounding, or else he accepts it, in which case he is faced with a counterexample to a principle that his proposed resolution to the original cases depends on. In the remainder of the article, I argue that the prima facie most promising strategy the contrastivist could take, which is to place some restriction on which contrastive facts are admissible so as to rule out the purported counterexample to differential transitivity, faces some important difficulties. Although these difficulties are not insurmountable, they do pose a substantial challenge for the contrastivist. (shrink)

Kris McDaniel has recently defended a criterion for being an ontological pluralist that classifies the quantifier variantist as one. In this paper, I argue that this is a mistake. There is an important difference between the two views, which is sometimes obscured by a common view in the metaphysics of fundamentality. According to the simple analysis, a language is ideal—it allows for a maximally metaphysically perspicuous description of reality—just in case all its primitives are perfectly natural. I argue that this (...) analysis struggles to distinguish quantifier variance from ontological pluralism, and then I discuss various accounts that can do better. I then propose a criterion for being an ontological pluralist that does not misclassify the quantifier variantist. Finally, I discuss some additional advantages of my proposal. (shrink)

Philippe Huneman has recently questioned the widespread application of mechanistic models of scientific explanation based on the existence of structural explanations, i.e. explanations that account for the phenomenon to be explained in virtue of the mathematical properties of the system where the phenomenon obtains, rather than in terms of the mechanisms that causally produce the phenomenon. Structural explanations are very diverse, including cases like explanations in terms of bowtie structures, in terms of the topological properties of the system, or in (...) terms of equilibrium. The role of mathematics in bowtie structured systems and in topologically constrained systems has recently been examined in different papers. However, the specific role that mathematical properties play in equilibrium explanations requires further examination, as different authors defend different interpretations, some of them closer to the new-mechanistic approach than to the structural model advocated by Huneman. In this paper, we cover this gap by investigating the explanatory role that mathematics play in Blaser and Kirschner’s nested equilibrium model of the stability of persistent long-term human-microbe associations. We argue that their model is explanatory because: i) it provides a mathematical structure in the form of a set of differential equations that together satisfy an ESS; ii) that the nested nature of the ESSs makes the explanation of host-microbe persistent associations robust to any perturbation; iii) that this is so because the properties of the ESS directly mirror the properties of the biological system in a non-causal way. The combination of these three theses make equilibrium explanations look more similar to structural explanations than to causal-mechanistic explanation. (shrink)

El consumo de energía y el crecimiento económico han llevado a la degradación del medio ambiente. Las centrales eléctricas son una de las principales fuentes de contaminación. Existe una necesidad de utilizar energías renovables para reducir el impacto ambiental. Sin embargo, en los países en desarrollo, la falta de recursos económicos limita la adopción de energías limpias. Las energías limpias, como la solar, eólica, hidroeléctrica y geotérmica, son fuentes sostenibles de energía. La energía hidroeléctrica puede ser controvertida debido a sus (...) impactos ambientales y sociales. La biomasa y el biogás también son fuentes de energía renovable. La eficiencia energética es otra área importante para reducir la dependencia de los recursos no renovables. El artículo discute la importancia de las energías limpias y el desarrollo sostenible en el Perú. Se menciona el potencial de la energía de las olas marinas, el bioetanol y el biodiesel como fuentes de energía renovable. También se abordan los impactos ambientales de los "negocios sucios" y las implicaciones socioeconómicas de las energías limpias. Se discuten los conflictos de interés y la regulación normativa en el país, así como las perspectivas futuras y la necesidad de un desarrollo energético estable y sostenible. Palabras clave: Energías limpias, negocios sucios, impacto ambiental, sostenibilidad. (shrink)

En este trabajo ofrecemos un panorama al estudio de los sesgos. El creciente interés en ellos durante las últimas décadas radica en que estudiarlos implica hablar de cómo los seres humanos razonamos y emitimos juicios, e igualmente sobre los mecanismos y procesos que subyacen a tales capacidades, esto incluye entender cuándo y por qué frecuentemente nos equivocamos, como lo indica buena parte de la literatura en psicología cognitiva del razonamiento. Dada la existencia de los sesgos, han surgido posturas pesimistas que (...) sostienen que los sesgos muestran que los humanos son irracionales. Frente a estas, la literatura reciente ofrece visiones mas optimistas, y aduce que los sesgos pueden “desaparecer” si se tienen en consideración diferentes aspectos de tipo evolutivo. Otra postura es aquella que sostienen que la supervivencia humana no yace en la inteligencia individual sino en la colectiva. Es decir, que podemos dejar de confiar exclusivamente en el contenido de nuestra mente y en su lugar resolver los problemas colectivamente, gracias a la división de las tareas cognitivas. Para organizar la exposición dividimos el trabajo en tres enigmas de los sesgos cognitivos. El primero consiste en una discusión sobre el origen de los sesgos. El segundo concierne a su clasificación e inventarios. El tercer enigma versa sobre la unidad de análisis de la cognición humana, a saber, inteligencia individual versus inteligencia colectiva. Con estos enigmas queremos poner de manifiesto el abanico de discusiones que giran alrededor de los sesgos, sus problemas, así como la creciente fascinación por entenderlos. Estudiar los sesgos abona a la comprensión de cómo razonamos o pensamos, y esto nos ayuda a mejorar nuestro pensamiento crítico. (shrink)

According to the cohabitation account, all the persons that result from a fission event cohabit the same body prior to fission. This article concerns a problem for this account. Suppose Manuel and Jimena are suffering from an equally painful migraine. Unlike Jimena, however, Manuel will undergo fission. Assuming you have a spare painkiller, whom should you give it to? Intuitively, you have no more reason to give it to one or the other. The problem is that the cohabitation account suggests (...) otherwise. According to the account, there are two persons cohabiting Manuel’s body, in which case you should arguably give them the pill, since doing so alleviates the pain of more beings. One response argues that the two persons cohabiting Manuel’s body share one pain. Thus, giving them the pill alleviates no more pain than giving it to Jimena, and therefore you have no more reason to do one or the other. The goal of this article is to show that this response fails. (shrink)

Lewis has objected to Armstrong's notion of a structural universal on the grounds that it violates the Principle of Uniqueness of Composition (PUC), which says that given some parts, there is only one whole that they compose. This paper reviews Armstrong's case for structural universals, and then attempts to reconcile structural universals with PUC by arguing for the existence of arrangement universals. The latter are not only a key to defending structural universals against Lewis' objection, but are in fact essential (...) to Armstrong's conception of structural universals in general. Three objections to my proposal are deflected, and two alternative proposals are shown to be inferior to it. (shrink)