The lexeme Zusammenhang (nexus) was introduced into philosophy by the German rationalists, who conceived of the world as a multiplicity of independent substances coordinated in a system of pre-established harmony. In his critique of these metaphysicians, Kant insisted that things hang together in not one but two ways—as an aggregate of a posteriorisense data, or as a system of a priori concepts—and that these two nexus are separated by an epistemological chasm. This entry proposes that Goethe’s nexus concept recovers the middle term excluded by Kant’s binary distinction and that this middle term plays a key role in both his scientific and literary writings, including the Hefte zur Morphologie (1817-1824; Notebooks on Morphology), Wilhelm Meisters Lehrjahre (1795-96; Wilhelm Meister’s Apprenticeship), and Die Wahlverwandtschaften (1809; Elective Affinities). By comparing Goethe’s theoretical use of the nexus concept with his literary use of the nexus motif, this entry articulates a relation of part to whole that displays more coherence than a mere aggregate, yet is more dynamic than an absolute system.