Publisher's Note: Hannah Arendt's last philosophical work was an intended three-part project entitled The Life of the Mind. Unfortunately, Arendt lived to complete only the first two parts, Thinking and Willing. Of the third, Judging, only the title page, with epigraphs from Cato and Goethe, was found after her death. As the titles suggest, Arendt conceived of her work as roughly parallel to the three Critiques of Immanuel Kant. In fact, while she began work on The Life of the Mind, Arendt lectured on "Kant's Political Philosophy," using the Critique of Judgment as her main text. The present volume brings Arendt's notes for these lectures together with other of her texts on the topic of judging and provides important clues to the likely direction of Arendt's thinking in this area.

Introduction: From a logical point of view the measurement problem of quantum mechanics, can be described as a characteristic question of 'semantical closure' of a theory: to what extent can a consistent theory (in this case 2R) be closed with respect to the objects and the concepfs which are described and expressed in its metatheory?

Summary: This article provides the basics of a typical logic, sometimes called 'classical elementary logic' or 'classical first-order logic', in a rigorous yet accessible manner. Section 2 develops a formal language, with a syntax and grammar. Section 3 sets up a deductive system for the language, in the spirit of natural deduction. Section 4 provides a model-theoretic semantics. Section 5 turns to the relationships between the deductive system and the semantics, and in particular, the relationship between derivability and validity. The authors show that an argument is derivable only if it is valid (soundness). Then they establish a converse: that an argument is valid only if it is derivable (completeness). They also briefly indicate other features of the logic, some of which are corollaries to soundness and completeness. The final section, Section 6, is devoted to a brief examination of the philosophical position that classical logic is 'the one right logic'.

Publisher's Note: Although sequent calculi constitute an important category of proof systems, they are not as well known as axiomatic and natural deduction systems. Addressing this deficiency, Proof Theory: Sequent Calculi and Related Formalisms presents a comprehensive treatment of sequent calculi, including a wide range of variations. It focuses on sequent calculi for various non-classical logics, from intuitionistic logic to relevance logic, linear logic, and modal logic. In the first chapters, the author emphasizes classical logic and a variety of different sequent calculi for classical and intuitionistic logics. She then presents other non-classical logics and meta-logical results, including decidability results obtained specifically using sequent calculus formalizations of logics.

Abstract: The aim of this paper is to summarize a particular approach of doing metaphysics through physics - the primitive ontology approach. The idea is that any fundamental physical theory has a well-defined architecture, to the foundation of which there is the primitive ontology, which represents matter. According to the framework provided by this approach when applied to quantum mechanics, the wave function is not suitable to represent matter. Rather, the wave function has a nomological character, given that its role in the theory is to implement the law of evolution for the primitive ontology.

Publisher's Note: Not limited to merely mathematics, probability has a rich and controversial philosophical aspect. 'A Philosophical Introduction to Probability' showcases lesser-known philosophical notions of probability and explores the debate over their interpretations. Galavotti traces the history of probability and its mathematical properties and then discusses various philosophical positions on probability, from the Pierre Simon de Laplace's 'classical' interpretation of probability to the logical interpretation proposed by John Maynard Keynes. This book is a valuable resource for students in philosophy and mathematics and all readers interested in notions of probability

Abstract: This paper argues that it is scientific realists who should be most concerned about the issue of Platonism and anti-Platonism in mathematics. If one is merely interested in accounting for the practice of pure mathematics, it is unlikely that a story about the ontology of mathematical theories will be essential to such an account. The question of mathematical ontology comes to the fore, however, once one considers our scientific theories. Given that those theories include amongst their laws assertions that imply the existence of mathematical objects, scientific realism, when construed as a claim about the truth or approximate truth of our scientific theories, implies mathematical Platonism. However, a standard argument for scientific realism, the 'no miracles' argument, falls short of establishing mathematical Platonism. As a result, this argument cannot establish scientific realism as it is usually defined, but only some weaker position. Scientific 'realists' should therefore either redefine their position as a claim about the existence of unobservable physical objects, or alternatively look for an argument for their position that does establish mathematical Platonism.

Summary: This book is an introductory textbook on mathematical logic. It covers Propositional Logic and Predicate Logic. For each of these formalisms it presents its syntax and formal semantics as well as a tableaux-style method of consistency-checking and a natural deduction-style deductive calculus. Moreover, it discusses the metatheory of both logics.

Abstract: In this chapter, we examine a few potential problems when inquiring into the ethics of medieval Christian and Islamic mystical traditions: First, there are terminological and methodological worries about defining mysticism and doing comparative philosophy in general. Second, assuming that the Divine represents the highest Good in such traditions, and given the apophaticism on the part of many mystics in both religions, there is a question of whether or not such traditions can provide a coherent theory of value. Finally, the antinomian tendencies and emphasis on passivity of some mystics might lead one to wonder whether their prescriptive exhortations can constitute a coherent theory of right action. We tackle each of these concerns in turn and discuss how they might be addressed, in an attempt to show how medieval mysticism, as a fundamentally practical enterprise, deserves more attention from practical and moral philosophy than it has thus far received.

Abstract: The paper challenges Williamson's safety based explanation for why we cannot know the cut-off point of vague expressions. We assume throughout (most of) the paper that Williamson is correct in saying that vague expressions have sharp cut-off points, but we argue that Williamson's explanation for why we do not and cannot know these cut-off points is unsatisfactory. In sect 2 we present Williamson's position in some detail. In particular, we note that Williamson's explanation relies on taking a particular safety principle ('Meta-linguistic belief safety' or 'MBS') as a necessary condition on knowledge. In section 3, we show that even if MBS were a necessary condition on knowledge, that would not be sufficient to show that we cannot know the cut-off points of vague expressions. In section 4, we present our main case against Williamson's explanation: we argue that MBS is not a necessary condition on knowledge, by presenting a series of cases where one's belief violates MBS but nevertheless constitutes knowledge. In section 5, we present and respond to an objection to our view. And in section 6, we briefly discuss the possible directions a theory of vagueness can take, if our objection to Williamson's theory is taken on board.