Principles are made of God - the creator who is perfect. Laws are made of a person who is imperfect. Laws of nature are laws of Dharma. Laws made by a person are the laws of religion. They may be contradictory to the laws of nature.
Laws are elastic and suitable to all, always.
Laws are rigid and not necessarily always suitable. There is a scope of improvements according to the place, person and time. There is no scope of improvements according to the place, person and time. Laws of nature and suitability are final. The word of religious leader is final.