The main idea of this study is a principle of truth in fiction, the distance and the similarity between literature and reality, the definition of fiction, textual marks of artistic fiction, notions of “play” and “dream” in the definition of fiction. This fictional character of literature is required as an intrinsic quality. A literary work exceeds the categories of truth and lies; it is a mental structure able to absorb the truth and imaginary simultaneously. Fictionality is a convention that permits the text interpretation via aesthetic criteria (novelty, originality, authenticity) instead of the logical principle of truth. This is a demarcation between literature and the rest of the communicative process.