Justification logics are epistemic logics that explicitly include justifications for the agents' knowledge. We develop a multi-agent justification logic with evidence terms for individual agents as well as for common knowledge. We define a Kripke-style semantics that is similar to Fitting's semantics for the Logic of Proofs LP. We show the soundness, completeness, and finite model property of our multi-agent justification logic with respect to this Kripke-style semantics. We demonstrate that our logic is a conservative extension of Yavorskaya's minimal bimodal (...) explicit evidence logic, which is a two-agent version of LP. We discuss the relationship of our logic to the multi-agent modal logic S4 with common knowledge. Finally, we give a brief analysis of the coordinated attack problem in the newly developed language of our logic. (shrink)

Logical theories for representing knowledge are often plagued by the so-called Logical Omniscience Problem. The problem stems from the clash between the desire to model rational agents, which should be capable of simple logical inferences, and the fact that any logical inference, however complex, almost inevitably consists of inference steps that are simple enough. This contradiction points to the fruitlessness of trying to solve the Logical Omniscience Problem qualitatively if the rationality of agents is to be maintained. We provide a (...) quantitative solution to the problem compatible with the two important facets of the reasoning agent: rationality and resource boundedness. More precisely, we provide a test for the logical omniscience problem in a given formal theory of knowledge. The quantitative measures we use are inspired by the complexity theory. We illustrate our framework with a number of examples ranging from the traditional implicit representation of knowledge in modal logic to the language of justification logic, which is capable of spelling out the internal inference process. We use these examples to divide representations of knowledge into logically omniscient and not logically omniscient, thus trying to determine how much information about the reasoning process needs to be present in a theory to avoid logical omniscience. (shrink)

We develop multi-conclusion nested sequent calculi for the fifteen logics of the intuitionistic modal cube between IK and IS5. The proof of cut-free completeness for all logics is provided both syntactically via a Maehara-style translation and semantically by constructing an infinite birelational countermodel from a failed proof search. Interestingly, the Maehara-style translation for proving soundness syntactically fails due to the hierarchical structure of nested sequents. Consequently, we only provide the semantic proof of soundness. The countermodel construction used to prove completeness (...) required a completely novel approach to deal with two independent sources of non-termination in the proof search present in the case of transitive and Euclidean logics. (shrink)

The debate around the notions of a priori knowledge and a posteriori knowledge has proven crucial for the development of many fields in philosophy, such as metaphysics, epistemology, metametaphysics etc. We advocate that the recent debate on the two notions is also fruitful for man-made distributed computing systems and for the epistemic analysis thereof. Following a recently proposed modal and fallibilistic account of a priori knowledge, we elaborate the corresponding concept of a priori belief: We propose a rich taxonomy of (...) types of a priori beliefs and their role for the different agents that participate in the system engineering process, which match the existing view exceedingly well and are particularly promising for explaining and dealing with unexpected behaviors in fault-tolerant distributed systems. Developing such a philosophical foundation will provide a sound basis for eventually implementing our ideas in a suitable epistemic reasoning and analysis framework and, hence, constitutes a mandatory first step for developing methods and tools to cope with the various challenges that emerge in such systems. (shrink)

While Hermann Levin Goldschmidt didn’t read Yiddish anarchists, there seems to have been a convergent evolution in their thinking. Goldschmidt’s looking up to Jewish lore as a source of liberating creativity is commonly encountered in Yiddish anarchist texts. His view of action as a constant response to internal and external challenges in the struggle for an open future is developed by Isaac Nachman Steinberg on the basis of nineteenth-century vitalism. Goldschmidt’s theory of anarchist individualism as willed self-limiting solidarity has a (...) compelling parallel in Hillel Solotaroff’s view of history. His use of impressionism and photography to eternalize the immediacy of human actuality is akin to Rudolf Rocker’s championing of decadent literature. In both cases, the goal of anarchism is not a dictatorship of the former downtrodden, but a continuous and contradictory evolution of freedom in ever-changing contexts. (shrink)

Models are of central importance in many scientific contexts. The centrality of models such as inflationary models in cosmology, general-circulation models of the global climate, the double-helix model of DNA, evolutionary models in biology, agent-based models in the social sciences, and general-equilibrium models of markets in their respective domains is a case in point (the Other Internet Resources section at the end of this entry contains links to online resources that discuss these models). Scientists spend significant amounts of time building, (...) testing, comparing, and revising models, and much journal space is dedicated to interpreting and discussing the implications of models. In short, models are one of the principal instruments of modern science. (shrink)

Machine ethics and robot rights are quickly becoming hot topics in artificial intelligence and robotics communities. We will argue that attempts to attribute moral agency and assign rights to all intelligent machines are misguided, whether applied to infrahuman or superhuman AIs, as are proposals to limit the negative effects of AIs by constraining their behavior. As an alternative, we propose a new science of safety engineering for intelligent artificial agents based on maximizing for what humans value. In particular, we challenge (...) the scientific community to develop intelligent systems that have human-friendly values that they provably retain, even under recursive self-improvement. (shrink)

The volume contains twenty essays devoted to the philosophy of mathematics and the history of logic. They have been divided into four parts: general philosophical problems of mathematics, Hilbert's program vs. the incompleteness phenomenon, philosophy of mathematics in Poland, mathematical logic in Poland. Among considered problems are: epistemology of mathematics, the meaning of the axiomatic method, existence of mathematical objects, distinction between proof and truth, undefinability of truth, Goedel's theorems and computer science, philosophy of mathematics in Polish mathematical and logical (...) schools, beginnings of mathematical logic in Poland, contribution of Polish logicians to recursion theory. (shrink)

The paper proposes an outline of a reconciliatory approach to the perennial controversy between epistemological realism and anti-realism (constructionism). My main conceptual source in explaining this view is the philosophy of pragmatism, more specifically, the epistemological theories of George H. Mead, John Dewey, and also William James’ radical empiricism. First, the paper analyzes the pragmatic treatment of the goal-directedness of action, especially with regard to Mead’s notion of attitudes, and relates it to certain contemporary epistemological theories provided by the cognitive (...) sciences (Maturana, Rizzolatti, Clark). Against this background, the paper presents a philosophical as well as empirical justification of why we should interpret the environment and its objects in terms of possibilities for action. In Mead’s view, the objects and events of our world emerge within stable patterns of organism-environment interactions, which he called “perspectives”. According to pragmatism as well as the aforementioned cognitive scientists, perception and other cognitive processes include not only neural processes in our heads but also the world itself. Elaborating on Mead’s concept of perspectives, the paper argues in favor of the epistemological position called “constructive realism.”. (shrink)

John Dewey's Ethics: Democracy as Experience.

Williams’s famous argument against immortality rests on the idea that immortality cannot be desirable, at least for human beings, and his contention has spawned a cottage industry of responses. As I will intend to show, the arguments over his view rest on both a difference of temperament and a difference in the sense of desire being used. The former concerns a difference in whether one takes a forward-looking or a backward-looking perspective on personal identity; the latter a distinction between our (...) normal desire to continue living and the kind of desire implied in desiring immortality. Showing that there is some sense of identity and desire that support Williams’s conclusion goes some way toward providing support for his argument, if not a full-fledged defense of it. (shrink)

John Fischer has recently argued that the value of acting freely is the value of self-expression. Drawing on David Velleman’s earlier work, Fischer holds that the value of a life is a narrative value and free will is valuable insofar as it allows us to shape the narrative structure of our lives. This account rests on Fischer’s distinction between regulative control and guidance control. While we lack the former kind of control, on Fischer’s view, the latter is all that is (...) needed for self-expression. I first develop Fischer’s narrative account, focusing on his reliance on temporal loops as giving us control over the value of our lives. Second, I argue that the narrative account grants us greater power over the past than Fischer would allow: since narrative allows not only for changes in how we feel about episodes in our past but what those episodes in fact were, it allows for a kind of retroactive self-constitution. Finally, I suggest that this modification of the narrative view opens the possibility of a conception of freedom far stronger than guidance control. It does not give us the libertarian control over whether to choose A or B in the present, but it does provide a measure of control over the sort of person an agent has been, and thus whether she is the sort of person who will choose A or B in the future. (shrink)

Most scientific models are not physical objects, and this raises important questions. What sort of entity are models, what is truth in a model, and how do we learn about models? In this paper I argue that models share important aspects in common with literary fiction, and that therefore theories of fiction can be brought to bear on these questions. In particular, I argue that the pretence theory as developed by Walton (1990, Mimesis as make-believe: on the foundations of the (...) representational arts. Harvard University Press, Cambridge/MA) has the resources to answer these questions. I introduce this account, outline the answers that it offers, and develop a general picture of scientific modelling based on it. (shrink)

Kuznet︠s︡ov, I. V. Kategorii︠a︡ prichinnosti i ee poznavatelʹnoe znachenie.--Shali︠u︡tin, S. M. Ob otrazhenii kak obshchem svoĭstve materii.--I︠U︡rgelenas, D. I. Teorii︠a︡ otrazhenii︠a︡ i poni︠a︡tie informat︠s︡ii.--Korneeva, A. I. Vozrastai︠u︡shchai︠a︡ rolʹ logicheskogo myshlenii︠a︡ v poznanii mira.--Klimashevskiĭ, G. Teoretiko-poznavatelʹnai︠a︡ rolʹ myslennogo ėksperimenta v fizike.-- Podosetnik, V. M. Gnoseologicheskoe znachenie faktov v poznanii obshchestvennykh i︠a︡vleniĭ.

Heidegger, like Kierkegaard, has recently been claimed as a narrativist about selves. From this Heideggerian perspective, we can see how narrative expands upon the psychological view, adding a vital teleological dimension to the understanding of selfhood while denying the reductionism implicit in the psychological approach. Yet the narrative approach also inherits the neo-Lockean emphasis on the past as determining identity, whereas the self is fundamentally about the future. Death is crucial on this picture, not as allowing for the possibility of (...) a final meaning to our lives, but as determining Dasein as ‘pure unactualizable possibility.’ Ultimately, therefore, narrative is not what constitutes selfhood – but this does not mean that narrative is not relevant to personal identity, because narrative allows identity to be expressed in action. (shrink)

Le Polonais Roman Ingarden (1893-1970) est un phénoménologue disciple de Husserl à Göttingen. Leur dialogue continu représente le conflit classique entre idéalisme et réalisme, mais aussi la tension qu'est l'articulation entre la description eidétique de régions ontologiques et l'entreprise de constitution génétique du monde. Une première approche à travers quatre des textes d'Ingarden.