[Analytical Philosophy in the USA at the end of the 20th Century.].

Under the influence of Leibnitz in oposition to Kant, especially against his philosophy of mathematics, Bolzano analyses several topics discussed in analytic philosophy of today. His starting point is a distinction of concepts and intuitions, being two basic kinds of ideas-in-themselves, based on the postulates of nonemptiness, singularity and simplicity. This dichotomy is utilized in the analysis of conceptual and empirical sentences , the analytic/synthetic distinction and the a priori and a posteriori differentiation. His classification of analytic sentences, based on (...) his logic of variation and the degree of validity, in a narrow and broader sense corresponds to the contemporary view of analyticity for logical and linguistic reasons. Inspite of his ontological atomism he anticipates Quine´s holism according to which empirical sciences are theory-laden. He even accepts, at least for historical reasons, his empiricism concerning the role of observation sentences in theoretical sciences. According to Bolzano, no sharp demarcation between conceptual and empirical sciences can be drawn. (shrink)

Publikace nechce ani plnit požadavky kladené na učebnici, ani podat soustavu logiky. Chce však formulovat koncepci odpovídající soudobému stavu poznatků a založenou na vědeckém světovém názoru. Úvodem objasňuje populární formou základní termíny a některé logické teorie. Poté vykládá teorii deduktivních soustav a předmět logiky, kritizuje současné názory na logiku a její místo v soustavě věd a vymezuje její vztah k ostatním vědním oborům, zejména k filosofii. Závěrem klade otázku, jak lze aplikovat logiku v metodologii, technice a kybernetice.

[Philosophical Logic or the Philosophy of Logic?].

Is classical logic valid in empty domains? The aim of the paper is to show that for empty domains of individuals the thesis concerning the validity of classical logic cannot be consistently maintained. Taking the empty domain as an extension of a self-inconsistent property and making a distinction between logical and factual existence, it can be shown that in empty domains the assumption of the truth (resp.L-truth) of a universal statement leads to a paradox analogous to those of self-reflexivity.

Frege's linguistic views are exemplified by an analysis of the following topics: proper and common names, the definite and the indefinite article, the singular and plural distinction, words and sentences, together with the role of the copula, and the relationship of syntactical and semantical categories. His endeavour to overcome the ambiguities of natural language inherently connected with his logical investigations failed. In fact, his conceptions are relying on accidental features of a particular natural language, namely German. Therefore, they are neither (...) valid in general nor relevant from the logical point of view. They are influenced rather by his philosophical prejudices than by empirical results obtained in comparative philology and linguistics at all. (shrink)

Fregeś linguistic views are exemplified by an analysis of the following topics: proper and common names, the definite and the indefinite article, the singular and plural distinction, words and sentences, together with the role of the copula, and the relationship of syntactical and semantical categories. His endeavour to overcome the ambiguities of natural language inherently connected with his logical investigations failed. In fact, his conceptions are relying on accidental features of a particular natural language, namely German. Therefore, they are neither (...) valid in general nor relevant from the logical point of view. They are influenced rather by his philosophical prejudices than by empirical results obtained in comparative philology and linguistics at all. (shrink)