Natural Law
from 1270
There are standards of right and wrong built into what human beings are, discoverable by reason, and a law that violates them is not properly a law at all.
- Active
- from 1270
- Where
- Paris, Salamanca, and every subsequent court
- Status
- living
- Tradition
- Christian
The claim
Good is to be done and evil avoided — and beyond that first precept, the goods a rational animal is directed toward can be worked out: life, procreation, society, knowledge and reasonable conduct.
What it held
Natural law starts from a claim about human nature rather than about divine command, which is what distinguishes it from the voluntarist alternative and what allows it to be argued with people who do not share the theology.
Aquinas sets out four kinds of law. Eternal law is God's ordering of everything. Natural law is the rational creature's share in that, known by reason without revelation. Divine law is what revelation adds. Human law is what legislators make, and it derives its force from conformity with natural law — which yields the tradition's most consequential sentence, that an unjust law is not law but violence.
The Spanish scholastics at Salamanca then did something remarkable with it. Confronted with the conquest of the Americas, Vitoria argued from natural law that the indigenous peoples had genuine dominion over their lands, that discovery conferred no title, and that unbelief was no ground for conquest. Las Casas took it further. This is the point at which natural law becomes a theory of rights that can be turned against the power that funds the university.
How it argued
Practical reason working from what human flourishing requires, tested against cases — which is why the tradition is so much at home in law.
What it was arguing against
Divine command theory, on which the good is whatever God ordains; and later legal positivism, on which law is whatever is enacted.
Where it disagreed with itself
Whether natural law is inferred from human nature or grasped as self-evident by practical reason, which divides the traditional reading from Finnis' new natural law. Whether it can survive without theism — most modern proponents argue that it can.
Common misconceptions
That it means whatever is natural is good. Aquinas' natural is what reason discerns as fulfilling human nature, not what happens frequently. And it is not a Catholic doctrine only: Grotius and Locke are natural lawyers, and the American founding documents are written in its vocabulary.
How it began
Stoic and Roman legal ideas of ius naturale, given a systematic theological setting by Aquinas in the Summa's treatise on law.
What became of it
Displaced by positivism in the nineteenth century, revived after 1945 — the Nuremberg tribunals needed a standard above enacted law, and this was the available one.
Lasting influence
International law through Vitoria and Grotius. Human rights language. The American Declaration of Independence. Martin Luther King cites Aquinas on unjust laws from Birmingham jail.
Why it still matters
It is one of the two or three live positions in legal philosophy, and the standing alternative to the view that law and morality are separate questions.
Put another way
A plumb line held against a wall that was built to look straight.
Where to start
The treatise on law itself. It is unusually clear and it is only a few questions.
The surprising bit
Vitoria's lectures arguing that Spain had no right to the Americas were delivered at a university funded by the crown that was conquering them, and Charles V ordered him to stop.
In their own words
An unjust law is no law at all.
Good is to be done and pursued, and evil avoided.
Connections
- Answers
- Thomism
- Influenced
- Latin American Scholasticism
The verdict
A medieval theory of law that keeps being needed whenever positive law runs out.