Full Idea
Natural law is certain propositions of immutable truth, which guide voluntary actions about the choice of good and avoidance of evil, and which impose an obligation to act, even without regard to civil laws, and ignoring compacts of governments.
Clarification
'Immutable' means can't be changed
Gist of Idea
Natural law is immutable truth giving moral truths and duties independent of society
Source
Richard Cumberland (De Legibus Naturae [1672], Ch.I.I)
Book Reference
'British Moralists 1650-1800 Vol. 1', ed/tr. Raphael,D.D. [Hackett 1991], p.79
A Reaction
Not a popular view, but I am sympathetic. If you are in a foreign country and find a person lying in pain, there is a terrible moral deficiency in anyone who just ignores such a thing. No legislation can take away a person's right of self-defence.