First, there is a question or direction. Which one is doing the interpretation? The critic, of course. He or she is the one who provides the metalanguage that makes sense of the infra-language of the text. Second, there is a question of size. The critic's vocabulary is enormously shorter than the text's repertoire. This is why the metalanguage mav be said to explain something. With one word in the critic's repertoire, for instance 'Oedipus' complex', you can explain four dozen novels and five hundred plays. Third, there is a question of precedence or of mastery. Who dominates the other? Answer: the commentator. Critics are much stronger than the text they dominate and explain, establish and analyse.
The mastery is so complete, Serres argues, that the texts, the novels, the plays, the myths, slowly disappear, buried beneath stronger and more powerful commentaries.