  A constitutive factor of the emergence of a medieval theory of signs within the context of grammar and logic is the resumption of Augustine's practice of embedding the concept of language into the generic notion of sign. Already Peter Abelard (1079–1142), in many respects the most important author of the 12th century, points out, that the phenomenon of linguistic signification (significatio vocum), falling into the sphere of competence of logic, does not cover the whole range of sign processes (Abelard: De dial., 1956: 111). For things in the broadest sense may function as signs, too, if they are connected to each other in such a way that the perception of one leads to the cognition of the other. This can be the case when the one thing is an image of the other, when things are either arbitrarily imposed to exercise the function of signifying (significandi officium), as for instance the famous circulus vini, a wreath of foliage, attached outside the tavern, indicating that wine is sold inside, or the conventional gestures of monastic sign  languages,[14]  or when two things, by being repeatedly noticed in conjunction, are customarily (secundum consuetudinem) associated with each other, or, finally, when they bear some sort of relationship to each other (secundum aliquam earum ad se  habitudinem).[15]