This dissertation asks how the physiological conception of the mind promoted by scientific, philosophical and cultural forces since the mid-twentieth century has affected poetic accounts of mental experience. For the cohort of poets I identify here—James Merrill, Robert Creeley, A.R. Ammons, John Ashbery, and Jorie Graham—recognition that fallible, biological mechanisms determine the very structure of human subjectivity causes deep anxiety about how we perceive the world, exercise reason, and produce knowledge. These poets feel caught between the brain sciences’ empirical vision of the mind, which holds the appeal of a fresh and credible vocabulary but often appears reductive, and the literary tradition’s overwhelmingly transcendental vision of the mind, which bears intuitive resonance but also appears increasingly naïve. These poets find aesthetic opportunity in confronting the nature of mind: Merrill takes up forgetting as a central subject, making elegant, entropic monuments out of the distortions and perforations of embodied memory; Ammons and Creeley become captivated by the motion of thinking, and use innovative, dynamic forms to emphasize the temporal and spatial impositions of embodiment upon the motions of thought; Ashbery luxuriates in the representational possibilities of distraction as a structural and thematic principle; Graham identifies the anatomical limits of the visual system with our limits of empathetic perspective, conceiving of her poems as prostheses that can enhance our feeble power to imagine other minds. In a host of significatory practices that reimagine lyric subjectivity in physiological terms, these poets’ ambitious and influential oeuvres reveal the convergence of “raw” and “cooked” post-war poetries in a set of fundamental suppositions about our aptitudes as observers, knowers, and interpreters; this convergence exposes the vestiges of the Romantic mind in modernism’s empowered conception of the poetic imagination. Uniquely equipped to explore meaningful correspondences between physiological and literary form, the contemporary lyric defies the novel’s preeminent position in the study of literary consciousness by demonstrating an enterprising talent for philosophical investigation of the experience of mind.