Antonyms of constitution:
higher law.
Examples of usage:
  1. My only advantages were a good constitution and the fact that I came of gentle people.
    "Peter A Novel of Which He is Not the Hero", F. Hopkinson Smith.
  2. It is like a king giving his subjects a constitution.
    "Expositions of Holy Scripture Genesis, Exodus, Leviticus and Numbers", Alexander Maclaren.
  3. Unless you are blessed with a cast- iron constitution and a stomach of the same pattern, you are not likely to survive.
    "The Boer in Peace and War", Arthur M. Mann.