The German Romantic poet and philosopher Novalis (Georg Philipp Friedrich von Hardenberg) left behind his unfinished novel 'Heinrich von Ofterdingen', published posthumously. The text opens with the young protagonist dreaming of a vast, mysterious cavern containing a glowing 'Blue Flower' (Blaue Blume) that bears a human face. This singular dream-image became the defining symbol of the entire German Romantic movement, representing the infinite, unquenchable longing for a higher psychological and spiritual reality hidden just behind the veil of everyday life.

Novalis explicitly equated dreaming with poetic composition, declaring that dreams are a protective shield against the monotony of life. His work established the Blue Flower motif, which altered the course of European lyric poetry by centering the pursuit of sub-rational, transcendent imagery as the absolute duty of the poet.