Natural Law Theory
Aquinas Foremost theologian of the Catholic Church. His main work was Summa Theologica.
For contemporary readers the book is one weird structure.
The Form of Aquinas’s Arguments
2. A statement of authority
3. A statement of his own claim
4. A rhetorical question
5. Rejection of all objections
Of the 15 articles, the most important topics are what is law and what is the nature of law, not the
Aquinas gives the following definition of what law is
1. An “ordinance” of reason
2. Its end is that of the common good
3. It made by someone who has “the care of the community”
4. It is promulgated
Law and Reason
a) Law can be in things in two ways 1) in essence and 2) by participation
b) An act is different from its result,; the former is speculative while the latter is practical
c) An action emanates from volition (will), but for the will to have the nature of law it needs
to be the mark of reason.
Aquinas makes the distinction between “practical reason” and “speculative reason”. Practical
reason is normative, it tells us how we ought to act, while speculative is proposition knowledge
of the way things are. So law has reason because law directs our actions, and actions are
guided by practical reason. However, reason tells us to take steps to achieve our desired result.
Law being an rule of practical reason requires it to have an end that needs to be achieved.
Aquinas says that this end is the common good.
Law and the Common Good
1. Common good is applicable to particular ends
2. Particular interests and concerns are referable to the common good
According to Aquinas, happiness is the final goal of human action and also the first dictate of
practical reason. Thus if everyone were acting with “reason” the result would be happiness. This is not just the happiness of a few people or the rulers, but a common happiness. Aquinas
wishes to dismiss old Roman philosophy that law is what the ruler pleases, which he does by
insisting that the law requires the force of reasons and must be aimed at the common good.
Also be aware that common good, does not mean an aggregate sum of individual happiness or
even reflected shared interests of the majority or all of society. By “common good” Aquinas
means the “interests that all have as members of the perfect community or politic.”
Aquinas draws on Aristotle and other Christian theologians by stating that human beings only
ahcieve true happiness in a political society. He gives the following reasons for this
1. Human beings do not have the same natural advantages animals have with regard to
satisfying their physical needs
2. In order for humans to survive they require multiple individuals, with people performing
different tasks based the division of labour and on what people are good at.
3. This diversity needs to be unified and order needs to be esbalished through law
4. Thus human’s not only need political society to satisfy their physcial needs but also their
intellectual needs as human beings.
Who makes Law?
- Law making belongs to the public or its representatives because
o Coercive power belongs to the public, and
o Because particular goods are tied to the good of the state, and
o Because the common good belongs to the whole people
A lawful community of the state can make law
Since laws govern the whole people, it should thus, be the people (or its representatives) that
make the law. Note that representatives does not mean democratic representation. (He
preferred a monarchy)
Aquinas believes that some people are born to rule and others to be rules, and that this is
natural. Virtue is what determines how fit someone is to rule so that they can achieve the end
of providing order to that the common good may be achieved.
The lawmakers or enforces must have the power of coercion in order to function. The political
rulers must be able to punish those who transgress the law.
Law and Promulgation
Two justifications for promulgation
Aquinas makes the logical point that in order for a law to be a law, it needs to be broadcast to
all in society. Any law that the ruler might think of, but never voices would obviously not be a
law. There are two reasons for this Pragmatic In order for people to follow the law they need to know what it is
Normative That people are morally obliged to follow just laws and ought to be punished for
disobeying them. However it would be morally wrong to punish someone for breakng a law
they could not have known about.
What is Natural Law?
Four different kinds of law: Eternal Law, Natural Law, Human Law, Divine Law
The way to understand the four kinds of laws are to answer the following five questions about it.
1) Who makes it?
2) Whom does it govern?
3) What is its cause?
4) How is it promulgated
5) Is it a command of reason?
1) Since law is imposed on someone who is not there for eternity
2) Since promulgation cannot be for eternity
3) Since particular ends that are attained by law cannot be eternal
It follows that law is not eternal