Differences are specific ruptures of a given spatio-temporal order. That is to say, specific criteria of order must be first laid out in order to construct differences. For example, the categories women, Jews, homosexuals, and persons of color are constructed out of a perception that men, Gentiles, heterosexuals, and white people represent prototypical patterns. It is the observation of a deviation from these patterns that produces the others. The homosexual is someone who has different sexual preferences from a heterosexual.
Black people are persons who differ from white people.
The search can only lead to the most influential texts in human civilization-Bible, Koran, Torah, Talmud, etc., etc. The intrinsic circularity of gender, racial, and ethnic identities is obvious. White people, Gentiles, men, and heterosexuals are defined with reference to the their differences from black people, Jews, women, and homosexuals, respectively. Whites people are persons who have no black blood, and one drop of black blood makes the difference from whiteness. Black blood marks a deviation from the order of whiteness.