Interrogating the much-cherished concept of "poetic thinking," this book focusses on what interview and draft materials reveal of how poets think while in the act of writing. With findings from the cognitive tradition, this book uses performance theory and philosophy to examine this brief, creative window of conscious attention. Suddenness and the Composition of Poetic Thought draws out the implications of this radically curtailed view of consciousness on the poems and other texts we compose. Henrich von Kleist's assertion that "it is not we, but a certain condition of ours which knows" emerges as central to this analysis of the thinking we perform in the very moments of composition. Employing an extensive archive of interview materials with major Anglophone poets, discussing how they think in the moments of composition, the book also provides a lucid account of the links between poetic composition and live performative thinking in the context of the early (pre)textual history of the Ancient Greeks. A transdisciplinary study at the crossroads of philosophy, cognitive psychology, literary studies and linguistics, this book reconceptualizes the wellsprings of new thought in poems and advances our understanding of thinking's complex but vital link to the moment of utterance.