  Roger Bacon is probably the most important medieval theorist of sign — at least he is the author of the most extensive medieval tract on signs known so  far.[21]  Starting from a minute analysis of the notion of sign and its various divisions, Bacon develops both in De signis (ca. 1267) and in his Compendium studii theologiae (1292) a general conception of signification as well as a detailed theory of the linguistic sign, so that here, as in Augustine, semantics is integrated into a broader theory of sign in general. According to Bacon, the concept of sign belongs to the category of relation. To be more precise, a sign, as it was pointed out already in Augustine's definition, is a triadic relation, such that it is — in principle — a sign of something to someone. This way of putting the point, however, gives rise to the question of whether both relata of this relation are equally essential for its existence. What would happen if one of these relata did not exist? What if the designated thing ceased to exist? And what if there were no cognitive power taking notice or even being able to take notice of the sign?