Predictable polarization is everywhere: we can often predict how people’s opinions, including our own, will shift over time. Extant theories either neglect the fact that we can predict our own polarization, or explain it through irrational mechanisms. They needn’t. Empirical studies suggest that polarization is predictable when evidence is ambiguous, that is, when the rational response is not obvious. I show how Bayesians should model such ambiguity and then prove that—assuming rational updates are those which obey the value of evidence—ambiguity (...) is necessary and sufficient for the rationality of predictable polarization. The main theoretical result is that there can be a series of such updates, each of which is individually expected to make you more accurate, but which together will predictably polarize you. Polarization results from asymmetric increases in accuracy. This mechanism is not only theoretically possible, but empirically plausible. I argue that cognitive search—searching a cognitively accessible space for a particular item—often yields asymmetrically ambiguous evidence, I present an experiment supporting its polarizing effects, and I use simulations to show how it can explain two of the core causes of polarization: confirmation bias and the group polarization effect. (shrink)

Polarization is a topic of intense interest among social scientists, but there is significant disagreement regarding the character of the phenomenon and little understanding of underlying mechanics. A first problem, we argue, is that polarization appears in the literature as not one concept but many. In the first part of the article, we distinguish nine phenomena that may be considered polarization, with suggestions of appropriate measures for each. In the second part of the article, we apply this analysis to evaluate (...) the types of polarization generated by the three major families of computational models proposing specific mechanisms of opinion polarization. (shrink)

Recent research on thick terms like “rude” and “friendly” has revealed a polarity effect, according to which the evaluative content of positive thick terms like “friendly” and “courageous” can be more easily canceled than the evaluative content of negative terms like “rude” and “selfish”. In this paper, we study the polarity effect in greater detail. We first demonstrate that the polarity effect is insensitive to manipulations of embeddings (Study 1). Second, we show that the effect occurs not (...) only for thick terms but also for thin terms such as “good” or “bad” (Study 2). We conclude that the polarity effect indicates a pervasive asymmetry between positive and negative evaluative terms. (shrink)

In recent epistemology, belief polarization is generally defined as a process by which a disagreement on a single proposition becomes more extreme over time. Outside of the philosophical literature, however, ‘polarization’ is often used for a different epistemic phenomenon, namely the process by which people’s beliefs on unrelated topics become increasingly correlated over time. This paper argues that the latter type of polarization, here labeled interthematic polarization, is often rational from each individual’s point of view. This suggests that belief polarization (...) is not necessarily a failure of individual rationality, but instead a failure of the social structures within which we live our epistemic lives. (shrink)

Polarization is a topic of intense interest among social scientists, but there is significant disagreement regarding the character of the phenomenon and little understanding of underlying mechanics. A first problem, we argue, is that polarization appears in the literature as not one concept but many. In the first part of the article, we distinguish nine phenomena that may be considered polarization, with suggestions of appropriate measures for each. In the second part of the article, we apply this analysis to evaluate (...) the types of polarization generated by the three major families of computational models proposing specific mechanisms of opinion polarization. (shrink)

An electronic poster from "Polarity from Different Perspectives," New York University, 2005. The authors present an experiment that investigated to what extent six negative polarity items (slept a wink, in ages, ever, much, at all, and yet) are licensed by 9 potential licensers.

What is the communicative value of negative polarity? That is, why do so many languages maintain a stock of special indefinites that occur only in a proper subset of the contexts in which ordinary indefinites can appear? Previous answers include: marking the validity of downward inferences; marking the invalidity of veridical inferences; or triggering strengthening implications. My starting point for exploring a new answer is the fact that an NPI must always take narrow scope with respect to its licensing (...) context. In contrast, ordinary indefinites are notorious for taking wide scope. So whatever other functions NPIs may have, they at least serve as an utterly reliable signal that an indefinite is taking narrow scope. As also proposed in recent work of Kusumoto and Tancredi, I will show that NPIs are only licensed in contexts in which the wide scope construal of an indefinite fails to entail the narrow scope. In other words, weak NPIs occur only in contexts in which taking narrow scope matters for interpretation. Thus one part of the explanation for the ubiquity and robust stability of negative polarity is that it signals scope relations. (shrink)

False polarization (FP) is an interpersonal bias on judgement, the effect of which is to lead people in contexts of disagreement to overestimate the differences between their respective views. I propose to treat FP as a problem of applied social epistemology—a barrier to reliable belief-formation in certain social domains—and to ask how best one may debias for FP. This inquiry leads more generally into questions about effective debiasing strategies; on this front, considerable empirical evidence suggests that intuitively attractive strategies for (...) debiasing are not very effective, while more effective strategies are neither intuitive nor likely to be easily implemented. The supports for more effective debiasing seem either to be inherently social and cooperative, or at least to presuppose social efforts to create physical or decision-making infrastructure for mitigating bias. The upshot, I argue, is that becoming a less biased epistemic agent is a thoroughly socialized project. (shrink)

"The book's major parts, one on polarity and the other on analogy, introduce the reader to the patterns of thinking that are fundamental not only to Greek philosophy but also to classical civilization as a whole. As a leading classicist in his own right, Lloyd is an impeccable guide. His sophistication in adducing anthropological parallels to Greek models of polarity and analogy broadens his perspective, making him a forerunner in the study of what we are now used to (...) calling semiotics. A striking example of Lloyd's approach is his re-examination of the dichotomy of Olympian and chthonian gods in ancient Greek world view, which surpasses the reductionist and pseudo-historical models of sky-gods and earth-goddesses that are still commonly invoked to account for polarities in Greek pantheon. "In the second part, dealing with analogy, three crucial metaphorical models for the universe turn out to be basis for a dazzlingly wide variety of scientific and philosophical perspectives. Each model is tested in the whole spectrum of Greek artistic, philosophical and scientific thought. This work is a treasure-house of insights for experts and non experts alike." --Gregory Nagy, Harvard University. (shrink)

Contemporary societies are often “polarized”, in the sense that sub-groups within these societies hold stably opposing beliefs, even when there is a fact of the matter. Extant models of polarization do not capture the idea that some beliefs are true and others false. Here we present a model, based on the network epistemology framework of Bala and Goyal, 784–811 1998), in which polarization emerges even though agents gather evidence about their beliefs, and true belief yields a pay-off advantage. As we (...) discuss, these results are especially relevant to polarization in scientific communities, for these reasons. The key mechanism that generates polarization involves treating evidence generated by other agents as uncertain when their beliefs are relatively different from one’s own. (shrink)

When public opinion gets polarized, the population’s beliefs can experience two different changes: they can become more extreme in their contents or they can be held with greater confidence. These two possibilities point to two different understandings of the rupture that characterizes political polarization: extremism and radicalism. In this article, I show that from the close examination of the best available evidence regarding how we get polarized, it follows that the pernicious type of political polarization has more to do with (...) radicalism than with extremism. Reinforcing the confidence in the core beliefs of the group we identify with makes our beliefs immune to the reasons coming from the other political side. Finally, I also suggest that the rise of political polarization is not necessarily the result of an irrational process. (shrink)

This paper uses the distribution and interpretation of antonymous adjectives in comparative constructions as an empirical basis to argue that abstract representations of measurement, or ‘degrees’, must be modeled as intervals on a scale, rather than as points, as commonly assumed. I begin by demonstrating that the facts in this domain must be accounted for in terms of the interaction of the semantics of adjectival polarity and the semantics of the comparative, rather than principles governing the (overt) expression of (...) particular types of adjectives in comparatives. I then show that a principled account of the full range of data under consideration can be constructed within a model in which degrees are formalized as intervals on a scale and adjectival polarity is characterized in terms of two structurally distinct and complementary sorts of `positive' and `negative' degrees. (shrink)

Group polarization—roughly, the tendency of groups to incline towards more extreme positions than initially held by their individual members— has been rigorously studied by social psychol- ogists, though in a way that has overlooked important philosophical questions about this phenomenon which remain unexplored. Two such salient questions are metaphysical and epistemological, respectively. From a metaphysical point of view, can group polarization, understood as an epistemic feature of a group, be reduced to epistemic features of its individual members? Relatedly, from an (...) epistemological point of view, is group polarization best understood as a kind of cognitive bias or rather in terms of intellectual vice? This book taxonomizes this possibility space by comparing four models which combine potential answers to the metaphysical and epistemological questions. The models we consider are: group polarization as a collective bias, a summation of individual epistemic vices; a summation of individual biases; and a collective epistemic vice. We defend a collective vice model of group polarization over the competing alternatives. (shrink)

Positive polarity items (PPIs) are generally thought to have the boring property that they cannot scope below negation. The starting point of the paper is the observation that their distribution is significantly more complex; specifically, someone/something-type PPIs share properties with negative polarity items (NPIs). First, these PPIs are disallowed in the same environments that license yet type NPIs; second, adding any NPI-licenser rescues the illegitimate constellation. This leads to the conclusion that these PPIs have the combined properties of (...) yet-type and ever-type NPIs: what appears to be a prohibition is nothing but “halfway licensing”. The paper goes on to propose a unification of the analyses of rescuable PPIs, NPIs, and negative concord, and questions the grounding of polarity sensitivity in the scalar or the referential semantics of the items involved. (shrink)

Polarity Items are linguistic expressions known for being a ‘lexically controlled’ phenomenon. In this paper we show how their behavior can be implemented in a deductive system. Further- more, we point out some possible directions to recast the deductive solution into a Tree Ad- joining Grammar system. In particular, we suggest to compare the proof system developed for Multimodal Categorial Grammar (Moot & Puite, 1999) with the Partial Proof Trees proposed in (Joshi & Kulick, 1997).

Many scholars of early China agree that the fourth century bce witnessed a surge in intellectual interest in concepts that have been dubbed the self, “subjectivity,” the private realm, and the body. As such a sphere came into greater focus in intellectual circles, so did a new discourse that evaluated what it meant to benefit or deprive the self and its related parts. The famous statement purportedly by Yang Zhu 楊朱 (or Yangzi 楊子) that claims he was not willing to (...) pluck out a single hair in order to benefit the world reminds us of such a discourse.2 Around the same time, there also emerged discussions that polarized various ideas of self and the private sphere (si 私), on the one hand, ver- sus the state and the public sphere (gong 公), on the other, especially in circles that concerned themselves with public policy and statecraft, but also more generally. These discussions formed a forceful counterpoint to the discourses involving human subjectivity and the body. Indeed, their open dislike of the influence of private, individual, and personal realms in politics strongly suggests that the statecraft writers were re- acting to and in dialog with those intellectuals who engaged discussion of subjectivity, the self, and its agencies. (shrink)

In this paper we present the results of a simulation study of credence developments in groups of communicating Bayesian agents, as they update their beliefs about a given proposition p. Based on the empirical literature, one would assume that these groups of rational agents would converge on a view over time, or at least that they would not polarize. This paper presents and discusses surprising evidence that this is not true. Our simulation study shows that these groups of Bayesian agents (...) show group polarization behavior under a broad range of circumstances. This is, we think, an unexpected result, that raises deeper questions about whether the kind of polarization in question is irrational. If one accepts Bayesian agency as the hallmark of epistemic rationality, then one should infer that the polarization we find is also rational. On the other hand, if we are inclined to think that there is something epistemically irrational about group polarization, then something must be off in the model employed in our simulation study. We discuss several possible interfering factors, including how epistemic trust is defined in the model. Ultimately, we propose that the notion of Bayesian agency is missing something in general, namely the ability to respond to higher-order evidence. (shrink)

ABSTRACT This article distinguishes nine senses of polarization and provides formal measures for each one to refine the methodology used to describe polarization in distributions of attitudes. Each distinct concept is explained through a definition, formal measures, examples, and references. We then apply these measures to GSS data regarding political views, opinions on abortion, and religiosity—topics described as revealing social polarization. Previous breakdowns of polarization include domain-specific assumptions and focus on a subset of the distribution’s features. This has conflated multiple, (...) independent features of attitude distributions. The current work aims to extract the distinct senses of polarization and demonstrate that by becoming clearer on these distinctions we can better focus our efforts on substantive issues in social phenomena. (shrink)

A popular claim is that social media is a cause of contemporary high levels of political polarization. In this paper, I consider three of the most common kinds of arguments for the thesis. One type lays out a narrative of causes, tracing the causal steps between logging on to social media and later becoming more polarized. Another type uses computer modeling to show how polarized effects can arise from systems that are analogous to use of social media. The final type (...) considers straightforward experimental evidence for the polarizing effect. I reject each of these arguments and explain why they are unconvincing. (shrink)

The present paper is an attempt at the investigation of the nature of polarity contrast in natural languages. Truth conditions for natural language sentences are incomplete unless they include a proper definition of the conditions under which they are false. It is argued that the tertium non datur principle of classical bivalent logical systems is empirically invalid for natural languages: falsity cannot be equated with non-truth. Lacking a direct intuition about the conditions under which a sentence is false, we (...) need an independent foundation of the concept of falsity. The solution I offer is a definition of falsity in terms of the truth of a syntactic negation of the sentence. A definition of syntactic negation is proposed for English. (shrink)

Public health care interventions—regarding vaccination, obesity, and HIV, for example—standardly take the form of information dissemination across a community. But information networks can vary importantly between different ethnic communities, as can levels of trust in information from different sources. We use data from the Greater Pittsburgh Random Household Health Survey to construct models of information networks for White and Black communities--models which reflect the degree of information contact between individuals, with degrees of trust in information from various sources correlated with (...) positions in that social network. With simple assumptions regarding belief change and social reinforcement, we use those modeled networks to build dynamic agent-based models of how information can be expected to flow and how beliefs can be expected to change across each community. With contrasting information from governmental and religious sources, the results show importantly different dynamic patterns of belief polarization within the two communities. (shrink)

A population can be ideologically or affectively polarized. Ideological polarization relates to people’s political beliefs, while affective polarization deals with people’s feelings toward the ingroup and the outgroup. Both types of mental states, beliefs and feelings, are typically measured through direct self-report surveys. One philosophical assumption underlying this way of measuring polarization is a concrete version of the first-person authority thesis: the speaker’s sincerity guarantees the truth of their mental self-ascriptions. Based on various empirical studies, the first part of this (...) paper argues that we are particularly bad at spotting our own mental states regard­ing political issues. This, in turn, raises doubts about the accuracy of direct self-report surveys in measuring polarization. In the second part, I introduce Michael Lynch’s notion of political meaning to argue that traditional surveys can still provide valuable information for detecting polarization. However, I suggest that this information pertains not to participants’ beliefs and feelings, but rather to their level of commitment to the core beliefs of the political groups they identify with, which is a relevant aspect of pernicious polarization. (shrink)

Public discussions of political and social issues are often characterized by deep and persistent polarization. In social psychology, it’s standard to treat belief polarization as the product of epistemic irrationality. In contrast, we argue that the persistent disagreement that grounds political and social polarization can be produced by epistemically rational agents, when those agents have limited cognitive resources. Using an agent-based model of group deliberation, we show that groups of deliberating agents using coherence-based strategies for managing their limited resources tend (...) to polarize into different subgroups. We argue that using that strategy is epistemically rational for limited agents. So even though group polarization looks like it must be the product of human irrationality, polarization can be the result of fully rational deliberation with natural human limitations. (shrink)

Belief polarization occurs when subjects who disagree about some matter of fact are exposed to a mixed body of evidence that bears on that dispute. While we might expect mutual exposure to common evidence to mitigate disagreement, since the evidence available to subjects comes to consist increasingly of items they have in common, this is not what happens. The subjects’ initial disagreement becomes more pronounced because each person increases confidence in her antecedent belief. Kelly aims to identify the mechanisms that (...) underlie this phenomenon and assess whether these processes undermine the justification of polarized beliefs. He concludes that given evidentialism, justification is not undermined by the polarizing mechanisms. I take on board Kelly’s description of the polarizing mechanisms, but challenge his conclusion. I argue that on plausible versions of evidentialism, the beliefs that result from these routes to polarization are not justified. (shrink)

Polarization simplifies and deforms language, ideas, and people and reduces social life into an oppositional binary based on harmful “us versus them” narratives. What can we do to bring about a transformation away from polarity to peace? What are the polarities obscuring the path to peace? Is it a question of belief versus belief? Does it make sense to appeal to reason, discourse, and compromise in a polarized climate? What is the difference between harmful and helpful polarities? In the (...) pursuit of peace and justice, the authors in this volume answer these and other questions relating to polarity and politics. (shrink)

For two ideally rational agents, does learning a finite amount of shared evidence necessitate agreement? No. But does it at least guard against belief polarization, the case in which their opinions get further apart? No. OK, but are rational agents guaranteed to avoid polarization if they have access to an infinite, increasing stream of shared evidence? No.

This paper gives an account of the differences between polar and alternative questions, as well as an account of the division of labor between compositional semantics and pragmatics in interpreting these types of questions. Alternative questions involve a strong exhaustivity presupposition for the mentioned alternatives. We derive this compositionally from the meaning of the final falling tone and its interaction with the pragmatics of questioning in discourse. Alternative questions are exhaustive in two ways: they exhaust the space of epistemic possibilities, (...) as well as the space of discourse possibilities (the Question Under Discussion). In contrast, we propose that polar questions are the opposite: they present just one alternative that is necessarily non-exhaustive. The account explains a range of response patterns to alternative and polar questions, as well as differences and similarities between the two types of questions. (shrink)

(OPEN ACCESS) This paper establishes moral duties for intermediaries of political advertising in election campaigns. First, I argue for a collective duty to maintain the democratic quality of elections which entails a duty to contain some forms of political polarization. Second, I show that the focus of campaign ethics on candidates, parties and voters—ignoring the mediators of campaigns—yields mistaken conclusions about how the burdens of the latter collective duty should be distributed. Third, I show why it is fair to require (...) intermediaries to contribute to fulfilling this duty: they have an ultimate filtering position in the campaign communication process and typically benefit from political advertising and polarization. Finally, I argue that a transparency-based ethics of campaign advertising cannot properly accommodate a concern with objectionable polarization. By contrast, I outline the polarization-containing implications of my account, including a prohibition on online targeted advertising, and intermediaries’ duties to block hateful political advertising. (shrink)

We study the effective and proof-theoretic content of the polarized Ramsey’s theorem, a variant of Ramsey’s theorem obtained by relaxing the definition of homogeneous set. Our investigation yields a new characterization of Ramsey’s theorem in all exponents, and produces several combinatorial principles which, modulo bounding for ${\Sigma^0_2}$ formulas, lie (possibly not strictly) between Ramsey’s theorem for pairs and the stable Ramsey’s theorem for pairs.

Trust in vaccination is eroding, and attitudes about vaccination have become more polarized. This is an observational study of Twitter analyzing the impact that COVID-19 had on vaccine discourse. We identify the actors, the language they use, how their language changed, and what can explain this change. First, we find that authors cluster into several large, interpretable groups, and that the discourse was greatly affected by American partisan politics. Over the course of our study, both Republicans and Democrats entered the (...) vaccine conversation in large numbers, forming coalitions with Antivaxxers and public health organizations, respectively. After the pandemic was officially declared, the interactions between these groups increased. Second, we show that the moral and non-moral language used by the various communities converged in interesting and informative ways. Finally, vector autoregression analysis indicates that differential responses to public health measures are likely part of what drove this convergence. Taken together, our results suggest that polarization around vaccination discourse in the context of COVID-19 was ultimately driven by a trust-first dynamic of political engagement. (shrink)

The relatively simple central nervous system (CNS) of the Drosophila embryo provides a useful model system for investigating the mechanisms that generate and pattern complex nervous systems. Central to the generation of different types of neurons by precursor neuroblasts is the initial specification of neuroblast identity and the Drosophila segment polarity genes, genes that specify regions within a segment or repeating unit of the Drosophila embryo, have emerged recently as significant players in this process. During neurogenesis the segment (...) class='Hi'>polarity genes are expressed in the neuroectodermal cells from which neuroblasts delaminate and they continue to be expressed in neuroblasts and their progeny. Loss-of-function mutations in these genes lead to a failure in the formation of neuroblasts and/or specification of neuroblast identity. Results from several recent studies suggest that regulatory interactions between segment polarity genes during neurogenesis lead to an increase in the number of neuroblasts and specification of different identities to neuroblasts within a population of cells. BioEssays 21:472–485, 1999. © 1999 John Wiley & Sons, Inc. (shrink)

Belief polarization is widely seen to threaten havoc on our shared political lives. It is often assumed that BP is the product of epistemically irrational behaviors at the individual level. After distinguishing between BP as it occurs in intra-group and inter-group settings, this paper argues that neither process necessarily reflects individual epistemic irrationality. It is true that these processes can work in tandem to produce so-called “echo chambers.” But while echo chambers are often problematic from the point of view of (...) collective rationality, it doesn't follow that individuals are doing anything wrong, epistemically speaking, in seeking them out. In non-ideal socio-epistemic contexts, echo chamber construction might provide one's best defense against systematic misinformation and deception. (shrink)

The minimal weakening \ of Belnap-Dunn logic under the polarity semantics for negation as a modal operator is formulated as a sequent system which is characterized by the class of all birelational frames. Some extensions of \ with additional sequents as axioms are introduced. In particular, all three modal negation logics characterized by a frame with a single state are formalized as extensions of \. These logics have the finite model property and they are decidable.

An approximate model of a spacetime foam is presented. It is supposed that in the spacetime foam each quantum handle is like to an electric dipole and therefore the spacetime foam is similar to a dielectric. If we neglect of linear sizes of the quantum handle then it can be described with an operator containing a Grassman number and either a scalar or a spinor field. For both fields the Lagrangian is presented. For the scalar field it is the dilaton (...) gravity + electrodynamics and the dilaton field is a dielectric permeability. The spherically symmetric solution in this case give us the screening of a bare electric charge surrounded by a polarized spacetime foam and the energy of the electric field becomes finite one. In the case of the spinor field the spherically symmetric solution give us a ball of the polarized spacetime foam filled with the confined electric field. It is shown that the full energy of the electric field in the ball can be very big. (shrink)

Notch is a mechanosensitive receptor that requires direct cell–cell contact for its activation. Both the strength and the range of notch signaling depend on the size and geometry of the contact sites between cells. These properties of cell–cell contacts in turn depend on cell shape and polarity. At the molecular level, the E3 ubiquitin ligase Neuralized links receptor activation with epithelial cell remodeling. Neur regulates the endocytosis of the Notch ligand Delta, hence Notch activation. It also targets the apical (...) polarity protein Stardust to promote the endocytosis of the Crumbs complex, thereby contributing to epithelium remodeling. Here, we review the interplay between Notch signaling and cell polarity and discuss the possible significance of linking Notch signaling with epithelial cell polarity via a common regulator. Notch receptor activation depends on direct cell–cell contacts that in turn depends on cell shape and cellular polarity. The size and geometry of cell–cell contacts have an impact on the strength and range of signaling. The E3 ubiquitin ligase Neuralized regulates the endocytosis and signaling activity of Delta. The activity of Neuralized is tightly regulated during development. Neuralized also modulates epithelial cell polarity by targeting the apical polarity protein Stardust and by promoting the endocytosis of Crumbs. Thus, the cell-specific expression of Neuralized couples Notch receptor activation with cell polarity regulation in epithelia. (shrink)

Notch is a mechanosensitive receptor that requires direct cell–cell contact for its activation. Both the strength and the range of notch signaling depend on the size and geometry of the contact sites between cells. These properties of cell–cell contacts in turn depend on cell shape and polarity. At the molecular level, the E3 ubiquitin ligase Neuralized links receptor activation with epithelial cell remodeling. Neur regulates the endocytosis of the Notch ligand Delta, hence Notch activation. It also targets the apical (...) polarity protein Stardust to promote the endocytosis of the Crumbs complex, thereby contributing to epithelium remodeling. Here, we review the interplay between Notch signaling and cell polarity and discuss the possible significance of linking Notch signaling with epithelial cell polarity via a common regulator. Notch receptor activation depends on direct cell–cell contacts that in turn depends on cell shape and cellular polarity. The size and geometry of cell–cell contacts have an impact on the strength and range of signaling. The E3 ubiquitin ligase Neuralized regulates the endocytosis and signaling activity of Delta. The activity of Neuralized is tightly regulated during development. Neuralized also modulates epithelial cell polarity by targeting the apical polarity protein Stardust and by promoting the endocytosis of Crumbs. Thus, the cell-specific expression of Neuralized couples Notch receptor activation with cell polarity regulation in epithelia. (shrink)

We dub the kyaa in (2a) polar kyaa, which we distinguish from the homophonous thematic kyaa ‘what’. in (3). In (3), kyaa is the theme argument of the verb diyaa ‘gave’. The same has been argued for the scope marking construction, at least under the indirect dependency approach (Dayal 1994 among others). The preverbal position has been argued to be the unmarked position for wh-words in Hindi-Urdu (Kidwai 2000, among others).

Americans today don't trust each other and their institutions as much as they once did, fueling destructive ideological conflicts and hardened partisanship. In Trust in a Polarized Age, political philosopher Kevin Vallier argues that to build social trust and reduce polarization, we must strengthen liberal democratic institutions--high-quality governance, procedural fairness, markets, social welfare programs, freedom of association, and democracy. These institutions not only create trust, they do so justly, by recognizing and respecting our basic rights.

Planar cell polarity, the polarization of cells within the plane of the epithelium, orthogonal to the apical‐basal axis, is essential for a growing list of developmental events, and – over the last 15 years – has evolved from a little‐studied curiosity in Drosophila to the subject of a substantial research enterprise. In that time, it has been recognized that two molecular systems are responsible for polarization of most tissues: Both the “core” Frizzled system and the “global” Fat/Dachsous/Four‐jointed system produce (...) molecular asymmetry within cells, and contribute to morphological polarization. In this review, we discuss recent findings on the molecular mechanism that links “global” directional signals with local coordinated polarity. (shrink)

Negative polarity is one of the more elusive aspects of linguistics and a subject which has been gaining in importance in recent years. Written from within the well-defined theoretical framework of Generalized Quantifiers, the three main areas considered in this study are collocations, polarity items and multiple negations. In this mature piece of research, van der Wouden takes into account, not only semantic and syntactic considerations, but also to a large extent, pragmatic ones illustrating a wide array of (...) linguistic approaches. (shrink)

The motion of geographic poles, predicted by Euler, was discovered at the end of the 1880s, mainly by German and American astronomers. However, French astronomers were strongly reluctant to accept the reality of this phenomenon. Indeed, all observations at the Observatoire de Paris converged toward non-detection of the polar motion. Science, as most fields of public life, was extremely centralized in France, and the Observatoire de Paris was still living on past glory gained in the field of classical astronomy. However, (...) the directors who succeeded Urbain Le Verrier were doubtful about the accuracy of the observation in such an urban observatory, and were pushing for the construction of an observatory outside the city. At the same time, just after the French defeat of 1871, a wide decentralization of the universities started, and a few big regional cities were selected to host new observatories. In this paper we show how it is in one of these new observatories, in Lyon, that the polar motion was first observed in France, and how this was immediately recognized internationally. Although the weight of French Jacobinism kept the new observatories at an embryonic stage for many decades, this contribution to an internationally discussed problem shows how enthusiastically and efficiently work was carried out in the early years of French provincial observatories.Keywords: Polar motion; Observatoire de Lyon; François Gonnessiat; French decentralization. (shrink)

Resumen: El objetivo de este trabajo es defender la idea de polarización como impermeabilidad, un sentido de polarización que se ha pasado por alto en la literatura sobre polarización política. Según este sentido de polarización, una persona o un grupo se polariza en la medida en que cada vez sea más impermeable a las ideas o razones ajenas. De esta manera, y en contra de la idea en la que se basan los sentidos de polarización disponibles en la literatura hasta (...) el momento, una población o un grupo puede polarizarse si no ha habido ningún movimiento del centro hacia los extremos del espectro ideológico. Asimismo, se defenderá que entender la polarización en este nuevo sentido ofrece ventajas por varias razones: i) la polarización como impermeabilidad es un sentido de polarización más acorde con algunos de los fenómenos que son relevantes para entender las sociedades democráticas actuales: la economía de la atención, la personalización de la información o las cámaras de eco; ii) entender la polarización de manera estándar, es decir, como un desplazamiento del centro hacia los extremos del espectro ideológico, conlleva ciertos problemas.: The aim of this paper is to defend the idea of polarization as impermeability, a sense of polarization that has been overlooked in the debate on political polarization. According to this sense of polarization, a person or group is polarized to the extent that it is impervious to the ideas or reasons of others. In this way, and contrary to the idea on which the senses of polarisation available in literature so far are based, a person or group may be polarised if there has been no movement from the centre to the extremes of the ideological spectrum. Likewise, it will be defended that understanding polarization in this new sense offers advantages for several reasons: i) polarization as impermeability is a sense of polarization more in line with some of the phenomena that are relevant to understanding today’s democratic societies: the economy of attention, the personalization of information or echo chambers; ii) understanding polarization in a standard way, that is, as a shift from the centre towards the ends of the ideological spectrum, entails certain problems. (shrink)

Modern logicians have sought to unlock the modal secrets of Aristotle's Syllogistic by assuming a version of essentialism and treating it as a primitive within the semantics. These attempts ultimately distort Aristotle's ontology. None of these approaches make full use of tests found throughout Aristotle's corpus and ancient Greek philosophy. I base a system on Aristotle's tests for things that can never combine (polarity) and things that can never separate (inseparability). The resulting system not only reproduces Aristotle's recorded results (...) for the apodictic syllogistic in the Prior Analytics but it also generates rather than assumes Aristotle's distinctions among 'necessary', 'essential' and 'accidental'. By developing a system around tests that are in Aristotle and basic to ancient Greek philosophy, the system is linked to a history of practices, providing a platform for future work on the origins of logic. (shrink)