The author considers the issues of linguistic diversity (distribution of variation within communities) and linguistic distance (degree of variation between varieties within a system or between variety systems). He seeks to emphasize the usefulness for further development of distance studies of the concept of language area (Sprachbund), the necessity of its extension to include non-langue components of communicative systems, and the necessity to consider various types of constraints on distance. The author also proposes the concepts of linguistic union and communicative style. (Author/VM)