Intellectual Origins of Natural Rights
There was a natural law tradition from antiquity and the middle ages. Natural law is the oldest and most frequently used concept of political theory. Natural law is the principles that are to be established if justice were to prevail. Or, it is the scientific laws of man and his environment.
From the 5th century until the end of the 18th century the doctrine of natural law as a moral philosophy played a major role. Legislative law which rules today is the opposite of natural law.
In some ways Aristotle was an ancestor to the natural rights tradition, seen clearly in his view of property rights. He preferred private property, common use. Most of us prefer private property, private use. Christianity was born with the concept of natural law. It is at the center of our idea of individuality. This idea is linked to modern natural rights theory. Thomas Aquinas‘s pinnacle is the natural law doctrine. For him there was no conflict between faith and reason. Natural law is not God’s will. It is God’s plan. We call it freedom. Aquinas never imagined a coercive state.
From the 2001 History of Liberty seminar.