Gaston Bachelard

Bachelard argued that scientific knowledge does not advance through steady accumulation but through breaks or ruptures that overturn everyday intuition and prior conceptual frameworks. Scientific progress requires overcoming what he called "epistemological obstacles"—habits of thought rooted in common sense that block genuine understanding.

Bachelard wrote a celebrated series of works on the poetics of imagination organized around the classical elements: The Psychoanalysis of Fire (1938), Water and Dreams (1942), Air and Dreams (1943), and Earth and Reveries of Will (1948). Each explores how elemental imagery shapes human reverie, creativity, and emotional life.

Foucault adapted Bachelard's concept of epistemological rupture into his own notion of epistemes—historical frameworks that define what counts as knowledge in a given era. Bachelard's collaborator Georges Canguilhem served as a direct intellectual link between Bachelard and Foucault.

Bachelard was both, and he deliberately kept these two domains separate. He held the chair of history and philosophy of science at the Sorbonne while also writing extensively on imagination, poetics, and reverie, publishing influential works in each field throughout his career from the 1930s to the 1950s.