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.
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.
The goal of this paper is to present a collection of properties of the set of atoms and the set of finite injective tuples of atoms, as well as of the powersets of atoms in the framework of finitely supported structures. Some properties of atoms are obtained by translating classical Zermelo–Fraenkel results into the new framework, but several important properties are specific to finitely supported structures.
The weaver ant, Oecophylla smaragdina Fabricius (Hymenoptera: Formicidae), has long been known as perhaps the first example of human manipulation of a natural predator population to enhance the natural biological control of insect pests. The practice of ant husbandry in Vietnamese citrus orchards and the knowledge associated with the use of weaver ants in the Mekong delta are described. In contrast to other regions of Asia, where weaver ants are noted for their role in the protection of citrus from insect (...) damage, citrus farmers in the Mekong delta explain the benefits of ant husbandry in terms of an improvement in fruit quality, likened to the influence of fertilizers, that occurs in direct response to excretory products deposited by the weaver ants as they patrol the fruit. A series of tests, carried out in 1993–94, rated the external shine, sweetness, juiciness, and overall appeal, as characteristics of fruit quality, for paired comparisons of sweet orange, mandarin, and pummelo fruit that had been grown in the presence of weaver ants or from which ants had been excluded. The tests indicate a strong influence of the presence of the weaver ant on external shine, juiciness, and overall appeal for each of the citrus fruits, but particularly for mandarin. The significance of these results and ant husbandry practices in the Mekong delta are discussed in relation to the development of citrus production in Vietnam. (shrink)
According to the social contract theory, in order to achieve justice, people grouped themselves in societies. Historically speaking, judges appeared long before the legislator which means that justice was the first element of the social life. Therefore, it expresses the social ethics of a particular time and requires a minimum of credibility. Excessive pragmatism and utilitarianism have kidnapped more and more of what is humane, superior and sacred in the act of justice, and “secularized” it. As Eliade said in The (...) Sacred and the Profane, the sacred is something which is totally different, a space of radical otherness which overshadows the physical territory. This shading manifests itself through limitation, sequencing, reiteration and keeping what is sacred there, even in a courtroom, through ritualization. (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)
Alexandru Dragomir became widely known in Romania as a philosopher 2 years after his death, in 2004. He had no prior publications and only a few of his close acquaintances were even aware of his work as a thinker. The editors of the five volumes of his posthumous papers have from the onset tried to present Dragomir, a former doctoral student of Heidegger, as a phenomenologist, while this interpretation is today well-established. The following paper tries to submit this interpretation (...) to a closer scrutiny, on the one hand, by addressing the history of Dragomir’s publication and reception in Romania and abroad, and on the other hand, by analyzing several aspects of his oeuvre which do indeed hold close resemblance to aspects of the phenomenological method, even though they actually have quite different motivations. (shrink)
This is the second edition of Aristotle’s Metaphysics Lambda within two years, following Silvia Fazzo’s Il libro Lambda della Metafisica di Aristotele. Unlike Fazzo, Alexandru does not accompany the Greek text with a translation, but he should be thanked for providing a most valuable and exhaustive critical apparatus, which makes almost unnecessary any further work on the available sources. Alexandru has examined with great accuracy all forty-three Greek manuscripts that transmit Lambda and has fully collated the thirteen manuscripts (...) that are independent according to the stemma codicum established by Dieter Harlfinger; he adds to them a hitherto unknown manuscript of the β-family, namely the... (shrink)
Après des études de droit et de philosophie à l'Université de Bucarest, Alexandru Dragomir part à Fribourg-en-Brisgau comme doctorant de Martin Heidegger. Il y reste deux ans; en 1943 il est rappelé en Roumanie et envoyé au front. Après la guerre, sous le nouveau régime, il ne peut pas poursuivre une carrière universitaire. Il meurt en 2002 à Bucarest sans avoir rien publié. Ce n'est qu'après sa mort que ses cahiers sont découverts et publiés. L'œuvre de Dragomir comprend cinq (...) volumes, parus à Bucarest, aux Éditions Humanitas. Deux sont parus en traduction française chez Vrin : Banalités métaphysiques et Cahiers du temps. Cet article présente sa personnalité et son œuvre, notamment les Cahiers du temps, qui renferment la recherche de toute sa vie. Dragomir y développe sa propre théorie sur la nature du temps, tout en faisant des commentaires des textes classiques de la philosophie qui portent sur ce sujet. Des traductions en allemand et en anglais des Cahiers du temps paraîtront bientôt. Between 1933 and 1939 Alexandru Dragomir studied philosophy and law at the University of Bucharest. In 1941 he was awarded a Humboldt Fellowship, which allowed him to enroll as a doctoral student at the University of Freiburg im Breisgau, Germany, under the supervision of Martin Heidegger. In 1943 he was drafted into the Romanian armed forces and left Freiburg without a degree. In Romania, under the communist regime, he could not pursue an academic career. He died in 2002 without publishing anything. His work has been published posthumously in five volumes by Humanitas Press. Two of the volumes have been published in French translation by Jean Vrin Press : Banalités métaphysiques [Metaphysical Banalities] and Cahiers du temps [Notebooks on Time]. This article offers an overview of Dragomir's personality and work, with an emphasis on his Notebooks on Time — his lifelong research on the nature of time. In these notebooks he develops his own views on time and comments on the classical philosophical texts that deal with the subject. (shrink)
Ancien élève de Heidegger, Alexandru Dragomir 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 aujourdh’ui à nos curiosités ses Banalités métaphysiques, extraits 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.
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)
The ethics of voting is a new field of academic research, uniting debates in ethics and public policy, democratic theory and more empirical studies of politics. A central question in this emerging field is whether or not voters should be legally required to vote. This chapter examines different arguments on behalf of compulsory voting, arguing that these do not generally succeed, although compulsory voting might be justified in certain special cases. However, adequately specifying the forms of voluntary voting that are (...) consistent with democratic norms is likely to be philosophically complex and politically controversial. (shrink)
Public announcement logic is an extension of multiagent epistemic logic with dynamic operators to model the informational consequences of announcements to the entire group of agents. We propose an extension of public announcement logic with a dynamic modal operator that expresses what is true after any announcement: after which , does it hold that Kφ? We give various semantic results and show completeness for a Hilbert-style axiomatization of this logic. There is a natural generalization to a logic for arbitrary events.
We take a logical approach to threshold models, used to study the diffusion of opinions, new technologies, infections, or behaviors in social networks. Threshold models consist of a network graph of agents connected by a social relationship and a threshold value which regulates the diffusion process. Agents adopt a new behavior/product/opinion when the proportion of their neighbors who have already adopted it meets the threshold. Under this diffusion policy, threshold models develop dynamically towards a guaranteed fixed point. We construct a (...) minimal dynamic propositional logic to describe the threshold dynamics and show that the logic is sound and complete. We then extend this framework with an epistemic dimension and investigate how information about more distant neighbors’ behavior allows agents to anticipate changes in behavior of their closer neighbors. Overall, our logical formalism captures the interplay between the epistemic and social dimensions in social networks. (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 formalise a notion of dynamic rationality in terms of a logic of conditional beliefs on (doxastic) plausibility models. Similarly to other epistemic statements (e.g. negations of Moore sentences and of Muddy Children announcements), dynamic rationality changes its meaning after every act of learning, and it may become true after players learn it is false. Applying this to extensive games, we “simulate” the play of a game as a succession of dynamic updates of the original plausibility model: the epistemic situation (...) when a given node is reached can be thought of as the result of a joint act of learning (via public announcements) that the node is reached. We then use the notion of “stable belief”, i.e. belief that is preserved during the play of the game, in order to give an epistemic condition for backward induction: rationality and common knowledge of stable belief in rationality. This condition is weaker than Aumann’s and compatible with the implicit assumptions (the “epistemic openness of the future”) underlying Stalnaker’s criticism of Aumann’s proof. The “dynamic” nature of our concept of rationality explains why our condition avoids the apparent circularity of the “backward induction paradox”: it is consistent to (continue to) believe in a player’s rationality after updating with his irrationality. (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)
We study the learning power of iterated belief revision methods. Successful learning is understood as convergence to correct, i.e., true, beliefs. We focus on the issue of universality: whether or not a particular belief revision method is able to learn everything that in principle is learnable. We provide a general framework for interpreting belief revision policies as learning methods. We focus on three popular cases: conditioning, lexicographic revision, and minimal revision. Our main result is that conditioning and lexicographic revision can (...) drive a universal learning mechanism, provided that the observations include only and all true data, and provided that a non-standard, i.e., non-well-founded prior plausibility relation is allowed. We show that a standard, i.e., well-founded belief revision setting is in general too narrow to guarantee universality of any learning method based on belief revision. We also show that minimal revision is not universal. Finally, we consider situations in which observational errors may occur. Given a fairness condition, which says that only finitely many errors occur, and that every error is eventually corrected, we show that lexicographic revision is still universal in this setting, while the other two methods are not. (shrink)
Kuhn argued that scientific theory choice is, in some sense, a rational matter, but one that is not fully determined by shared objective scientific virtues like accuracy, simplicity, and scope. Okasha imports Arrow’s impossibility theorem into the context of theory choice to show that rather than not fully determining theory choice, these virtues cannot determine it at all. If Okasha is right, then there is no function from ‘preference’ rankings supplied by scientific virtues over competing theories to a single all-things-considered (...) ranking. This threatens the rationality of science. In this paper we show that if Kuhn’s claims about the role that subjective elements play in theory choice are taken seriously, then the threat dissolves. (shrink)
The classical rule of Repetition says that if you take any sentence as a premise, and repeat it as a conclusion, you have a valid argument. It's a very basic rule of logic, and many other rules depend on the guarantee that repeating a sentence, or really, any expression, guarantees sameness of referent, or semantic value. However, Repetition fails for token-reflexive expressions. In this paper, I offer three ways that one might replace Repetition, and still keep an interesting notion of (...) validity. Each is a fine way to go for certain purposes, but I argue that one in particular is to be preferred by the semanticist who thinks that there are token-reflexive expressions in natural languages. (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)
Synonymy, at its most basic, is sameness of meaning. A token-reflexive expression is an expression whose meaning assigns a referent to its tokens by relating each particular token of that particular expression to its referent. In doing so, the formulation of its meaning mentions the particular expression whose meaning it is. This seems to entail that no two token-reflexive expressions are synonymous, which would constitute a strong objection against token-reflexive semantics. In this paper, I propose and defend a notion of (...) synonymy for token-reflexive expressions that allows such expressions to be synonymous, while being a fairly conservative extension of the customary notion of synonymy. (shrink)
In an increasingly urbanized world, construction industry is called upon to serve the needs of human society, such as environmental protection and safety in terms of infrastructure. In this context, a sustainable and ethical development means a close connection between buildings and environment. This connection can be achieved through, for example, the concept of ecological concrete or green concrete, as it is often called. The conventional process of obtaining cement and mineral aggregates from the concrete composition generates pollution, especially through (...) greenhouse gas emissions. Also, one should not ignore the fact that extraction of the raw materials affects the habitats of the sites and of the neighboring areas. When construction materials are questioned, the ethical issues lay not in the means of expression, but mainly in the means of production. More to the point, the present contribution aimed to find solutions for enhancing the adhesion of vegetal aggregates with the cement matrix, in order to obtain a material with optimal mechanical properties, which is valued as an ethical approach of building industry. Results showed that plant aggregates can be used to obtain a building material which can be improved by using partial substitution of cement by silica fume, fly ash, or by using additives and that green concrete as an environmentally friendly material offers the alternative for lower energy use and fewer CO2 emissions. Marketers must understand not only the advantages of these green materials, but also that they have an ethical commitment to provide consumers with environmentally friendly materials. (shrink)
The prospect of cognitive enhancement well beyond current human capacities raises worries that the fundamental equality in moral status of human beings could be undermined. Cognitive enhancement might create beings with moral status higher than persons. Yet, there is an expressibility problem of spelling out what the higher threshold in cognitive capacity would be like. Nicholas Agar has put forward the bold claim that we can show by means of inductive reasoning that indefinite cognitive enhancement will probably mark a difference (...) in moral status. The hope is that induction can determine the plausibility of post‐personhood existence in the absence of an account of what the higher status would be like. In this article, we argue that Agar's argument fails and, more generally, that inductive reasoning has little bearing on assessing the likelihood of post‐personhood in the absence of an account of higher status. We conclude that induction cannot bypass the expressibility problem about post‐persons. (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)
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)
In this paper we show how ideas coming from two areas of research in logic can reinforce each other. The first such line of inquiry concerns the "dynamic turn" in logic and especially the formalisms inspired by Propositional Dynamic Logic (PDL); while the second line concerns research into the logical foundations of Quantum Physics, and in particular the area known as Operational Quantum Logic, as developed by Jauch and Piron (Helve Phys Acta 42: 842-848, 1969), Pirón (Foundations of Quantum Physics, (...) 1976). By bringing these areas together we explain the basic ingredients of Dynamic Quantum Logic, a new direction of research in the logical foundations of physics. (shrink)
We formalise a notion of dynamic rationality in terms of a logic of conditional beliefs on plausibility models. Similarly to other epistemic statements, dynamic rationality changes its meaning after every act of learning, and it may become true after players learn it is false. Applying this to extensive games, we "simulate" the play of a game as a succession of dynamic updates of the original plausibility model: the epistemic situation when a given node is reached can be thought of as (...) the result of a joint act of learning that the node is reached. We then use the notion of "stable belief, i.e. belief that is preserved during the play of the game, in order to give an epistemic condition for backward induction: rationality and common knowledge of stable belief in rationality. This condition is weaker than Aumann's and compatible with the implicit assumptions underlying Stalnaker's criticism of Aumann's proof. The "dynamic" nature of our concept of rationality explains why our condition avoids the apparent circularity of the "backward induction paradox": it is consistent to believe in a player's rationality after updating with his irrationality. (shrink)