Jan Wolenski

Formal semantics is understood either as a formal analysis of semantical features of natural language or as model-theoretic semantics of formal(ized) languages. This paper focuses on the second understanding. The problem is how to identify the formal aspects of formal semantics, if we understand ‘formal’ as ‘independent of content’. This is done by showing that the form of semantical interpretation of a language L is given by its syntax and the parallelism of the signature of L and its interpretative structure SI. However, the content of interpretation, that is, the way of correlating of L-expressions with extralinguistic items depends of informal factors. The discussion shows that semantics is prior to syntax

Kazimierz Twardowski is most commonly known as the teacher of great philosophers and the founder of the Lvov-Warsaw School. As a philosopher however, he is primarily remembered for his famous comparison of the contents and objects of various kinds of representations, a comparison that remains enshrined in European thought.In fact, he attained important results in many other branches of philosophy as well. For instance, in ontology, he laid the foundations for the modern theory of formal structure of objects, and he introduced the theoretically fruitful pair of terms, action-product. In epistemology, he developed a profound analysis of the notion and criteria of truth; and he provided a forceful account of the errors underlying relativist theories of truth. In methodology, he drew an explicit distinction between the processes of discovering, systematising, and grounding in science, and he offered accurate descriptions of the nature of psychology and other humanities. In logic, he offered decisive arguments on behalf of the idiogenetic conception of judgement, and he improved the traditional typology of adjectives.These achievements are of significance that is not only historical. Kazimierz Twardowski's work, formulated in plain, precise language, are instructive and inspiring for contemporary students of philosophy.

This paper compares Kotarbiński’s reism and naturalism. It argues that basic ontological and epistemological reistic principles fit naturalism very well. In particular, the thesis claiming that there are only spatiotemporal things (bodies) gives a very simple naturalistic account of reality. Radical realism defended by Kotarbiński is a version of direct realism, a view about perception which is very accurate for naturalism. On the other hand, since difficulties of reism are also problems for naturalism, the former illuminates typical challenges for the latter

Metalogic (as a part of metamathematics) deals with the properties of formalised mathe- matical theories. Its applicability to empirical theories is an object of debate. The paper defends the moderate view that although it is difficult to expect such spectacular results, as have been obtained on mathematical theories, nevertheless the metalogical analysis of the first two gives us some benefits. Empirical theories may be understood as axiomatised sets of propositions closed with the operation of logical consequence. Two questions illustrate the thesis of this paper, namely the question of the elimination of theoretical terms and the question of the so- called philosophical presuppositions of science. As regards the second problem, a negative thesis is defended here: science is not based on philosophical presuppositions as premises of scientific reasonings