Arthur Fisher Bentley (October 16, 1870 in Freeport, Illinois – May 21, 1957 in Paoli, Indiana) was an American political scientist and philosopher who worked in the fields of epistemology, logic and linguistics and who contributed to the development of a behavioral methodology of political science.
He received his Bachelor of Arts in 1892 and his Ph.D. in 1895 from Johns Hopkins University. He was the second person to win the American Humanist Association's Humanist of the Year Award, in 1954. He moved to Paoli, Indiana in 1910 where he lived for the rest of his life.
Bentley held that interactions of groups are the basis of political life, and rejected statist abstractions. In his opinion, group activity determined legislation, administration and adjudication. These ideas of process-based behavioralism later became central to political science. His tenet that "social movements are brought about by group interaction" is a basic feature of contemporary pluralist and interest-group approaches.
His work The Process of Government, published in 1908, had much influence on political science from the 1930s to the 1950s. Although initially not of consequence, it influenced other groups such as the Chicago School who also tried to develop objective, value-free analyses of the political field. This influence is still felt decades on (1983 : Institut d'Etudes Politiques de Grenoble, Mémoire "Décision Groupale et Réalité Démocratique dans The Process of Government", P. Chabal).
His paper "The Human Skin: Philosophy's Last Line of Defense" (1941) was published in Philosophy of Science 8 (1941): 1-19. and is available from the Mead Project at Brock University 
In 1949, he co-authored Knowing and the Known, a series of papers on epistemology, with John Dewey.