In the twenty-six texts on aesthetics collected in this posthumously published volume, Gaston Bachelard (1884–1962)—a French philosopher who “grants himself the right to dream” and to “immerse himself in a meditative reverie on the nature of things”—explores the realm of active imagination. He finds this realm not only in the visual arts (Monet, Chagall, Flocon, and others) and in poetry and prose (Rimbaud, Poe, Balzac, and others), but also in dreams, radio, stillness, and solitude. His reveries resonate with the call of the elements and the “logosphere”; the magic of the mask and an “iron cosmos” come to life, and the psychological depths of a “primer on solitude” are revealed. By interweaving a subtle analysis of the dreaming mind with existential, dynamic, and ethereal reveries—reveries of ink, force, and stone, as well as those of silence and music—Bachelard asserts that this capacity for dreaming is an inherent human right, essential for achieving wholeness and a profound communion with nature.