What was to be done so that these peoples, so different, might live in good intelligence? … Napolean [thought that] men [sh]ould each marry two women of different color. Then the children of this double marriage would be raised together and, in spite of the difference in color, they would become accustomed to living together and would consider themselves equal.
Actually that's what happened in practice wherever slavery was an institution, masters begetting children from more than one woman and of more than one color. However, because the mothers were not considered equal the children were not considered equal. The kids may have played together, but they were raised on two tracks. Kind of like boys and girls, you know? O Napolean, keep thinking!
The quote is from Jean Descola's Les Messagers de l'Independence as it appears in an endnote of German Arciniegas's America in Europe: a history of the New World in reverse.