  The Stoics had made a clear distinction between proper names and common nouns, listing them as different parts of speech, but while this possibility was recognized by Priscian and the influential twelfth century grammarian, Peter Helias, it was not adopted. According to Priscian, the nomen, the noun or name, is the first of the principal parts of speech, and it signifies substance with quality, that is, it signifies a thing of a certain sort, or an individual established in a certain nature. The nomen is divided into the common or appellative name and the proper name.  Because the proper name is a subdivision of the name, and hence a fully-fledged part of the language, it is taken to have the same semantic properties as the common name, and it can, indeed must, be taken to have a sense. According to Priscian, the proper name signifies a particular substance and its quality, and it may also include the apprehension of something common. Thus if I say ‘Virgil’, the common notions ‘man’ and ‘poet’ will be understood. Hence there are two kinds of senses attached to proper names, a particular sense which cannot be expressed by common notions, and an associated sense, a description.