It is a peculiar sensation, this double-consciousness, this sense of always looking at one’s self through the eyes of others, of measuring one’s soul by the tape of a world that looks on in amused contempt and pity. One ever feels his two-ness, – an American, a Negro; two souls, two thoughts, two unreconciled strivings; two warring ideals in one dark body, whose dogged strength alone keeps it from being torn asunder
This sentence is from Du Bois' book, The Soul Of Black Folk.
This seems to mean that black Americans have both an American self and a black self, but the previous part is too difficult to interpret. Can you help me interpret it?