Mutual Implications: Otherness in Theory and John Berryman's Poetry of Loss examines how a dialogue between poetry and critical theory can disrupt our expectations on how we read theory and interpret poetry. Instead of viewing theory as the object and poetry as the subject of study, this thesis focuses on the otherness of both poetical and theoretical language, that is, what remains unaccounted for in each mode of language. By problematizing the idea of poetical and theoretical origins, the thesis aims at providing a space in which mutual implications between Berryman's poetry of loss and four different theoretical perspectives can be generated. The poems mainly analysed are Berryman's "The Ball Poem," Homage to Mistress Bradstreet, and The Dream Songs, and the theoretical perspectives are Martin Heidegger's thinking concerning the word and the concept departure, David S- Reynolds's notion of the subversive in the American Renaissance, Nicolas Abraham's psychoanalytical concept anasemia, and Maurice Blanchot's theory of death and poetry in his book The Space of Literature. On a more general level, the purpose of the thesis is to create a space for Berryman's poetry within critical theory and at the same time provide a place for theory within Berryman studies.