While the ‘grades’ of comparison is a familiar term, it is argued in this paper that a more thorough-going appreciation of a metaphor which originally had to do with steps allows us better to understand the development of the terminology of the grades of comparison as it moved from the Latin grammarians, especially Donatus and the commentators on his original work, into the medieval vernacular Irish and Welsh grammars. The architectural basis of the terminology, then, once identified, may help to clarify the use of such terms as Old Irish etargaire and how in Welsh grwndwal (lit.) ‘ground-wall’ came to be used of the positive form of the adjective