<p>This essay argues that early-nineteenth-century Romantic literature is defined by its relationship to the era’s growth of the modern disciplines which eventually gained prominence around the mid-nineteenth century. The analytical milieu in which newly formulated scientific disciplines gradually earned intellectual legitimacy stimulated the Romantic poets to pursue a place within the presiding body of knowledge. As Wordsworth claimed: “Poetry is the first and last of all knowledge” (“Preface” to Lyrical Ballads, 1802).</p><p>  I will discuss how Keats’s poems adapted the language derived from medical science as a reflection of the cross-fertilization of branches of knowledge, which was attainable only before the new consolidation of modern disciplines. Medical science in the early nineteenth century triumphed in its central emphasis on the brain and the nervous system, witnessing their mediation of exterior perception and sensual experience, and effectively envisaging the elegant networks of the body. At this point historically, the term “sympathy” in the medical sense — rather than the usual application of human fellow-feeling — signified harmoniously corresponding functions connecting the distant zones of the body. Keats’s poetry in this extended conception of “sympathy” dynamically expands the range of textual interpretations, as in Endymion, where love and friendship — the close ties which unite human beings — are reconfigured as “sympathetic communication” between living creatures through the physically organized network of sensation. </p><p>  Previous to Romantic poetry, eighteenth-century moral philosophy had drawn extensively on the capacity of sympathy, as in Adam Smith’s The Theory of Moral Sentiments, where the concept functions as a vital element of fellow-feeling organizing the social world. However, the usage of the term “sympathy” as medical terminology gradually evolved in the nineteenth century to define, for example, the body’s nerve connections and vibrating fibers, lacking the sense of sympathetic communication. Nevertheless, without submitting or giving precedence to contemporary disciplines of knowledge, Romanticism’s fruitful association with the language rooted within a holistic conception of knowledge in eighteenth-century natural philosophy and the Republic of Letters manifests an eloquent “defence” of poetry. </p>