HAYEK ON LIBERTY, 2ND ED. by John Gray. New York: Basil Blackwell, 1986. $29.95.

Based on an unfinished manuscript by the late philosopher Dallas Willard, this book makes the case that the 20th century saw a massive shift in Western beliefs and attitudes concerning the possibility of moral knowledge, such that knowledge of the moral life and of its conduct is no longer routinely available from the social institutions long thought to be responsible for it. In this sense, moral knowledge--as a publicly available resource for living--has disappeared. Via a detailed survey of main (...) developments in ethical theory from the late 19th through the late 20th centuries, Willard explains philosophy's role in this shift. In pointing out the shortcomings of these developments, he shows that the shift was not the result of rational argument or discovery, but largely of arational social forces--in other words, there was no good reason for moral knowledge to have disappeared. The Disappearance of Moral Knowledge is a unique contribution to the literature on the history of ethics and social morality. Its review of historical work on moral knowledge covers a wide range of thinkers including T.H Green, G.E Moore, Charles L. Stevenson, John Rawls, and Alasdair MacIntyre. But, most importantly, it concludes with a novel proposal for how we might reclaim moral knowledge that is inspired by the phenomenological approach of Knud Logstrup and Emmanuel Levinas. Edited and eventually completed by three of Willard's former graduate students, this book marks the culmination of Willard's project to find a secure basis in knowledge for the moral life. (shrink)

The total and the sharp character of orthodox quantum logic has been put in question in different contexts. This paper presents the basic ideas for a unified approach to partial and unsharp forms of quantum logic. We prove a completeness theorem for some partial logics based on orthoalgebras and orthomodular posets. We introduce the notion of unsharp orthoalgebra and of generalized MV algebra. The class of all effects of any Hilbert space gives rise to particular examples of these structures. Finally, (...) we investigate the relationship between unsharp orthoalgebras, generalized MV algebras, and orthomodular lattices. (shrink)

Fuzzy intuitionistic quantum logics (called also Brouwer-Zadeh logics) represent to non standard version of quantum logic where the connective not is split into two different negation: a fuzzy-like negation that gives rise to a paraconsistent behavior and an intuitionistic-like negation. A completeness theorem for a particular form of Brouwer-Zadeh logic (BZL 3) is proved. A phisical interpretation of these logics can be constructed in the framework of the unsharp approach to quantum theory.

The debate about constructivism in physics has led to different kinds of questions that can be conventionally framed in two classes. One concerns the mathematics that is considered for the theoretical development of physics. The other is concerned with the experimental parts of physical theories. It is unnecessary to observe that the intersection between our two classes of problems is far from being empty. In this paper we will mainly deal with topics belonging to the second class. However, let us (...) briefly mention some important problems that have been debated in the framework of our first class. For instance, the following: to what extent do the undecidability and incompleteness results of classical mathematics affect fragments of physical theories, in such way as to have a “real physical meaning”? are the mathematical arguments that seem to be essential for physics justifiable in the framework of traditional mathematical constructivism?The first question has recently been investigated by Pitowski, Penrose, da Costa, Doria, Mundici, Svozil and others. As expected by most logicians, one can construct undecidable sentences whose physical meaning seems to be hardly questionable. This happens both in classical and in quantum mechanics. (shrink)

Constructibility and complexity play central roles in recent research in computer science, mathematics and physics. For example, scientists are investigating the complexity of computer programs, constructive proofs in mathematics and the randomness of physical processes. But there are different approaches to the explication of these concepts. This volume presents important research on the state of this discussion, especially as it refers to quantum mechanics. This `foundational debate' in computer science, mathematics and physics was already fully developed in 1930 in the (...) Vienna Circle. A special section is devoted to its real founder Hans Hahn, referring to his contribution to the history and philosophy of science. The documentation section presents articles on the early Philipp Frank and on the Vienna Circle in exile. Reviews cover important recent literature on logical empiricism and related topics. (shrink)

This article aims to show that the incompatibility between the application of logic to norms and values and the expressive conception of these notions – basically summed up by the Frege–Geach problem – can be overcome. To this end, a logic is constructed for the expressive conception of norms and values which provides a solution to the Frege–Geach problem and is not affected by the limitations that occur in some previous attempts. More specifically, a pragmatic language LP is introduced which (...) is an extension of the language L of standard propositional logic, obtained by adding two categories of logical-pragmatic signs to the vocabulary of L: the signs of pragmatic mood (,,, standing for assertion, obligation and approval, respectively) and the pragmatic connectives (∼, ∩, ∪, ⊃, ≡, standing for pragmatic negation, conjunction, disjunction, implication and bi-implication, respectively). The notions of pragmatic validity, consistency (satisfiability), compatibility, equivalence and inference are then defined, and some criteria of pragmatic validity are given. It is thus possible to carry out in LP inferences on norms and values expressively understood, adequately formalizing Geach's problematic inferences. (shrink)