Poetry Realized in Nature shows Coleridge’s method at work and, more generally, explores German philosophical science, Naturphilosophie, and the relations between science and romantic thought. It combines a biographical approach with intellectual history, reconstructing Coleridge’s imaginative enterprise across the whole range of the physical and life sciences. Coleridge strove for coherence in all realms of thought, and so the ways in which he explored scientific ideas illuminate all aspects of his inquiring spirit. He sought self-knowledge, which required a knowledge of man and mind in relation to nature and God. There was, accordingly, an intimate relationship between his theology and philosophy, and his ideas about the natural world. Science functioned as a touchstone in his philosophy, thus indirectly reinforcing his theology. The ideas he derived from science also bore directly on his critical doctrines, including the theory of imagination.