The day my border collie, Quiz, decides that from now on he only wants to have sex with other border collies will be the day on which I will start believing that racial identity and "blood ties" mean, objectively, more than absolutely f**k all.
In other words, a human idea only has substance if it would also have substance to a creature who is incapable of knowing it has or has not substance. Otherwise it is an idea born from accidentals and its power and its illusion of reality are born from the human imagination rather than from the stuff of real life.
Back in the bad old days, Ray Charles walked into a whites only bar.
What the fuck are you doing in here?" asked the barman. "Can't you read the sign on the door?"