The study approaches the question of the origin of idiomatic phrases from the point of view of classical rhetoric. After a detailed theoretical discussion of phenomena such as metaphor, metonymy, irony, antithesis, etc., some 400 German idiomatic phrases and sayings are subjected to close rhetorical/semantic examination. This empirical section of the study conveys a differentiated picture of the meaning structure of 'figurative' expressions, points up links between the literal and idiomatic meaning of such expressions, and shows the high and varied degree to which 'ornamental' rhetorical elements participate in the formation of idiomatic vocabulary units.