natural law 
noun
1 [mass noun] A body of unchanging moral principles regarded as a basis for all human conduct: an adjudication based on natural law...
- Moral philosophy reposes on natural law precepts as common presuppositions, but its advice will be true only in the main.
- Just War teaching is a derivation of basic moral principles from natural law.
- If history is divided into divine history, natural history, and human history, then law can be divided into natural law, human law, the laws of nations, public law, and civil law.
2An observable law relating to natural phenomena: the natural laws of perspective...
- They showed that the basic building blocks of life, amino acids, can be obtained from purely chemical elements by natural laws without intelligent intervention.
- Many scientists believe homeopathy violates natural laws, and thus any effect must be a placebo effect - the power of a patient's beliefs to influence treatment results.
- I still have a strong interest in any phenomena that would violate our known natural laws of physics and redefine our understanding of our universe.
2.1 [mass noun] Observable laws collectively.