In this paper we show the adequacy of tense logic with unary operators for dealing with finite trees. We prove that models on finite trees can be characterized by tense formulas, and describe an effective method to find an axiomatization of the theory of a given finite tree in tense logic. The strength of the characterization is shown by proving that adding the binary operators "Until" and "Since" to the language does not result in a better description than that given (...) by unary tense logic; although the greater expressive power of "Until" and "Since" can be exploited by using the semantics of e-frames instead of traditional Kripke semantics. (shrink)

The aim of this paper is to give, using the Kripke semantics for intuitionism, a representation of finitely generated free Heyting algebras. By means of the representation we determine in a constructive way some set of "special elements" of such algebras. Furthermore, we show that many algebraic properties which are satisfied by the free algebra on one generator are not satisfied by free algebras on more than one generator.

A new concept of model for the US-tense logic is introduced, in which ternary relations of betweenness are adjoined to the usual early-later relation. The class of these new models, which contains the class of Kripke models, satisfies, contrary to that, the Distinguishable Model Theorem, in the sense that each model is equivalent to a model in which no two points verify exactly the same formulas.

The semantics of e-models for tense logics with binary operators for `until' and `since' (US-logics) was introduced by Bellissima and Bucalo in 1995. In this paper we show the adequacy of these semantics by proving a general Henkin-style completeness theorem. Moreover, we show that for these semantics there holds a Stone-like duality theorem with the algebraic structures that naturally arise from US-logics.

We consider the problem of finding, in the ambit of modal logic, a minimal characterization for finite Kripke frames, i.e., a formula which, given a frame, axiomatizes its theory employing the lowest possible number of variables and implies the other axiomatizations. We show that every finite transitive frame admits a minimal characterization over K4, and that this result can not be extended to K.

We find a short way to construct a formula which axiomatizes a given finite frame of the modal logicK, in the sense that for each finite frameA, we construct a formula A which holds in those and only those frames in which every formula true inA holds.To obtain this result we find, for each finite model and each natural numbern, a formula which holds in those and only those models in which every formula true in , and involving the firstn (...) propositional letters, holds. (shrink)

We define the concepts of minimal p-morphic image and basic p-morphism for transitive Kripke frames. These concepts are used to determine effectively the least number of variables necessary to axiomatize a tabular extension of K4, and to describe the covers and co-covers of such a logic in the lattice of the extensions of K4.

Modal logics with the binary operator Until are considered. It is shown that there exists a continuum of consistent U-logics without Kripke frames, and that each U-logic whose class of order does not have the finite frame property.

In recent times, representation theory has become one of the most productive and interesting sub-fields in democratic theory. Arguably, the most important theoretical innovation are the so-called ‘constructivist’ approaches to political representation. These approaches play a central role in Creating Political Presence: The New Politics of Democratic Representation and The Constructivist Turn in Political Representation, two impressive volumes that take stock of the state of the art in representation theory. I discuss the two volumes by focusing on three broader and (...) interconnected themes: the problem that constructivism is meant to respond to, the tendency of representation theorists to expand the possibilities of representation as broadly as possible, and the normative aspects of political representation and how constructivists deal with them. (shrink)

In recent times, representation theory has become one of the most productive and interesting sub-fields in democratic theory. Arguably, the most important theoretical innovation are the so-called ‘constructivist’ approaches to political representation. These approaches play a central role in Creating Political Presence: The New Politics of Democratic Representation and The Constructivist Turn in Political Representation, two impressive volumes that take stock of the state of the art in representation theory. I discuss the two volumes by focusing on three broader and (...) interconnected themes: the problem that constructivism is meant to respond to, the tendency of representation theorists to expand the possibilities of representation as broadly as possible, and the normative aspects of political representation and how constructivists deal with them. (shrink)

Este artículo intenta poner de manifiesto el papel que jugó el “mar” en el desarrollo de un derecho moderno con pretensiones cada vez más universales.

It is a widely held principle that no one is able to do something that would require the past to have been different from how it actually is. This principle of the fixity of the past has been presented in numerous ways, playing a crucial role in arguments for logical and theological fatalism, and for the incompatibility of causal determinism and the ability to do otherwise. I will argue that, assuming bivalence, this principle is in conflict with standard views about (...) knowledge and the semantics for ‘actually’. I also consider many possible responses to the argument. (shrink)

In this paper, I introduce a “promises and perils” framework for understanding the “soft” impacts of emerging technology, and argue for a eudaimonic conception of well-being. This eudaimonic conception of well-being, however, presupposes that we have something like stable character traits. I therefore defend this view from the “situationist challenge” and show that instead of viewing this challenge as a threat to well-being, we can incorporate it into how we think about living well with technology. Human beings are susceptible to (...) situational influences and are often unaware of the ways that their social and technological environment influence not only their ability to do well, but even their ability to know whether they are doing well. Any theory that attempts to describe what it means for us to be doing well, then, needs to take these contextual features into account and bake them into a theory of human flourishing. By paying careful attention to these contextual factors, we can design systems that promote human flourishing. (shrink)

Populism is widely thought to be in tension with liberal democracy. This article clarifies what exactly is problematic about populism from a liberal–democratic point of view and goes on to develop normative standards that allow us to distinguish between more and less legitimate forms of populism. The point of this exercise is not to dismiss populism in toto; the article strives for a more subtle result, namely, to show that liberal democracy can accommodate populism provided that the latter conforms to (...) particular discursive norms. What the article calls a ‘liberal ethics of populism’ turns out to be closely bound up with a broader ethics of peoplehood, understood as a way of articulating who ‘the people’ are in a way that is compatible with liberal–democratic principles of political justification. Such an ethics, concludes the article, inevitably has a much wider audience than populist political actors: its addressees are all those who seek legitimately to exercise power in the name of the people. (shrink)

Focused on city-scale automation, and using self-driving cars (SDCs) as a case study, this article reflects on the role of AI—and in particular, computer vision systems used for mapping and navigation—as a catalyst for urban transformation. Urban research commonly presents AI and cities as having a one-way cause-and-effect relationship, giving undue weight to AI’s impact on cities and overlooking the role of cities in shaping AI. Working at the intersection of data science and social research, this paper aims to counter (...) this trend by exploring the reverse perspective: how do cities affect the development, and expose the present limits, of SDCs? The contribution of this paper is threefold. First, by comparing urban and nonurban environments and thoroughly examining the relationship between computer vision and city-specific sociality and form, it defines machine autonomy/automation as a function of the sociotechnical milieu in which an AI system operates. Second, and related, the paper problematizes the notion of SDCs as autonomous technologies and the role it plays in envisioning contending policy arrangements and technical solutions for achieving full driving automation. Finally, the article offers insight into a materialist and spatialized understanding of AI—namely, not as an abstract quality susceptible to replication within discrete machines, but rather as a distributed property emerging through embodied interactions among a multiplicity of agents (human, non-human, and technological) within/with their environments. (shrink)

O ESTADO DE DIREITO, A QUEBRA DO PARADIGMA POSITIVISTA E O SURGIMENTO DO ATIVISMO JUDICIAL.

People argue to reconcile differences of opinion, but reconciliation may fail to happen. In these cases, most theorists assume arguers are left with the same disagreement from which they started. This is too optimistic, since disagreement might instead escalate, and this may happen because of the argumentative practice, not in spite of it. These dangers depend on epistemological, pragmatic, and cultural factors, and show why arguers should be careful in picking their dialogical fights.

Popular sovereignty requires that citizens perceive themselves as being able to act and implement decisions, and that they are de facto causally connected to mechanisms of decision making. I argue that the two most common understandings of the exercise of popular sovereignty—which center on direct decision making by the people as a whole and the indirect exercise of democratic agency by elected representatives, respectively—are inadequate in this respect, and go on to suggest a complementary account that stresses the central role (...) of internally democratic and participatory political parties in actualising popular sovereignty, drawing on the democratic theory of Hans Kelsen. (shrink)