That which you do not bring to consciousness comes to you as your Fate, that which you do bring to consciousness, whether it was what you thought you wanted or not, is your destiny.
Since biological change occurs slowly and cultural changes occur in every generation, it is futile to try to explain the fleeting phenomena of culture by a racial constant. We can often explain them-in terms of contact with other peoples, of individual genius, of geography-but not by racial differences.