the law:abstract and universal

one can learn in history and law that the law is abstract and universal, this means for al , for the law comes from the people to the people, the citizen and this rules across the world. this principle comes from the greco-roman law that was recuvered in late midle ages-renaissance and gained force with xviii century revolutions(british, american and french). for this there ain´t an diference between private and public for the law is for al