现代世界观中的意识及其哲学难题

人是具身心智的存在者,其存在方式独特性在于:他既依赖于物理形态的身体,又有存在论上不可还原性的主观性。因此如何在现代世界观中一致且完备地解释和理解人遂成了心智哲学的大问题。如果坚持现代世界观的基本立场一致性,那么对意识的解释和理解不可避免存在着"难问题"所界定的不完备性。人们大致从三个进路来处理不完备性的局面。然而,原则上它们都无法实现一致且完备的要求,因为这里存在一个根本的局限,即不可能通过认识论的方法在两种存在论形式(无和有)之间实现等价转换。尽管在认识论上这是一个悲观的结局,但另一方面它又是积极的,因为它显示了个体经验在存在论上是独一无二的。     

Kripke Models,Distributive Lattices,and Medvedev Degrees

We define a variant of the standard Kripke semantics for intuitionistic logic, motivated by the connection between constructive logic and the Medvedev lattice. We show that while the new semantics is still complete, it gives a simple and direct correspondence between Kripke models and algebraic structures such as factors of the Medvedev lattice. Presented by Daniele Mundici     

Irreflexive Modality in the Intuitionistic Propositional Logic and Novikov Completeness

A. Kuznetsov considered a logic which extended intuitionistic propositional logic by adding a notion of 'irreflexive modality'. We describe an extension of Kuznetsov's logic having the following properties: (a) it is the unique maximal conservative (over intuitionistic propositional logic) extension of Kuznetsov's logic; (b) it determines a new unary logical connective w.r.t. Novikov's approach, i.e., there is no explicit expression within the system for the additional connective; (c) it is axiomatizable by means of one simple additional axiom scheme.     

Combinations of Tense and Modality for Predicate Logic

In recent years combinations of tense and modality have moved into the focus of logical research. From a philosophical point of view, logical systems combining tense and modality are of interest because these logics have a wide field of application in original philosophical issues, for example in the theory of causation, of action, etc. But until now only methods yielding completeness results for propositional languages have been developed. In view of philosophical applications, analogous results with respect to languages of predicate logic are desirable, and in this paper I present two such results. The main developments in this area can be split into two directions, differing in the question whether the ordering of time is world-independent or not. Semantically, this difference appears in the discussion whether T×W-frames or Kamp-frames (resp. Ockham-frames) provide a suitable semantics for combinations of tense and modality. Here, two calculi are presented, the first adequate with respect to Kamp-semantics, the second to T×W-semantics. (Both calculi contain an appropriate version of Gabbay's irreflexivity rule.) Furthermore, the proposed constructions of canonical frames simplify some of those which have hitherto been discussed.     

Basic Logic,K4, and Persistence

We characterize the first-order formulas with one free variable that are preserved under bisimulation and persistence or strong persistence over the class of Kripke models with transitive frames and unary persistent predicates. This revised version was published online in June 2006 with corrections to the Cover Date.     

The problem with descriptive correctness

In the 1980s and early 1990s, the normativity of meaning was thought to be more-or-less ‘incontestable.’ But in the last 25 years, many philosophers of mind and language have contested it in several seemingly different ways. This, however, is somewhat illusory. There is an unappreciated commonality among most anti-normativist arguments, and this commonality, I argue, poses a problem for anti-normativism. The result, however, is not a wholesale rejection of anti-normativism. Rather, an insight from the anti-normativist position can be harnessed to reveal an unappreciated position in the normativity of meaning debate.     

Completeness and super-valuations

This paper uses the notion of Galois-connection to examine the relation between valuation-spaces and logics. Every valuation-space gives rise to a logic, and every logic gives rise to a valuation space, where the resulting pair of functions form a Galois-connection, and the composite functions are closure-operators. A valuation-space (resp., logic) is said to be complete precisely if it is Galois-closed. Two theorems are proven. A logic is complete if and only if it is reflexive and transitive. A valuation-space is complete if and only if it is closed under formation of super-valuations.     

Semantic Analysis of some Variants of Anderson-like Ontological Proofs

The aim of this paper is to prove strong completeness theorems for several Anderson-like variants of Gödels theory wrt. classes of modal structures, in which: (i). 1st order terms order receive only rigid extensions in the constant objectual 1st order domain; (ii). 2nd order terms receive non-rigid extensions in preselected world-relative objectual domains of 2nd order and rigid intensions in the constant conceptual 2nd order domain.