This paper contains a logic enabling us to reason in the presence of vague- ness phenomena. We consider an epistemological vagueness of concepts caused by the unavailability of total information about a continuous world which we describe in observational terms. Lack of information is manifested by the existence of borderline cases for concepts. Since we are unable to perceive concepts exactly, we cannot establish a sharp boundary between an extension of a concept and its complement. Some results for reasoning about (...) vague concepts are already known in the literature [1], [2], [3], [4], [10]. Usually, a semantics of vague concepts is developed within the theory of fuzzy sets or the theory of supertruth [9]. Following the idea that reasoning about vague concepts requires a special logic, we introduce a propositional language with sentential operators en- abling us to dene positive, negative, and borderline regions of any vague concept. A semantics of the language is rened within a framework of the theory of rough sets . The admitted semantics provides means for dening extensions of concepts in a formal way. We show that these extensions re ect properly our intuition connected with vagueness. For ex- ample, the law of excluded middle is not valid on the level of extensions. Moreover, for any concept, the extensions of formulas representing its pos- itive, negative, and borderline regions provide a partition of a universe of discourse. (shrink)

One of the generalizations of R. W´ojcicki’s concept of referential matrix is so-called pseudo-referential matrix . G. Malinowski, who introduced that concept, also considers a particular case of pseudo-referential matrices called discrete pseudo-referential matrices . In this note we want to show how any generalized matrix determines a semantically equivalent discrete pseudo-referential matrix.

In this paper a unified framework for dealing with a broad family of propositional multimodal logics is developed. The key tools for presentation of the logics are the notions of closure relation operation and monotonous relation operation. The two classes of logics: FiRe-logics (finitely reducible logics) and LaFiRe-logics (FiRe-logics with local agreement of accessibility relations) are introduced within the proposed framework. Further classes of logics can be handled indirectly by means of suitable translations. It is shown that the logics from (...) these classes have the finite model property with respect to the class of -formulae, i.e. each -formula has a -model iff it has a finite -model. Roughly speaking, a -formula is logically equivalent to a formula in negative normal form without occurrences of modal operators with necessity force. In the proof we introduce a substantial modification of Claudio Cerrato's filtration technique that has been originally designed for graded modal logics. The main core of the proof consists in building adequate restrictions of models while preserving the semantics of the operators used to build terms indexing the modal operators. (shrink)

In this paper a unified framework for dealing with a broad family of propositional multimodal logics is developed. The key tools for presentation of the logics are the notions of closure relation operation and monotonous relation operation. The two classes of logics: FiRe-logics (finitely reducible logics) and LaFiRe-logics (FiRe-logics with local agreement of accessibility relations) are introduced within the proposed framework. Further classes of logics can be handled indirectly by means of suitable translations. It is shown that the logics from (...) these classes have the finite model property with respect to the class of ♦-formulae, i.e. each ♦-formula has a ℒ-model iff it has a finite ℒ-model. Roughly speaking, a ♦-formula is logically equivalent to a formula in negative normal form without occurrences of modal operators with necessity force. In the proof we introduce a substantial modification of Claudio Cerrato's filtration technique that has been originally designed for graded modal logics. The main core of the proof consists in building adequate restrictions of models while preserving the semantics of the operators used to build terms indexing the modal operators. (shrink)

The foundation of the Christian counselling movement -- Christian counselling in the UK -- The aims of Christian counselling -- Integrating psychological and biblical truth -- Sigmund Freud--the founding father of psychotherapy -- The individual psychology of Alfred Adler -- Abraham Maslow--the man with new age tendencies -- Carl Rogers--a man who believed in himself -- Albert Ellis--the aggressive atheist -- The Bible's verdict on psychological 'truth' -- The case against Larry Crabb -- Self-esteem: the secular foundation -- Self-esteem and (...) the Christian counselling movement -- Self-esteem dogma in the light of scripture. (shrink)

In 'Een handvol filosofen' staan de filosofen centraal die sinds de oprichting van de Vrije Universiteit in 1880 aan deze instelling verbonden zijn geweest. Het gaat hierbij niet alleen om de inhoud van hun werk, maar ook om de personen zelf. Er waren filosofiedocenten die zich met de universiteit identificeerden en zich volledig konden ontplooien. Er waren er echter ook voor wie dit niet gold, die geïsoleerd of in gewetensnood raakten. Veel filosofiestudenten waren actief betrokken bij wat er in hun (...) faculteit gebeurde. Zij namen initiatieven, protesteerden soms tegen de gang van zaken en kozen partij in conflictsituaties. Sinds het eind van de jaren zestig van de twintigste eeuw verloor de Vrije Universiteit geleidelijk haar christelijk karakter. Tegenwoordig werken alle stafleden vanuit hun eigen motivatie mee aan een hoofdzakelijk seculier geworden universiteit, die ruimte biedt voor religieuze en levensbeschouwelijke diversiteit. (shrink)

One staple of living in our information society is having access to the web. Web-connected devices interpret our queries and retrieve information from the web in response. Today’s web devices even purport to answer our queries directly without requiring us to comb through search results in order to find the information we want. How do we know whether a web device is trustworthy? One way to know is to learn why the device is trustworthy by inspecting its inner workings, 156–170 (...) 1995; Humphreys 2004, Episteme, 6, 221–229 2009). But ordinary users of web devices cannot inspect their inner workings because of their scale, complexity, and the corporate secrecy which enshrouds both the procedures by which the devices operate and the companies that make them. Further piling on this predicament, authors have criticized web technology on the grounds that the invisibility of the web devices’ inner workings prevents users from critically assessing the procedures that produce a given output, in some cases, barring users from fulfilling their epistemic responsibilities, 343–355 2010; Miller and Record Episteme, 10, 117–134 2013). I consider four broad kinds of reasons which we can acquire without inspecting the inner workings of black-boxed technology: individual understanding, expert testimony, testing through experience, and social vetting; and show how each is a viable method of appraising black-boxed technology. By deploying these methods, we can remain responsible inquirers while nonetheless benefitting from today’s epistemic resources on the web. (shrink)