Jan Wolenski

The author opposes two kinds of rationalism to irrationalism. The first kind of rationalism, approved by the author, considers as rational these cognitive procedures that can be communicated and verified intersubjectively. The author calls this view – after K. Ajdukiewicz – anti-irrationalism. On the other hand, irrationalism is a position that negates the need of ability to communicate intersubjectively and to verify cognitive procedures. The views of mystics or of H. Bergson could be an example of irrationalism. The second kind of irrationalism is apriorism, i.e. the position that ascribes certainty to cognitive results achieved by intuition. Data coming from intuition are not intersubjectively communicable, intersubjectively verified and they are not subject to falsification, hence the second kind of rationalism, i.e. apriorism, is in fact irrationalism. Phenomenology, stressing the importance of apriori cognition, would then have many things in common with irrationalism.

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

The theory of double truth was proposed in the Middle Age by Latin Averroists as a solution of how the relation between faith (religion, theology) and reason (science) should be conceived. In general terms, according to this theory, there are two orders, one dictated by faith and second dictated by reason. Both are epistemologically different and cannot mutually remain in logical relations such as (in)consistency or entailment. This view was used in the Middle Ages for defending science against a claim that it is the ancilla thelogiae only. The author compares the theory of double truth with other solutions like the model of identity of science and theology or the model of two overlapping regions (Thomas Aquinas). It is argued that the substantial difference of the language of faith and the language of reason makes logical relations between statements of science and statements of theology impossible. In particular, all cosmological proofs of God's existence as well as projects of intelligent design fail if the theory of double truth is adopted

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

Traces of the coherence theory are to be found in rationalistic epistemological systems of Leibniz, Spinoza, Kant, Hegel and Fichte. However, the first fully advanced coherence theory was proposed by Bradley in XIX century. He was followed by Joachim, McTaggart, and particularly Blanshard and Ewing. The coherence theory later became popular among philosophers of the Vienna Circle, notably in Neurath and Hempel.2 Recently, Rescher tried to combine various proposals of coherentists into one fully unified view.