Jan Wolenski

This paper is devoted to analysis of co-called paradox of confirmation formulated by C. G. Hempel in the 1930s. In particular, the author proposes a solution of this puzzle. The proposal consists in refining the concept of confirmation by adding a clause that if A confirms a hypothesis h, the former must be a logical consequence of a latter, eventually derived with the help of additional assumptions. This leads to an additional constraint requiring that confirmations act relatively to sets of reference. Finally, if h and h’ are logically equivalent, a sentence A confirms both to the same degree if and only if related sets of reference are the same

Ancien etudiant de Brentano et de Zimmerman, Kazimierz Twardowski, apres son election a la chaire de philosophie a Lvov en 1895, crea autour de lui un cercle d'etudiants et de collaborateurs exceptionnel, connu aujourd'hui sous le nom d'Ecole de Lvov-Varsovie. A mi-chemin entre Vienne et Cambridge, c'est a Lvov, et puis partiellement a Varsovie, que Jan Lukasiewicz, Stanislaw Lesniewski, Alfred Tarski, Kazimierz Ajdukiewicz, Tadeusz Kotarbinski et bien d'autres encore, repenserent dans un esprit d'analyse les questions fondamentales de la philosophie du langage, de la logique, de la philosophie des sciences et des mathematiques. Plus qu'une simple traduction, ce livre est une version revisee de la monographie desormais classique que Jan Wolenski, connu pour ses travaux non seulement en histoire de la philosophie analytique, mais aussi en epistemologie et en theorie de la verite, a consacree a l'Ecole de Lvov-Varsovie.

This paper argues that science is not dependent on philosophical assumption and does not entail philosophical consequences. The concept of dependence and entailment is understood logically, that is, are defined via consequence operation. Speaking more colloquially, the derivation of scientific theorems does not use philosophical statements as premises and one cannot derive philosophical theses from scientific assertions. This does not mean that science and philosophy are completely separated. In particular, sciences leads to some philosophical insights, but it must be preceded by a hermeneutical interpretation

This papers discuss the place, if any, of Convention T (the condition of material adequacy of the proper definition of truth formulated by Tarski) in the truth-makers account offered by Kevin Mulligan, Peter Simons and Barry Smith. It is argued that although Tarski’s requirement seems entirely acceptable in the frameworks of truth-makers theories for the first-sight, several doubts arise under a closer inspection. In particular, T-biconditionals have no clear meaning as sentences about truth-makers. Thus, truth-makers theory cannot be considered as the semantic theory of truth enriched by metaphysical (ontological) data. The problem of truth-makers for sentences about future events is discussed at the end of the paper.

This paper examines some problems concerning modalities as operators acting on sentential arguments. At first, formal dependencies between modalities are described. Then, the problem of translations of modalities as operators into modalities as predicates is discussed. The author shows that although some predicates satisfy laws of the logical square for modalities, they cannot be represented by sentences with modal operators in front. The explanation of this fact is proposed by using Czeżowski\'s idea of modi entis and the content of presentations

The paper consists of two parts. The first contains the paradox of Truth-teller, i.e. a sentence which asserts own truth. The paradox appears when we apply logic of rejection to the Truth-teller sentence. The Truth-teller paradox is symmetric with respect to the Liar paradox. The second part considers a sentence which asserts own provability. This sentence is unprovable on the base of rejection logic. This leads to counterparts of the Gödel incompleteness theorems and other metamathematical results

.  This papers examines formal properties of logical squares and their generalizations in the form of hexagons and octagons. Then, several applications of these constructions in philosophical analysis are elaborated. They concern contingency (accidentality), possibility, permission, axiological concepts (bonum and malum), the generalized Hume thesis (deontic and epistemic modalities), determinism, truth and consistency (in various senses. It is shown that relations between notions used in various branches of philosophy fall into the same formal scheme.