Moyers also referred to what historian Clinton Rossiter called the period of "the great train robbery of American intellectual history," when "conservatives—or better, pro-corporate apologists" began using terms such as "progress", "opportunity", and "individualism" to make "...the plunder of America sound like divine right." He added that Charles Darwin's theory of evolution was also used by conservative politicians, judges, and publicists to justify the idea of a "natural order of things" as well as "the notion that progress resulted from the elimination of the weak and the 'survival of the fittest.'"