This paper outlines an approach to the principle of bivalence based on very general, but still elementary, semantic considerations. The principle of bivalence states that (a) “every sentence is either true or false”. Clearly, some logics are bivalent while others are not. A more general formulation of (a) uses the concept of designated and non-designated logical values and is captured by (b) “every sentence is either designated or non-designated”. Yet this formulation seems trivial, because the concept of non-designated value is (...) negative. In order to refine the analysis, the class of anti-designated values has been distinguished. The non-trivial version of the principle of bivalence is expressed by (c) “every sentence is either designated or anti-designated”. The last part of the paper mentions some extralogical reasons for considering the principle of bivalence with truth being a designated value as intimately connected to human thinking and behavior. (shrink)
Józef M. Bocheński began his philosophical career as an eclectic philosopher, then switched to Thomism and finally became a representative of the analytic school. As a Thomist he wanted to reform this orientation by the resources of modern formal logic. This tendency culminated in the establishment of the Cracow Circle (established in 1936) whose members were Bocheński, Jan F. Drewnowski, Jan Salamucha, and Bolesław Sobociński. However, the program of the Cracow Circle was rejected by most Thomists who considered traditional logic (...) as an entirely sufficient device of philosophy. Bocheński was very disappointed by this attitude of his Thomist fellows. His evolution toward analytic philosophy, free of any ideological pressure, can be regarded as his reaction to the conservatism of Thomism. (shrink)
This paper discusses the distinctions indicated in its title. It is argued that the distinction between syntax and semantics is much more important for the present situation in logic than other distinctions. In particular, doing formal syntax and formal semantics requires the use of an informal melanguage based on ordinary mathematics.
This paper examines the problem of genesis of logic in the light of naturalism as a philosophical view about the nature of knowledge and reality. The main difficulty of naturalism as far as applied to logic consists in reconciling genetic empiricism (all cognition starts with experience) and abstract nature of logic. Anti-naturalism (Platonism, for example) maintains than empiricism is not able to explain how logical theorems as a priori assertions are accumulated. To defend naturalism one should note that experiential character (...) of knowledge can be understood phylogenetically or ontogenetically. The former account is more suitable for naturalism and allows us to investigate genesis of logic by glasses of evolutionary theory. This way can be supplemented by an appeal to genetics. Both theories can explain how logical competence, that is ability to use deduction, arose in humans. The author claims that the structure of the genetic coded has some properties that became transformed into logical rule. Some analogies between consequence operation and topological closure are employed in analysis. (shrink)
For decades Ryszard Wójcicki has been a highly influential scholar in the community of logicians and philosophers. Our aim is to outline and comment on some essential issues on logic, methodology of science and semantics as seen from the perspective of distinguished contributions of Wójcicki to these areas of philosophical investigations.
This paper comments Susan Haack’s remarks about Twardowski’s criticism of relativism in the theory of truth. The author summarizes Twardowski’s arguments for truth-absolutism and tries to show that that their presentation by Haack is incomplete. The defense of Twardowski’s position in the paper uses ideas developed by Tarski and Kokoszyñska.
Roman Ingarden offered a strong criticism of the verifiability principle in his talk delivered at the 8th International Congress in Prague in 1934. Ingarden argued that this principle either violates itself or smuggles a hidden sense. In this paper I show that Ingarden-like arguments about smuggled (but this pejorative qualification is skipped) meaning apply not only to the criteria of sense, but also to other semantic assertions within language-hierarchies in Tarski’s sense.
This paper investigates relations between truth and consistency. The basic intuition is that truth implies consistency, but the reverse dependence fails. However, this simple account leads to some troubles, due to some metalogical results, in particular the Gödel-Malcev completeness theorem. Thus, a more advanced analysis is required. This is done by employing the concept of ω-consistency and ω-inconsistency. Both concepts motivate that the concept of the standard truth should be introduced as well. The results are illustrated by an interpretation of (...) the well-known logical square and its generalization. (shrink)
This volume portrays the Polish or Lvov-Warsaw School, one of the most influential schools in analytic philosophy, which, as discussed in the thorough introduction, presented an alternative working picture of the unity of science.
. 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.
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. (shrink)