True, but the same can be said for many, many ideas, philosophies, and world religions.
Can you prove Christianity is true? Can you prove Christ died for our sins? Can you prove that the Holy Ghost is real, and can teach us the truth of all things?
Not to anyone but myself. Christianity is based on faith. That's the way God designed it. And we have the scriptures to support these views. (We'll leave it at that.)
But there is no inspired Word of God for the natural law hypothesis. It's like believing the ten tribes of Israel settled in the US. People develop all sorts of philosophies and use scriptures to support their position. Or evolution and gathering spurious data to support the contention while ignoring other evidence to the contrary.
A person can choose to believe natural law or not. Lots of far great men of faith then I'll ever be believed in it. To me it doesn't make any difference unless someone chooses to shade their theology according to this philosophy which is not based on scripture. That is always a danger in these types of things. I personally don't accept anything unless I'm certain it's true.