At the end of the eighteenth century, scientists for the first time demonstrated what medieval and renaissance alchemists had long suspected; ice is not lifeless but vital, a crystalline revelation of vigorous powers. Studied in esoteric and exoterical representations of frozen phenomena, several Romantic figures - including Coleridge and Poe, Percy and Mary Shelley, Emerson and Thoreau - challenged traditional notions of ice as waste and instead celebrated crystals, glaciers, and the poles as special disclosures of a holistic principle of being. The Spiritual History of Ice explores this ecology of frozen shapes in fascinating detail, revealing not only a neglected current of the Romantic age but also a secret history and psychology of ice.