Ideals are very often formed in the effort to escape from the hard task of dealing with facts, which is the function of science and art. There is no process by which to reach an ideal. There are no tests by which to verify it. It is therefore impossible to frame a proposition about an ideal which can be proved or disproved. It follows that the use of ideals is to be strictly limited to proper cases, and that the attempt to use ideals in social discussion does not deserve serious consideration.
William Graham Sumner (2007). “Folkways: A Study of Mores, Manners, Customs and Morals”, p.201, Cosimo, Inc.