Seventeen years after the Declaration, as secretary of state, Thomas Jefferson wrote Opinion on the French Treaties. In it, he espoused natural law based in human nature: “Questions of natural right are triable by their conformity with the moral sense & reason of man. Those who write treatises of natural law, can only declare what their own moral sense & reason dictate in the several cases they state.”30 The Declaration, a pinnacle of natural law, is built on humans’ moral sense and reason.
