Abstract
Choosing two thinkers from two entirely different periods of the history of philosophy, the article illustrates the issue of the most general conditions of truthful speech, which take effect on the crossroad of the narrowly conceived semantics and a broadly construed concept of the world as a concept that implies the posting of neat limits of the meaningful linguistic articulation of what there is. From this very general issue, the article turns to the narrower question of negation, and thus of the rules of the use of the correct and sometimes true speech that, nevertheless, lacks its specific referent in the full structure of reality.