Three contributions to the two-valued propositional calculus

Summary Three chapters contain the results independent of each other. In the first chapter I present a set of axioms for the propositional calculus which are shorter than the ones known so far, in the second one I give a method of defining all ternary connectives, in the third one, I prove that the probability of propositional functions is preserved under reversible substitutions. This paper appeard orginally under the title “Trois contributions an calcul des propositions bivalent” inStudia Societatis Scientiarum Torunensis, Toruń, Polonia, Sectio A, vol. I (1948), pp. 3–15.     

Concerning axiomatizability of the quasivariety generated by a finite Heyting or topological Boolean algebra

In classes of algebras such as lattices, groups, and rings, there are finite algebras which individually generate quasivarieties which are not finitely axiomatizable (see [2], [3], [8]). We show here that this kind of algebras also exist in Heyting algebras as well as in topological Boolean algebras. Moreover, we show that the lattice join of two finitely axiomatizable quasivarieties, each generated by a finite Heyting or topological Boolean algebra, respectively, need not be finitely axiomatizable. Finally, we solve problem 4 asked in Rautenberg [10].     

Systemy S4 I S5 Lewisa a spójnik identyczności

Allatum est die 28 Septembris 1970     

O klasach normalnych i nienormalnych na terenie języka potocznego

Problematyka i glówne tezy tej pracy pochodz od pierwszego autora. Udzial drugiego autora sprowadza sie do propozycji utosamienia jeezyka potocznego z formalizmem logiki zda i logiki nazw oraz do pewnych sugestii odnonie systematyzacji materialuAllatum est die 2 Octobris 1965     

Józef Tischner’s epistemology of “political reason” and the “ethics of truth”

Studies in East European Thought - That which connects ethics and epistemology is the concept of truth. The threads concerned with the ethical and epistemological understanding of truth are...