The purpose of this paper is to present the Fitch's paradox. The reasoning similar to the Fitch's argument is applied to a concept of belief and thus some observations on the knowledge, beliefs and their boundaries are drawn. Interactions among completeness of knowledge, and of beliefs, omniscience and Fitch's theorem are examined. A few erroneous application of Fitch's argumentation or unsupported conclusion drawn from it are shown.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.