In striving for the preservation of mind and culture on earth, it is vital that we obtain a clearer understanding of the limits placed upon us by nature. Yet we must recognize the significance of cultural takeoff and the great difference between biological and cultural evolution. We must rid ourselves of the notion that we are an innately aggressive species for whom war is inevitable. As the evidence shows, we must reject, as unscientific, claims that there are superior and inferior races and that the hierarchical divisions within and between societies are the consequences of natural selection rather than of a long process of cultural evolution. (Marvin Harris)