We motivate and formalize the idea of sameness by default: two objects are considered the same if they cannot be proved to be different. This idea turns out to be useful for a number of widely different applications, including natural language processing, reasoning with incomplete information, and even philosophical paradoxes. We consider two formalizations of this notion, both of which are based on Reiter’s Default Logic. The first formalization is a new relation of indistinguishability that is introduced by default. We (...) prove that the corresponding default theory has a unique extension, in which every two objects are indistinguishable if and only if their non-equality cannot be proved from the known facts. We show that the indistinguishability relation has some desirable properties: it is reflexive, symmetric, and, while not transitive, it has a transitive “flavor.” The second formalization is an extension (modification) of the ordinary language equality by a similar default: two objects are equal if and only if their non-equality cannot be proved from the known facts. It appears to be less elegant from a formal point of view. In particular, it gives rise to multiple extensions. However, this extended equality is better suited for most of the applications discussed in this paper. (shrink)

We show that the spectrum of a sentence ϕ in Counting Monadic Second Order Logic (CMSOL) using one binary relation symbol and finitely many unary relation symbols, is ultimately periodic, provided all the models of ϕ are of clique width at most k, for some fixed k. We prove a similar statement for arbitrary finite relational vocabularies τ and a variant of clique width for τ-structures. This includes the cases where the models of ϕ are of tree width at most (...) k. For the case of bounded tree-width, the ultimate periodicity is even proved for Guarded Second Order Logic GSOL. We also generalize this result to many-sorted spectra, which can be viewed as an analogue of Parikh's Theorem on context-free languages, and its analogues for context-free graph grammars due to Habel and Courcelle. Our work was inspired by Gurevich and Shelah (2003), who showed ultimate periodicity of the spectrum for sentences of Monadic Second Order Logic where only finitely many unary predicates and one unary function are allowed. This restriction implies that the models are all of tree width at most 2, and hence it follows from our result. (shrink)

This paper presents a dual intention model (DIM) of demonstrations as actions to show the agentive nature of demonstrations. According to the DIM, demonstrations are complex actions that contain as components at least three elements: an abductive intention, a deictic intention, and a basic ostensive act of indication. This paper unpacks these three components and discusses their roles from the viewpoint of the philosophy of action and the philosophy of language. It also shows how the DIM applies in selected practical (...) examples and explains the merits of the model in the context of other views on demonstrations and demonstratives. (shrink)

We prove that compactness is equivalent to the amalgamation property, provided the occurrence number of the logic is smaller than the first uncountable measurable cardinal. We also relate compactness to the existence of certain regular ultrafilters related to the logic and develop a general theory of compactness and its consequences. We also prove some combinatorial results of independent interest.

The book introduces Tadeusz Kotarbiński’s philosophy of action into the mainstream of contemporary action-theoretical debates. Piotr Makowski shows that Kotarbiński–Alfred Tarski’s teacher and one of the most important philosophers of the renowned Lvov-Warsaw school—proposed a groundbreaking, original, and (in at least a few respects) still fresh perspective in action theorizing. The book examines and develops Kotarbiński’s ideas in the context of the most recent discussions in the philosophy of action. The main idea behind Kotarbiński’s action theory—and thus, behind this book—is (...) the significance of the philosophical investigations of the general conditions of effectiveness, efficiency, and economy of intentional actions. Makowski presents and reinterprets Kotarbiński’s views on these dimensions of our activities and sheds new light on the most important areas of action theory. (shrink)

In this article, I examine Michael Bratman’s account of stability in his planning theory of intention. Future-directed intentions should be stable, or appropriately resistant to change, over time. Bratman claims that the norm of stability governs both intentions and plans. The aim of this article is to critically enrich Bratman’s account of stability by introducing plasticity as an additional norm of planning. I construct plasticity as a kind of stability of intentions which supplements Bratman’s notion of “reasonable stability.” Unlike the (...) latter, plasticity applies mainly to cases in which plan states are abandoned without reconsideration. I focus on the intra-theoretical problems of PTI and elucidate: the distinction between future-directed intentions and plans, the conceptual difference between stability and inertia, which is only implicit in PTI, and the role of the environment of the planner, which has a vestigial role in Bratman’s work. I also defend my incorporation of pl... (shrink)

The classical Feferman–Vaught Theorem for First Order Logic explains how to compute the truth value of a first order sentence in a generalized product of first order structures by reducing this computation to the computation of truth values of other first order sentences in the factors and evaluation of a monadic second order sentence in the index structure. This technique was later extended by Läuchli, Shelah and Gurevich to monadic second order logic. The technique has wide applications in decidability and (...) definability theory. Here we give a unified presentation, including some new results, of how to use the Feferman–Vaught Theorem, and some new variations thereof, algorithmically in the case of Monadic Second Order Logic MSOL . We then extend the technique to graph polynomials where the range of the summation of the monomials is definable in MSOL . Here the Feferman–Vaught Theorem for these polynomials generalizes well known splitting theorems for graph polynomials. Again, these can be used algorithmically. Finally, we discuss extensions of MSOL for which the Feferman–Vaught Theorem holds as well. (shrink)

We investigate the expressive power of second-order logic over finite structures, when two limitations are imposed. Let SAA ) be the set of second-order formulas such that the arity of the relation variables is bounded by k and the number of alternations of second-order quantification is bounded by n . We show that this imposes a proper hierarchy on second-order logic, i.e. for every k , n there are problems not definable in AA but definable in AA for some c (...) 1 , d 1 . The method to show this is to introduce the set AUTOSAT of formulas in F which satisfy themselves. We study the complexity of this set for various fragments of second-order loeic. For first-order logic FOL with unbounded alternation of quantifiers AUTOSAT is PSpace complete. For first-order logic FOL n with alternation of quantifiers bounded by n , AUTOSAT is definable in AA . AUTOSAT) is definable in AA for some c 1 , d 1. (shrink)

In a world where politics is often associated with notions such as moral decay, frustration and disappointment, the feeling of betrayal, and of democracy in ...

Previous studies on international reconciliation have focused on the security and economic interests of the countries involved, treating reconciliation as an end-goal rather than an ongoing process. This study divides the process of reconciliation into three stages., which refers to the mending of international relations through institutional change, is the most basic. In the phase, the perpetrator provides the victim with economic compensation for inflicting harm. The third stage,, is reached when the perpetrator acknowledges past wrongdoings and when civil and (...) cultural exchanges are carried out smoothly. (shrink)

Dieses Handbuch bietet erstmals einen umfassenden und systematischen Zugang zu den Theorien des Krieges. Der erste Teil des Werkes ist interdisziplinär angelegt und es werden verschiedene Kriegstheorien dargestellt – von anthropologischen bis hin zu religiösen Ansätzen. Der zweite Teil stellt zentrale Theoretiker des Krieges vor. Der dritte Teil enthält empirische Fallstudien vom Mittelalter bis in die Gegenwart zu Teilaspekten der Kriegstheorien. Insgesamt stellt der Band die Dynamik der theoretischen Entwicklung dar. Dabei berücksichtigt er die jeweiligen politischen, sozioökonomischen und technologischen Faktoren.

Planning organizes our actions and conditions our effective-ness. To understand this philosophical hint better, the author investigates and juxtaposes two important accounts in action theory. He discusses the concept of a plan proposed by Tadeusz Kotarbiński in his praxiology (theory of efcient action), and the so called “planning theory of intention” by Michael E. Bratman. The conceptual meeting of these two proposals helps to remove aws in Kotarbiński’s action theory, it also shows the way, in which we can enrich the (...) idea of plans in the frame-work of intentions. Generally, praxiology occurs to be still an important perspective in action theory, which particularly shows how we can improve our understanding of planning when confronted with infuentialcontemporary accounts. (shrink)

Collected articles on spiritual life based on the life of Bābu Rāṇapurā, mystic-saint poet from Gujarat; previously published in Kacchamitra, a Gujarati daily.

The structure of this paper is as follows. My starting point is psychological flexibility (henceforth, PF) as it has been presented in psychology. Here I offer a synthetic view which embraces the most crucial aspects of flexibility, and describes its functional roles and underlying mechanisms. Secondly, I move my attention onto the field of current action theory and discuss two elementary concepts we commonly use when describing our actions: intention and desire. Of course, there are many “theories of desire” and (...) there is no point in trying (nor even the option) to discuss all of them under one heading. To show where the question of PF sneaks into the scene of action theory, I explore the idea of the resistance of desire, as proposed by Timo Airaksinen. The second concept to investigate at this stage is intention. As in the previous case, it is plain that there are plenty of accounts of intentions and there are many roles they play in the phenomenology of action. For the purposes of this paper, we need only something that can be interpreted as an approach to PF. Such an approach can be found in the idea of stability of intention or a plan, discussed famously by Michael Bratman. According to my interpretation, these two ideas, resistance of desire and stability of intention, allow to initially understand some important aspects of PF in action theory. To get a slightly more comprehensive view – and to supplement the outcomes gained on the grounds of the analyses of these two accounts – I introduce, in the third step, the concept of plasticity which comes from the so-called praxiology proposed by Tadeusz Kotarbiński (Lvov-Warsaw School). I try to show how this concept is still feasible and how it may enrich current philosophical accounts of agential flexibility. The strategy behind this stage of the paper is to enrich the Bratmanian approach to psychological stability. The last part of the paper contains some remarks on the philosophical outcome of the interdisciplinary approach to PF. (shrink)