He was referring to heredity and genetics. Example, if you're the kings new born son, you are automatically known as the next king after the present one. If you were black, you were automatically known as a slave.
i think he is referring to the destiny of a person since in their time they based things on the stars also it can refer in the kind of the family that the child belong when they are born. But in our time it can based on the kind of family that we have
