Several prominent Polish philosophers were nominalists. This paper concentrates mainly on the views of Leśniewski and Kotarbinski, in the belief that their views are the most interesting in themselves, the most historically important, and present most clearly the difficulties and challenges that nominalism has to face. But first, some terminological clarifications.

Nominalism in Poland

A description is made of the first steps taken towards the development of a model of epistemic beliefs, which is conceptually based on the learning process. In two studies, which were conducted in the domains of mathematics and physics, a quest was made to secure the first evidence of the usefulness of the model. The most important results of the studies were: (1) A questionnaire to assess epistemic beliefs could be developed and the factorial validity of this questionnaire could be confirmed. (2) Epistemic beliefs correlated in a meaningful manner with various variables. (3) Epistemic beliefs proved to be better predictors of scholastic achievement and scholastic motivation than IQ. Overall, a positive resume could be drawn for the first steps taken in the development of an Epistemic Learner Model.

First steps towards an epistemic learner model

The term ‘reism’ was introduced by Tadeusz Kotarbinski to denote the philosophical view that the category of things is the sole ontological category.1 Shortly after Elementy went in print, Kazimierz Twardowski pointed out in a letter to Kotarbinski, that a similar ontological theory has been elaborated by Franz Brentano in the last period of his life. In 1930, Kotarbinski delivered a lecture at 7th International Philosophical Congress in Oxford. After the congress, he received a letter from Georg Katkov with further information on Brentano’s reism.2

Reism in the Brentanist Tradition

Czeslaw Lejewski studied in Warsaw before the Second World War, after which he settled in England and resumed an academic career, becoming Professor of Philosophy in Manchester. His writings, all articles, continue and extend the ideas of his teachers, especially Stanislaw Leśniewski in logic and Tadeusz Kotarbinski in metaphysics.

Czesław Lejewski: Propagator of Lvov-Warsaw Ideas Abroad

When Russell argued for his ontological convictions, for instance that there are negative facts or that there are universals, he expressed himself in English. But Wittgenstein must have noticed that from the point of view of Russell's ideal language these ontological statements appear to be pseudo-propositions. He believed therefore that what these statements pretend to say, could not really be said but only shown. Carnap discovered a way out of this mutism: what in the material mode of speech of the object language looks like a pseudo-proposition can be translated into a perfectly meaningful proposition in the formal mode of speech (in the metalinguistic mode of speech of the logical syntax of language). But is this ascent into the metalanguage necessary? Taking advantage of Lesniewski's logical system there exists another way outwe can expand the number of categories of our ideal language. But Leśniewski's formulas raise another profound problem, the problem of “semantical muteness” (cf. W. G. Lycan ‘Semantic Competence and Funny Functors’ Monist
 64 (1979), 209–222).

C. Lejewski

Papers

Outline of an ontology