From at least as early as William Empson’s The Structure of Complex Words (1951), complexity has come to be viewed as one of the essential distinguishing factors of literary language. Empson’s study charts several examples of where a single word can communicate a ‘compacted doctrine’, through its various senses, its historical associations, and through the nuances and ambiguities that arise within the context of the broader linguistic unit (sentence, poetic line, etc.). Such features are not unique to literature (ordinary language of course also contains such complexity); yet insofar as they prove central rather than incidental to its operations, literature raises complexity to a new level. This general statement can also be interpreted in a diachronic manner: for the identification of complexity with literature becomes all the stronger from the modernist period, in which the perception that literature is especially or even uniquely ‘difficult’ becomes widespread. Empson’s own poems prove a representative modernist example, in this respect, accompanied as they are by pages of detailed explanatory notes.