The aim of my paper is to distinguish groups of semantic motivations that have become the basis for the formation of words or word associations expressing obviousness. The study covered various European languages with particular emphasis on the Slavic languages. On the basis of the research, the following groups were distinguished: 1) knowledge and understanding; 2) sight, perception and clearness; 3) talking and adjudication; 4) nature; norm and custom; 5) consequence; 6) confidence, trust and security.