I read about natural law for many years, but it really had little in common with my law practice. I defended people accused of crimes in the U.S., so of course I had to focus on the U.S. constitution and the bill of rights. The U.S. was founded on the English common law system. There is a slight overlap there with Natural Law as I believe you mean it, but not much. Of course my purpose as a lawyer had to be to work within the system, while always hoping the system would change.