In Theodore W. Allen, "The Invention of the White Race" vol. 1 "Racial Oppression and Social Control," p. 9, Allen writes --
Historians are cautioned to avoid the vice of "presentism," that is, the assignment of motivations for behavior to suit current vogues without proof that those motivations actually figured in the needs and feelings of the people of the historic period under consideration. One common example of this error is that of casually classing Negroes in colonial Anglo-America as "slaves" from the first mention in 1619 on, decades before there is any justification in the record for such a generalization.