We present a logical calculus for reasoning about information flow in quantum programs. In particular we introduce a dynamic logic that is capable of dealing with quantum measurements, unitary evolutions and entanglements in compound quantum systems. We give a syntax and a relational semantics in which we abstract away from phases and probabilities. We present a sound proof system for this logic, and we show how to characterize by logical means various forms of entanglement (e.g. the Bell states) and various (...) linear operators. As an example we sketch an analysis of the teleportation protocol. (shrink)

Ancien élève de Heidegger, Alexandru Dragomir (1916-2002) est une figure atypique de la philosophie. Abandonnant l'idée d'une carrière universitaire après la Seconde guerre mondiale, il navigua d'un métier à un autre, refusant catégoriquement d'être publié de son vivant. Il laisse aujourd'hui à nos curiosités ses Banalités métaphysiques, extraites des cahiers dans lesquels il griffonait des notes à sa propre intention. Banalités métaphysiques est la première publication de ce philosophe hors norme, tiré malgré lui de son retrait volontaire.

In this paper, I propose a new way to distinguish between indexicals, like “I” and “today”, and demonstratives, like “she” and “this”. The main test case is the second person singular pronoun “you”. The tradition would generally count it as a demonstrative, because the speaker’s intentions play a role in providing it with a semantic value. I present cross-linguistic data and explanations offered of the data in typology and semantics to show that “you” belongs on the indexical side, and argue (...) that they can be generalized to a novel criterion for distinguishing between indexicals and demonstratives. The central theoretical claim is that the semantic values of indexicals are objects which play certain utterance-related roles, which are fixed independently of the words being used in the utterance. For instance, the speaker plays the speaker role whether or not she uses the word “I”, and the addressee plays that role whether or not the speaker uses the word “you”. Demonstratives, on the other hand, pick out objects that play no such role, and are instead helped by the speaker’s word-specific intentions. (shrink)

We address the old question whether a logical understanding of Quantum Mechanics requires abandoning some of the principles of classical logic. Against Putnam and others (Among whom we may count or not E. W. Beth, depending on how we interpret some of his statements), our answer is a clear "no". Philosophically, our argument is based on combining a formal semantic approach, in the spirit of E. W. Beth's proposal of applying Tarski's semantical methods to the analysis of physical theories, with (...) an empirical-experimental approach to Logic, as advocated by both Beth and Putnam, but understood by us in the view of the operationalrealistic tradition of Jauch and Piron, i. e. as an investigation of "the logic of yes-no experiments" (or "questions"). Technically, we use the recently-developed setting of Quantum Dynamic Logic (Baltag and Smets 2005, 2008) to make explicit the operational meaning of quantum-mechanical concepts in our formal semantics. Based on our recent results (Baltag and Smets 2005), we show that the correct interpretation of quantum-logical connectives is dynamical, rather than purely propositional. We conclude that there is no contradiction between classical logic and (our dynamic reinterpretation of) quantum logic. Moreover, we argue that the Dynamic-Logical perspective leads to a better and deeper understanding of the "non-classicality" of quantum behavior than any perspective based on static Propositional Logic. (shrink)

This paper presents a simple decidable logic of functional dependence LFD, based on an extension of classical propositional logic with dependence atoms plus dependence quantifiers treated as modalities, within the setting of generalized assignment semantics for first order logic. The expressive strength, complete proof calculus and meta-properties of LFD are explored. Various language extensions are presented as well, up to undecidable modal-style logics for independence and dynamic logics of changing dependence models. Finally, more concrete settings for dependence are discussed: continuous (...) dependence in topological models, linear dependence in vector spaces, and temporal dependence in dynamical systems and games. (shrink)

In this paper we aim to examine a novel view on distributive justice, i.e. limitarianism, which claims that it is morally impermissible to be rich. Our main goal is to assess the two arguments provided by Ingrid Robeyns in favour of limitarianism, namely the democratic argument and the argument from unmet urgent needs and the two distinct limitarian views which these arguments give rise to. We claim that strong limitarianism, which is supported by the democratic argument, should be rejected as (...) it fails to fully instantiate the value of political equality, while having some other unattractive implications as well. By contrast, we argue that weak limitarianism, which is supported by the argument from unmet urgent needs, should be endorsed, albeit in a qualified version which also takes responsibility constraints into consideration. (shrink)

The past decade or so has witnessed an increase in the number of philosophical discussions about emergence and reduction in science. However, many of these discussions (though not all) remain too abstract and theoretical, and are wanting with respect to concrete examples taken from the sciences. This dissertation studies the topics of reduction and emergence in the context of a case study. I focus on the case of chemistry and investigate how emergentism can help us secure the autonomy of this (...) discipline in relation to the underlying microphysics. I develop an account of emergence (called functional emergence) that is, I argue, capable of answering the question of why we have chemistry instead of just applied quantum mechanics. I argue that functionally emergent properties in chemistry -- properties that are defined by their behaviour, not by some shared microphysical constituent -- can help us defend the autonomy of chemistry; they allow for the existence of sui generis chemical regularities, which can be used in sui generis chemical explanations. Functional emergence generates difficulties for some accounts of inter-theoretic reduction, but unlike other theories of emergence it is compatible with weaker forms of reductionism. (shrink)

In this article I aim to offer a first critical assessment of the most prominent arguments in favour of restricting the voting rights of senior citizens. The first argument discussed, most thoroughly articulated by van Parijs, maintains that intergenerational justice would be improved under schemes which restrict the voting rights of senior citizens, thereby diminishing their overall electoral weight. The second argument, reconstructed from Lau's defence of child enfranchisement, maintains that the cognitive decline associated with the process of aging should (...) lead us to treat children and senior citizens identically in respect to electoral rights; thus, if we agree that children should not have the right to vote, consistency dictates that senior citizens should be disenfranchised as well. I respond to these arguments with several objections, arguing that the former relies on a number of faulty empirical premises and has deeply unattractive implications for enfranchisement once consistently applied, and that the latter fails to make empirically salient distinctions between children and senior citizens when it comes to the political domain. (shrink)

We investigate the discrete (finite) case of the Popper–Renyi theory of conditional probability, introducing discrete conditional probabilistic models for knowledge and conditional belief, and comparing them with the more standard plausibility models. We also consider a related notion, that of safe belief, which is a weak (non-negatively introspective) type of “knowledge”. We develop a probabilistic version of this concept (“degree of safety”) and we analyze its role in games. We completely axiomatize the logic of conditional belief, knowledge and safe belief (...) over conditional probabilistic models. We develop a theory of probabilistic dynamic belief revision, introducing probabilistic “action models” and proposing a notion of probabilistic update product, that comes together with appropriate reduction laws. (shrink)

In this paper, we investigate the social herding phenomenon known as informational cascades, in which sequential inter-agent communication might lead to epistemic failures at group level, despite availability of information that should be sufficient to track the truth. We model an example of a cascade, and check the correctness of the individual reasoning of each agent involved, using two alternative logical settings: an existing probabilistic dynamic epistemic logic, and our own novel logic for counting evidence. Based on this analysis, we (...) conclude that cascades are not only likely to occur but are sometimes unavoidable by "rational" means: in some situations, the group’s inability to track the truth is the direct consequence of each agent’s rational attempt at individual truth-tracking. Moreover, our analysis shows that this is even so when rationality includes unbounded higher-order reasoning powers, as well as when it includes simpler, non-Bayesian forms of heuristic reasoning. (shrink)

Since Kaplan : 81–98, 1979) first provided a logic for context-sensitive expressions, it has been thought that the only way to construct a logic for indexicals is to restrict it to arguments which take place in a single context— that is, instantaneous arguments, uttered by a single speaker, in a single place, etc. In this paper, I propose a logic which does away with these restrictions, and thus places arguments where they belong, in real world conversations. The central innovation is (...) that validity depends not just on the sentences in the argument, but also on certain abstract relations between contexts. This enrichment of the notion of logical form leads to some seemingly counter-intuitive results: a sequence of sentences may make up a valid argument in one sequence of contexts, and an invalid one in another such sequence. I argue that this is an unavoidable result of context sensitivity in general, and of the nature of indexicals in particular, and that reflection on such examples will lead us to a better understanding of the idea of applying logic to context sensitive expressions, and thus to natural language in general. (shrink)

We present a complete, decidable logic for reasoning about a notion of completely trustworthy evidence and its relations to justifiable belief and knowledge, as well as to their explicit justifications. This logic makes use of a number of evidence-related notions such as availability, admissibility, and “goodness” of a piece of evidence, and is based on an innovative modification of the Fitting semantics for Artemovʼs Justification Logic designed to preempt Gettier-type counterexamples. We combine this with ideas from belief revision and awareness (...) logics to provide an account for explicitly justified knowledge based on conclusive evidence that addresses the problem of omniscience. (shrink)

We propose a refinement of STIT logic to make it suitable to model causal agency and responsibility in basic multi-agent scenarios in which agents can interfere with one another. We do this by supplementing STIT semantics, first, with action types and, second, with a relation of opposing between action types. We exploit these novel elements to represent a test for potential causation, based on an intuitive notion of expected result of an action, and two tests for actual causation from the (...) legal literature, i.e. the but-for and the NESS tests. We then introduce three new STIT operators modeling corresponding notions of causal responsibility, which we call potential, strong, and plain responsibility, and use them to provide a fine-grained analysis of a number of case studies involving both individual agents and groups. (shrink)

We propose a new model for forming and revising beliefs about unknown probabilities. To go beyond what is known with certainty and represent the agent’s beliefs about probability, we consider a plausibility map, associating to each possible distribution a plausibility ranking. Beliefs are defined as in Belief Revision Theory, in terms of truth in the most plausible worlds. We consider two forms of conditioning or belief update, corresponding to the acquisition of two types of information: learning observable evidence obtained by (...) repeated sampling from the unknown distribution; and learning higher-order information about the distribution. The first changes only the plausibility map, but leaves the given set of possible distributions essentially unchanged; the second rules out some distributions, thus shrinking the set of possibilities, without changing their plausibility ordering.. We look at stability of beliefs under either of these types of learning, defining two related notions, as well as a measure of the verisimilitude of a given plausibility model. We prove a number of convergence results, showing how our agent’s beliefs track the true probability after repeated sampling, and how she eventually gains in a sense knowledge of that true probability. Finally, we sketch the contours of a dynamic doxastic logic for statistical learning. (shrink)

We construct logical languages which allow one to represent a variety of possible types of changes affecting the information states of agents in a multi-agent setting. We formalize these changes by defining a notion of epistemic program. The languages are two-sorted sets that contain not only sentences but also actions or programs. This is as in dynamic logic, and indeed our languages are not significantly more complicated than dynamic logics. But the semantics is more complicated. In general, the semantics of (...) an epistemic program is what we call aprogram model. This is a Kripke model of ‘actions’,representing the agents' uncertainty about the current action in a similar way that Kripke models of ‘states’ are commonly used in epistemic logic to represent the agents' uncertainty about the current state of the system. Program models induce changes affecting agents' information, which we represent as changes of the state model, called epistemic updates. Formally, an update consists of two operations: the first is called the update map, and it takes every state model to another state model, called the updated model; the second gives, for each input state model, a transition relation between the states of that model and the states of the updated model. Each variety of epistemic actions, such as public announcements or completely private announcements to groups, gives what we call an action signature, and then each family of action signatures gives a logical language. The construction of these languages is the main topic of this paper. We also mention the systems that capture the valid sentences of our logics. But we defer to a separate paper the completeness proof. (shrink)

In this annotated critical edition of Aristotle’s Metaphysics Lambda Stefan Alexandru draws upon many hitherto unexplored sources of the direct and indirect tradition, inter alia upon an independent Greek manuscript he has discovered in the Vatican Library.

Many of the theories that have been discussed in recent years are distrustful of the anthropological inroads or are openly hostile to them. The problems of the environment, global politics, and the discoveries of biology and medicine create a rich foundation for such attitudes. They are also manifested in the genres of comments that emanate from the domains of rigorous theory and science into the zones of unprovable projections, forecasts, and programs. Perhaps only media philosophy still dares to talk about (...) the need for media anthropology. Yet how is it possible to try to determine what is human in such conditions—among conglomerations of particles (Whitehead-Latour) and entanglements (Barad), in the indiscernibility of the organic and the inorganic? What language can one still use to discuss it—the language of psychoanalytic loss, of scientific impartiality, of literary fiction? Through what concepts can one lay out the path—of function, of environment, of system? This article provides a brief summary of the selection of articles included in the present special issue. The authors of these articles attempt to talk about the human by unleashing this concept in their own way from a cosmic and universal perspective. (shrink)

We present a semantic analysis of the Ramsey test, pointing out its deep underlying flaw: the tension between the “static” nature of AGM revision (which was originally tailored for revision of only purely ontic beliefs, and can be applied to higher-order beliefs only if given a “backwards-looking” interpretation) and the fact that, semantically speaking, any Ramsey conditional must be a modal operator (more precisely, a dynamic-epistemic one). Thus, a belief about a Ramsey conditional is in fact a higher-order belief, hence (...) the AGM revision postulates are not applicable to it, except in their “backwards-looking” interpretation. But that interpretation is consistent only with a restricted (weak) version of Ramsey’s test (in-applicable to already revised theories). The solution out of the conundrum is twofold: either accept only the weak Ramsey test; or replace the AGM revision operator ∗ by a truly “dynamic” revision operator ⊗, which will not satisfy the AGM axioms, but will do something better: it will “keep up with reality”, correctly describing revision with higher-order beliefs. (shrink)

The value in Hartmann’s point of view can be watched from the perspective of some heteronymous plans - an ideal one, which would be “the modality of existence”, and a real one, which would be “the modality of knowing” the value. In Hartmann’s expression we deal with “the absolute character” 1 of values and “the apriority of knowing the values”. It’s interfering here the problem of the validity of values. The question is if the existence of values is reduced to (...) their validity, or if they exist without the dependence of the real states of the world. This validity, for Hartmann, is strictly referring to the second plan, the real one, which is dealing with values. The values are valid “for” – we have here the connection with the existing- but they have their own “world” beside this nip with reality that we call unbiased 2 . The validity of value is aprioristic, no matter the appreciation - like one “pure subjective”, arbitrary - the apriority of value is not depending of some constrain and converge at the level of the logical schemes of thinking. In the general conception of Hartmann’s philosophy the problem of value is diminishing in the analysis of the distinction between the theory of knowledge plan, which is aiming at the subject-object domain, and the ontological one, represented by the relation objective - trans-objective. Although the philosophical analysis will be done from the perspective of the theory of knowledge domain of the relation subject-object, the problem that will concern mostly Hartman will be the objective - trans-objective report seen from the angle of one “critic ontology”, trying to solve the problem of the report between general and specific in the way of being of the axiological structure. (shrink)

In the following lines, we consider the current debate concerning the origin, the specificity and evolution of analytical philosophy. We will try to motivate the idea that the origins and evolution of analytical philosophy are not entirely due to the British philosophers; in fact, this problem cannot be properly explained in terms of a single tradition, which would come true by the removal of another one. Regarding the evolution of analytic philosophy, we identify aspects of the German tradition, the British (...) tradition as well as some new elements generated by the interaction between positivism and American pragmatism. (shrink)

Various writings of mixed genres, drifting between scientific treatises, mystical epiphanies, and prose fiction related to the school of “cosmism,” have been explored for more than fifty years, and the interpretations range from (religious) utopia to theories of sustainable development. The author discusses the question of whether “cosmism” is exclusively “Russian,” compares its general postulates with the techno-Cosmist approaches of the last ten years (including those involving fiction, such as by Eugene Thacker, and the more philosophical approaches, like that applied (...) by Yuk Hui), and proposes clarifying how the Cosmists literally viewed the structure of the world and how they conceptualized its elements as contrasted with the interest of contemporary theorists in openness to planetary and cosmic horizons. The latter, often oriented to nuclear physics and fragmenting “reality” into stochastic agencies whose temporary couplings are formed by cutting and assembling procedures, can be reformulated from the “cosmist” perspective as gleaned in this case from the works of Valerian Murav’ev and Vladimir Vernadsky, with the aid of the categories of expansion and accomplishment. (shrink)

We investigate the process of truth-seeking by iterated belief revision with higher-level doxastic information . We elaborate further on the main results in Baltag and Smets (Proceedings of TARK, 2009a , Proceedings of WOLLIC’09 LNAI 5514, 2009b ), applying them to the issue of convergence to truth . We study the conditions under which the belief revision induced by a series of truthful iterated upgrades eventually stabilizes on true beliefs. We give two different conditions ensuring that beliefs converge to “full” (...) (complete) truth , as well as a condition ensuring only that they converge to true (but not necessarily complete) beliefs. (shrink)

In this article I aim to counter Jason Brennan’s principled objection to the Representativeness Argument for compulsory voting, and to criticize the case in favour of voting lotteries, on which this challenge is predicated. In brief, Brennan claims that compulsory voting should be rejected because there is an alternative system, i.e. a voting lottery, which is able to ensure demographic proportionality in electoral turnouts without diminishing the freedom of citizens. But even on the most favourable conception of freedom which the (...) argument can employ, voting lotteries raise a number of serious concerns in respect to this value. Furthermore, while comparing voting lotteries and compulsory voting on the basis of freedom cannot provide any generalizable support for the former, a plausible case can instead be offered in support of the opposite idea, namely that compulsory voting outperforms voting lotteries with respect to freedom. (shrink)

This paper aims to show that there is a lot of philosophy in the philosophy of chemistry—not only in the problems and questions specific to chemistry, which this science brings up in philosophical discussions, but also in the topics of wider interest like reductionism and emergence, for which chemistry proves to be an ideal case study. The fact that chemical entities and properties are amenable to a quantitative understanding, to measurement and experiment to a greater extent than those in psychology (...) or biology, makes chemistry an ideal case study for those interested in reductionism and emergence. (shrink)

In this article I aim to provide the first normative discussion of barter voting markets, namely markets which allow the trading of votes on issues/elections for votes on other issues/elections. The article is framed within the wider literature on the legal permissibility of vote buying, with a particular focus on the recent debate between Christopher Freiman and James Stacey Taylor. I argue that while Taylor's objections successfully defeat Freiman's case in favour of standard voting markets, they are unable to also (...) defeat the type of voting markets outlined here. Furthermore, I argue that there are at least two plausible prima facie reasons in favour of barter voting markets, grounded in their capacity to contribute to the alleviation of injustice for systematically disadvantaged socio‐economic groups and to their capacity to reduce one form of bad voting, i.e. voting from ignorance. (shrink)

The article conveys the portrait of a man for whom understanding was a matter of the highest spiritual intimacy, a man who continuously disregarded his possible engagement in the public life as a philosopher, finally a man whom we find, in the twilight of his life, concerned with the intricate tension between the “muteness” of philosophy (as being able “only” to double life by means of rational discourse) and religion. Alexandru Dragomir’s portrait is portrayed in comparison to another important (...) Romanian philosopher, Constantin Noica. The comparison is not accidental, since they both come to represent two paradigmatic ways of making philosophy: traditional ontology (centered around Descartes – Kant – Hegel) vs. modern phenomenology (centered around Husserl – Heidegger). (shrink)

The paper aims to clarify several key aspects of Alexandru Dragomir: his amazing “technique” of keeping his entire knowledge in perfect working condition, his exceptional precision of references and his continuous disregard concerning writing. The root of all these peculiarities is traced back to Plato’s cognitive and moral arguments against writing, as expressed in Phaedrus and Seventh Letter. Finally, the article brings to light what seems to be the lesson of Dragomir’s life as a thinker: to rely only on (...) the living thought, that which is written “inside the soul”. (shrink)

This paper discusses the proposal made by Lombardi and Labarca (Found Chem 7:125–148, 2005) that internal realism can secure the ontological autonomy of chemistry. I argue that internal realism is not, by itself, sufficient to accomplish this task. The fact that conceptual schemes may differ with respect to their theoretical virtues, and the possibility that the relations between them may be reductive undermine the premise that each conceptual scheme has an equal right to define its own ontology, which is a (...) key premise in Lombardi and Labarca’s proposal. (shrink)