The programme of encompassing philology is a consciously structuralist one, based on the polarity between language as an abstract sign system and concrete texts, be they written or spoken, as sign formations. The meaning of a sign is described only by differences to other signs that are systeme-allowed. Linguistic signs of different size are recognised and taken into consideration, even a sentence is a sign. The sentence, central explanatory unit of the abstract system of language, is defined in full independence from then utterance, central explanatory unit of concrete texts.