A quote from Du bois work, from a reader.

It is the thought of a negro of Northern education who has lived long among his brethren of the South yet who can not fully feel the meaning of some things which these brethren know by instinct — and which the Southern-bred white knows by a similar instinct: certain things which are by both accepted as facts — not theories — fundamental attitudes of race to race which are the product of conditions extending over centuries, as are the somewhat parallel attitudes of the gentry to the peasantry in other countries.