The intellectual formulas borrowed from natural science, which have cramped and distorted the operations of history as thought, have taken two forms: physical and biological. Charles Beard's presidential address to the American Historical Association in 1933, in which he outlined his view of the function of a historian and of the nature of written histories, affords an opportunity to see how one famous scholar expressed a blend of philosophic pragmatism and progressive faith. Improvement of society could therefore be effected by bettering the environment of potentially good mankind. This concept was the generating force behind reform enterprises, both before and after World War I, as campaigns for tenement house legislation, child labor laws, improvement of working conditions, and various social security plans. Beard’s conclusion was that the historian had to adopt a philosophy of history, or a criterion for selection of data, before he could write a history.