This study examines Wallace Stevens' ideas and practice of poetic language with a focus on the 1930s, an era in which Stevens persistently thematized a keenly felt pressure for the possible social involvement and political utility of poetic language. The argument suggests how mutually implicated elements of his poetry such as diction, prosody and metaphor are relied on to signify or enact aesthetic closure; both in the negative terms of expressive impotence and unethical isolation and the positive ones of imaginative and linguistic change. In this respect, the study deals closely with the epistemologically and ethically fraught issue of the ambiguous and volatile role of non-semantic elements and linguistic difficulty in Stevens' language. Assuming that these facets are not exclusive to this period but receive a very clear, and therefore instructive, formulation in it, the discussion outlines some of Stevens' most central tropes for poetic creativity at this stage of his career, suggesting ways in which they came to form part of his later discourse on poetic functionality, when polemical concepts for the imagination, such as "evasion" and "escapism," became central. Stevens' prosody is discussed from within an eclectic analytical framework in which cumulative rhythmics is complemented by traditional metrics as a way of doing justice to his rich, varied and cognitively volatile use of verse language. The expressive potency of prosodic patterning is understood both as an effect of its resistance to semantic interpretation and by assuming a formal drive to interpret them in relation to the semantic and metaphoric staging of individual poems. A poem, in turn, is understood both as a strategic, stylistically deviant response to the challenges of a particular historical moment, and as an attempt to communicate through creating a sense of linguistic resistance and otherness.