Decisive moment, a concept central to 20th-century photography, formulated by Henri Cartier-Bresson in his eponymous, landmark book of 1952. (Images à la sauvette, the French original, appeared the same year.) Out of the chaotic, unceasing flux of the visible world, the decisive moment appears as an instant of equilibrium perceived by the photographer through the camera's viewfinder. In such an instant, compositional resolution is seen to represent the psychic dimension of underlying social and political realities. In The Decisive Moment, Cartier-Bresson writes: ‘To me, photography is the simultaneous recognition, in a fraction of a second, of the significance of an event as well as of a precise organization of forms which give that even its proper expression.’ What he was advocating was essentially stylish reportage—photography alive with social portent, seized on the fly, shrewdly observant of beaux-arts principles of composition. In his adherence to both social significance and formal resolution, as well as his reverence for the unmanipulated negative, Cartier-Bresson defined a photographic position squarely situated within modernist artistic practices.
A precursor of Cartier-Bresson was E. Giard, whose book Letters sur la photographie (1896) proffered, like numerous others of the period, counsel on the practice of instantaneous photography. Giard's advice—to anticipate the point mort (dead point), or pause in the movement of an animal or mechanism—was a key strategy for early photo-reporters who came to define their profession during the late 1890s.
— Kevin Moore
