Stephen Jay Gould (1941-2002) was a famous 20th century scientist based in New York City, as well as one of his generation's most highly read popular science writers. Gould specialized in paleontology and evolutionary science. He taught at both Harvard and NYU while working most of his life at the American Museum of Natural History. In 2000, the Library of Congress named him as one of its "Living Legends." He battled various cancers throughout the final 20 years of his life and finally succumbed to a form of lung cancer in 2000.

"Facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts do not go away while scientists debate rival theories for explaining them."

-from "Evolution as Fact and Theory", pp. 254–55, originally appeared in Discover Magazine, May 1981.