The article deals with the syntactic section in constructing propositional epistemic logic and it draws on the source of the so-called Finnish school of logic (K. J. J. Hintikka, I. Niiniluoto, V. Rantala and others). The author tries to show that construction of such logic is justified for the analysis of philosophical problems as well as for the wider interdisciplinary application. The article also points to possible ways of overcoming some of the difficulties inherent to such an approach.
