This dissertation examines the pivotal function of animals in modernist writing, particularly where modernist style confronts inherited moral codes. Classic accounts of modernism emphasize "impersonality" as the prime method for artists seeking cultural and ethical authority in the period after 1880. This project digs into what I argue is ultimately the more palatable capacity of literary beasts to animate a similar poetics of authority. Where doctrines of impersonality often resorted to figures of the inorganic in order to simultaneously disavow and indulge the expression of authorial intention, modernists such as Gerard Manley Hopkins, Virginia Woolf, James Joyce, Rudyard Kipling, and Marianne Moore instead avowed their didactic ambitions by appealing not to traditional expressive and explicit methods nor, on the other hand, to the complete evacuation of personality, but to the vitality and instinct of animals. More than any platinum filament (T.S. Eliot's famous catalyst), animals offered modernists a vocabulary for the bodily and behavioral mechanisms by which individuals become ethical and historical subjects. In my chapters, I examine specific formal effects that require animal energy from the modeling of queer poetic virtuosities upon animal instinct (as in Hopkins windhover, for example, or Moore's slapstick critters) and the casting of fictional characters along evolutionary-typological lines (as in Woolf's The Waves) to the anticolonial implementation, even, of a "bestial" prose style resistant to modernism's self-authorization (exemplified by the indifferent creatures we find in Finnegans Wake).