Book excerpt: Goethe's ideas on colour and imagery crossed many borderlines: those of artistic processes and philosophical aesthetics, art history and colour theory, together with the science of perception. This investigation into his writings ranges across art from Antiquity, the Renaissance and the eighteenth century, as well as exploring the centrality of these issues to Goethe's literary work. Questions find answers, but also raise new questions. This systematic sequence of essays, originally written between 1999 and 2011, appeals to readers in all these separate areas, while drawing together their essential coherence.