Supreme Court Justice Thurgood Marshall told this story: There were two unmarried sisters who had such a bitter fight that they stopped speaking to each other. Unable or unwilling to leave their small home, they continued to use the same rooms and sleep in the same bedroom. A chalk line divided the sleeping area into two halves. The chalk divided rooms so that both sisters could come and go and get her own meals without trespassing on their sister's space. In the black…