The Incisive Moment
Henri Cartier-Bresson at work.
(Note: In 1947, Cartier-Bresson helped found Magnum Photos. Since 2005, Slate and Magnum have jointly produced " Today's Pictures," which appears on Slate.)
Meghan O'Rourke is Slate's culture critic and an advisory editor. She was previously an editor at The New Yorker. The Long Goodbye, a memoir about her mother's death, is now out in paperback.