David Lee Hull was a philosopher with a particular interest in the philosophy of biology. In addition to his academic prominence, he was well known as a gay man who fought for the rights of other gay and lesbian philosophers.
Hull was one of the first graduates of the History and Philosophy of Science department at Indiana University. After earning his PhD from IU he taught at the University of Wisconsin–Milwaukee for 20 years before moving to Northwestern, where he taught for another 20 years. Hull was a former president of the Philosophy of Science Association and the Society for Systematic Biology. He was particularly well known for his argument that species are not sets or collections but rather spatially and temporally extended individuals.
Hull also proposed an elaborate discussion of science as an evolutionary process in his 1988 book, which also offered a historical account of the "taxonomy wars" of the 1960s and 1970s between three competing schools of taxonomy: phenetics, evolutionary systematics, and cladistics. In Hull's view, science evolves like organisms and populations do, with a demic population structure, subject to selection for ideas based on "conceptual inclusive credit." Either novelty or citation of work gives credit, and the professional careers of scientists share in credit by using successful research. This is a "hidden hand" account of scientific progress.