Two formal types of models of living processes, especially evolutionary ones, may be distinguished: the well-known mathematical type and the less-known logical one. The latter applies the terms “class” or “set”; both the terms are understood either in a collective sense (in mereology) or in a distributive sense (in set theory). These formal terms may be used among others to such organic multiplicities as populations or species of organisms, and to organic constituents (molecules, cells, organs) of living organism. Collective concepts refer to objects existing in nature, whereas distributive concepts refer to the linguistic and research constructions of models of natural objects, developed to cognitively grasp natural regularities.

The early philosophical standpoint of Professor Bogusław Wolniewicz alluded mainly to the so-called first philosophy of Ludwig Wittgenstein, as expressed in his Tractatus Logico-Philosophicus. Professor Wolniewicz’s views have found their expressions, first, in the book (in Polish) Things and Facts. An introduction to the first philosophy of Ludwig Wittgenstein (1968), and finally in his monograph (in Polish) Ontology of Situations. Foundations and Applications (1985). In both cases, Wolniewicz’ standpoint has been expressed by giving a substantive interpretation to semiotical and logical concepts (i.e. by producing hypostases). This practice looks rather dubious to me, in both cases, although I hope that ontology of situations can be usefully treated as a general formal theory of semantical correlates characteristic for sentential statements.