The Discovery Institute (DI) is a religious think tank that drives the intelligent design movement. The Institute's Center for Science and Culture (CSC) counts most of the leading intelligent design advocates among its membership, most notably its former program advisor the now deceased Phillip E. Johnson. Johnson was the architect of the movement's key strategies, the wedge strategy and the "Teach the Controversy" campaign. The Discovery Institute and leading proponents represent intelligent design as a revolutionary scientific theory. The overwhelming majority of the scientific community, as represented by the American Association for the Advancement of Science, the National Academy of Sciences and nearly all scientific professional organizations, firmly reject these claims, and insist that intelligent design is not valid science, its proponents having failed to conduct an actual scientific research program. This has led the movement's critics to state that intelligent design is merely a public relations campaign and a political campaign.