Regardless of the approach one uses in the study of translating and translations, it remains necessary to delimit the legitimate field of concern. I.e. translations must be identified and described sui generis as the results of a text-processing activity. From the linguistic and text-theoretical perspective this objective is fulfilled by the concept of equivalence; a translation is defined as a secondary text that stands in an equivalence relation to the primary text. The range of the equivalence-oriented approach and the possibilities it offers for systematic description and explanation of translational phenomena are, however, limited. Its problems and limitations become apparent not only in the context of historical translation research, but also whenever interest focuses upon the text-productive – i.e. ultimately creative – aspect of translation, as opposed to its reproductive aspect, i.e. the linguistic-textual relationships between languages and texts as these are deduced from regularities.