The paper deals with several problems concerning with notion of truth. The author is interested in logical aspects of the definition of truth given by Ajdukiewicz and Kotarbinski. He introduces the multimodal logical calculus with propositional quantifier and applies it to analysis of some formulations of the definition. The analysis is focused on two main formulations of the definition, namely on absolute and partial formulation. It is shown that the notion of truth specified by absolute formulation is unconstructive i.e. it (...) is possible to state that some utterance is true without stating any sentence which express the propositional content of the utterance. On the other hand after the partial formulation the notion of truth seems to have some counterintuitive features, for example the falsehood is no longer the same as the lack of truth. Moreover only the absolute approach leads to difficulties connected with the Liar Paradox. (shrink)

The article deals with philosophical issues concerning abstraction and concreteness, focusing on selected ontological and logical-ontological threads of this dif ficult and intricate problem. Thus, it will concern first of all abstract and concrete objects, and only then abstract representations and judgments and concrete representations and judgments. The subject of interest will also be the process of abstraction and the relations that take place between abstract objects such as features or relations, pure qualities, and ideal objects.