In the initial part of the article texts of some authors are analyzed concerning material implication. In the further part of the article the proposition is justified that the operator of material implication differs in quality from other truth-functional operators. The final part of the article is devoted to considerations aiming at presenting what the thesis of the classical propositional calculus, in which the main operator is the operator of material implication, denote.

The first part of the paper_ outlines the development of causality in Greek philosophy. Some remarks are made on how some medieval philosophers approached to the problem. The paper shows also how modern philosophy understood causation. The paper inquires into the characteristics of causal relation as it is accepted in the domain of modern and recent physics. In the second part of the paper one finds some remarks concerning the programme of construing a new system CI of logic of causal (...) propositions. This system is adequate to the manner in which causality is presented in physics. The system CI is being construed to characterize the connective of relativistic conditionals ‘$\rightsquigarrow$’ by means of the methods of recent logic. This connective should be read as follows: ‘if …, then for that reason …’. The arguments of the connective ‘$\rightsquigarrow$’ may be propositional formulas describing a particular event. The new system of non-classical logic is based on the classical propositional calculus, on the one of systems of temporal logic, and on a system ZI of logic of change. The findings concerning causation, as outlined in the first part of the paper, constitute descriptive semantics of the system CI presented in the second part of the paper. This system may play a positive role in the indirect justification of theorems in philosophy in a broad sense. (shrink)

In der Einleitung zu diesem Artikel wurde betont, dass die in der Philosophie geäusserten Feststellungen zur Veränderung ein prinzipielles Schema abstecken, in dessen Rahmen detail- lierte naturwissenschaftliche Forschungen unternommen wurden. In den einzelnen Teilen der Arbeit werden die hauptsächlichen philosophischen Konzeptionen der Veränderung charakterisiert. Analysiert werden Aristoteles Ansichten zur Veränderung, der im Altertum den Gegensatz von Statismus und Variabilismus überwand. Nicht übergangen werden durfte die Konzeption der Veränderung des neuzeitlichen Philosophen G. W. F. Hegel, der ohne Berücksichtigung der Empirie das (...) Wesen des Seins ais völlig logisch und evolutionär ansah. Auch die Ansichten zur Veränderung des französischen Philosophen H. Bergson werden dargelegt, der zu einer Zeit, ais die szientistische Haltung dominierte, das Bedürfnis nach einem anderen, tieferen ais die mathematische Naturwissenschaft Typ des Wissens ausdrückte. Auch A. N. Whiteheads Ansichten zu der uns interessierenden Frage werden erwähnt. Auf dem Hintergrund dieser Ansichten wurde die Tatsache der Veränderung auf gez igt, von der die die zeitgenössische Naturwissenschaft krönende Physik spricht. Es wurde auch kurz versucht, die Frage der Veränderung im Zusammenhang mit dem für die Physik noch grundlegenderen Begriff der Zeit zu beleuchten. Die im vorliegenden Artikel unternommenen Analysen können ein Hauptelement der beschreibenden Semantik fiir die Systeme der Logik der Veränderung sein, welche zu konstruieren sind bzw. deren Erkenntniswert - bei schon konstruierten Systemen - einzuschätzen ist. (shrink)

Starting from the 1930s logicians tackled problems connected with applicability of logic in natural sciences and in many cases they tried to practically apply logic in these sciences. In the article entitled \'Logicians and logic on study of nature\' it is stressed that the broadly understood formal logic supplies natural sciences, and especially physics, with a paradigm for a method of ordering theses. It is also shown what application of logic laws to natural sciences consists in, and theses are formulated (...) concerning what the laws of classical prepositional calculus state. A lot of attention is devoted to the language of modern and contemporary physics. Modern and contemporary physics uses two languages, i.e. the mathematical language and the so-called notional language. The logic of the former language is classical logical calculus. In connection with the notional language logicians construed a lot of systems of non-classical logics in which laws are given that govern the correct use of non-extensional operators connected with such terms occurring in natural sciences as \"time\", \"cause\", \"change\" etc. The language of well construed systems of non- classical logics may serve saving, storing and precise communicating the results obtained on the ground of natural sciences. (shrink)

The first part of the paper shows two types of the systems of contemporary logic placed in one of J. Bocheński’s works. The second part of the paper contains Bocheński’s theses concerning contemporary logic. They have been shown against the backdrop of the views held by other authors who discussed some kin issues. In order to supplement Bocheński’s considerations a division of functors has been added. They are divided into extensional and non-extensional. Much attention has been devoted to the problems (...) of logical constants that is rarely discussed in learned literature. It has been stressed that at least one of Bocheński’s typologies should basically be changed, having taken into account the remarks in the paper that supplement Bocheński’s analyses. The above issues have been discussed against the backdrop of the question of relations that obtain between contemporary logic, mathematics, and philosophy. (shrink)

The paper appreciates six conditions which, according to G.E. Hughes and M.J. Cresswell, must be respected by those formal systems which aspire to be systems of modal logic. There are few such systems. The sense of modal functors \"it is necessary that,\" \"it is possible that,\" in this type of systems is in no way made precise. The paper undermines the validity of some conditions shown by Hughes and Cresswell. It outlines the way by which to construct a system of (...) modal logic in which the functor of logical necessity and logical possibility would be unambiguously characterised by methods of contemporary logic. (shrink)