The paper presents seven nihilistic functional calculi (NFC), founded on nihilistic propositional calculi. NFC are characterized from the syntactic and semantic points of view. For each of NFC both points of view are proved to define the same sets of formulas.

From a formal point of view, the nihilistic propositional calculi, called in this text „npc”, are such propositional calculi that include three unary propositional conectives: T, F, ~, and one binary propositional connective ≡. They read respectively: true, false, untrue that, if and only if. Their theorems are, mong other things, such expressions as: Tp ≡ p, Fp ≡ ~p, with p being a propositional variable. The four npc are presented in this work, i.e. on two-valued, two three-valued, and one (...) four-valued. Moreover, two of them are also paraconsistent calculi. Npc are constructed by means of the axiomatic method. Following the presentation of npc axioms, the four so called n-algebras are introduced. The npc axioms are proved to be adequate to appropriate n-algebras, i.e. sets of theorems and tautologies of each npc are identical. (shrink)

An axiomatic theory of values is presented in this article. The basis of this theory is Czeżowski's idea of values.

Various arguments for and against principles of non-contradictions: ontological and logical are presented in this article. Two non-classical sentential calculi, in which logical principles of non-contradictions are not effective, are presented too.

In the article the formalization of a certain fragment of ontology is presented. The axiomatic definition of property and few definitions of the notion of existence are given. The opinion about two kinds of existence is asserted.

In this article the author solves the Ship of Theseus Paradox. He gives also the axiomatic definition of genidentity.

The Liar, Berry's, Richard's and Grellling's antinomies are presented and ana-lysed in this article. Three non-classical sentential calculi are presented, too. The author also discussed these calculi from the point of view of their application for the solutions of these antinomies.

In the article some known arguments against the principle of bivalence and the principle of excluded middle are recalled and examined. New arguments against the principle of contradiction are also presented.

Psychologists use identity’s and Ego’s conceptions. The first conception is not clear, the second one from logical point of view is not correct. The aim of this article is to provide the definition of these two conceptions.