This study critically examines previous approaches to textual criticism and editorship, and using the "Parzival" ms. Cgm 19 and the "Tristan" ms. Cgm51 develops the argument that every medieval version of a text possesses inherent value and represents the cultural knowledge of its age and that this can only be appreciated if divergent mss. are not simply seen as deficient variants of an 'original text'.Through an analysis of the historical contexts of text function, Baisch defines the origins, status, and function of textual variation in the medieval vernacular transmission of texts and provides a methodology for joining edition and interpretation.He sees textual criticism as a functional history of the transmission of medieval texts.The study makes an important contribution to the present lively debate on the principles of modern editorship and the medieval concept of text.