Natural Law in a ‘nutshell’
Key Figure: Thomas Aquinas Key Terms: Thomism; reason; purpose; deontological;
prescriptive, legalistic.
St Thomas Aquinas a Christian philosopher of the 13th Century
argued that natural law was reflected in nature in a moral way,
insofar as it fulfilled the purpose for which it was created by God.
Key Propositions:

Humans have an essential rational nature established by
God, who designed humans for a purpose - to live and
flourish in prescribed ways which are discoverable by the use of reason.

These ways of living apply to and are discoverable by all humans, regardless of
whether they believe in God or not, by use of their reason.

These ways of living are called Natural Laws. They are universal and
unchangeable. Societies and their laws can be judged by their conformity to
Natural Laws. Any laws not in line with natural law are not true laws, but
counterfeit. The basis of natural law moral theory is the claim that standards of
morality are in some sense derived from, or entailed by, the nature of the world
and the nature of human beings.
Key Precepts of Natural Law

Good should be promoted and carried out

Evil must be identified and avoided.
Primary Precepts; namely the key purposes of human existence

Preservation of life

Ordering society for the benefit of its members

Worshipping God

Education

Reproduction of the species
We must bear in mind that what made Aquinas' outlook different from the Greek
philosophers by which he was influenced in his thinking, is that he believed in a personal,
creator God, and believed that the human soul survived death. Therefore, for Aquinas, the
final purpose of human life has an eternal, and not merely a temporal dimension. God
Himself is the final purpose of humans.
Aquinas argued that because humans are created by God, they basically want 'good'
things. Paul may have been expressing something like this in Romans Chapter 7 when he
said that he wanted to do the right thing, but found himself doing the wrong thing
instead. In Chapter 1 and 2 he expresses even more clearly what Aquinas meant when he
insists that the knowledge of what God is, and what God requires is known to all people.
Paul however, appears to recognise that humans can consciously wish to reject the ways
in which God wishes them to live. Aquinas appears to reject this. Hitler and Stalin, he
may argue, did not SEEK to do evil, but they were mistaken in what they termed as 'good'
- they were pursuing what Aquinas terms 'apparent good'.
Aquinas is prepared to concede that some humans desire what he terms 'apparent good' that is, something which will gratify an immediate desire, but will ultimately lead
humans away from the ultimate purpose of existence - a relationship with God. Examples
of apparent good could include getting drunk, taking addictive drugs, overeating, taking
revenge on someone who has hurt you, etc. The pursuit of 'apparent good' is sin.
In pursuing any activity in such a way that it impedes any of the five keys purposes of
human existence; Aquinas calls these purposes the Primary precepts. Acts which uphold
and further these precepts are deemed good. Acts which do not are called bad. Secondary
precepts are RULES which direct people TOWARDS actions which uphold primary
precepts and AWAY from actions which undermine primary precepts. For instance,
sexual intercourse which is intended by the couple to be fruitful is a good act, for it is
aimed at reproduction of the species. Aquinas would wish, of course to add that the
couple should be married - marriage being one of the bedrock units for the raising of
children within a well-ordered society. However, sexual intercourse, or any other form of
sexual activity which is designed solely for gratification without the possibility of
procreation is bad.
Hence the way in which the Roman Catholic Church, influenced by Thomist Natural
Moral Law, has understood the use of contraception. The act of Sexual Intercourse (it is
argued) is clearly designed by God for the purpose of creating new lie, i.e., reproduction of
the species. From this 'primary precept', the Magisterium of the Roman Catholic Church
(it's governing body) has deduced that any act of sexual intercourse using devices which
are designed to thwart that natural purpose (i.e. artificial contraception) is therefore
intrinsically wrong because it deliberately prevents the creation of new life. In the same
way, masturbation and homosexual sex are intrinsically wrong because these sexual acts
are, by their very nature, incapable of producing new life.
We could sum up Aquinas' view of the moral life as 'that lived according to reason'. But
how can we know that we are using reason correctly? After all, we have just seen that it is
possible to use reason to pursue what appears to be good but is, in fact, evil. One way we
can check on our reason is, Aquinas suggests, by considering what he calls the interior act.
One can identify interior acts with motives. Aquinas recognises (with Jesus, Paul and
others) that it is possible to perform a deed (an exterior act) with the wrong motives.
Jesus' example of the man who prays on the street corners to be admired for his piety, or
who gives to the poor in a blaze of publicity so that everyone will admire his generosity, is
excellent.
Aquinas insists that both the interior and exterior act to be important. The exterior act
may be intrinsically good, but for humans, who are eternal creatures, the motive and end
purpose of the act is just as important, because the ultimate end for humans is God and his
glory. Any action which upholds the Primary Precepts is good, because it furthers the end
of humanity, which is to glorify God.
As to character, Aquinas believed that there were characteristics which humans should
develop, because they would bring the believer closer to God. There are seven of them
and they are faith, hope, charity (agape, or Christian love), fortitude, justice, temperance,
prudence.
Aquinas distinguished between four types of law: eternal, natural, human and divine

Eternal~ The whole world is governed by God’s mind, and is therefore subject to
the governance of eternal law

Natural law~ As we are humans and intelligent creatures, we are able to make this
eternal law our own and so natural law is the sharing of eternal law by intelligent
creatures

Human law~ Limited by our own inadequacies, these laws necessary and are
derived from the natural laws and,

Divine law~ Essential for salvation as Aquinas believes humans have been
apportioned an eternal happiness in excess of their natural resources. This is
directed by a divinely given law and revelation.
A key assumption Aquinas makes is called the SYNDERESIS RULE that we naturally
"do good and avoid evil" which is the opposite of the REFORMATION assumption that
"all have sinned and fall short of God's glory" (Romans 3:23). We are born with good
natures, able to reason and so pursue good ends or objects of the will. The DIVINE LAW
reflects God's eternal law and is revealed in holy SCRIPTURE (e.g. Ten Commandments
[Exodus 20]). From these observable rational ends we get the PRIMARY PRECEPTS
‘…each precious child, born
with the desire to do good
and avoid evil…’
1. Natural Law -"right reason in agreement with nature". Cicero
2. AQUINAS sought to reconcile Christian thought with Greek thinking.
Aristotle developed Natural Law and Aquinas (C13) built on his thought
3. The ability to reason was vital for Aquinas; reason can determine what acts are
necessary for the good of a human being whether this is taking food/drink or
acting morally.
4. Aquinas considered that Natural Law was the moral code which human beings
are naturally inclined towards. God reveals specific commands, but these do
not go against natural law but rather further and develop it.
5. The purpose of human existence did not lie entirely in this life. The first
priority laid down by natural law was that the self had to be preserved not just
in this life but beyond the grave. If the self gave in to non-rational desires, then
it became enslaved.
6. It was possible to arrive at the natural or cardinal virtues (prudence,
7.
8.
9.
10.
11.
12.
13.
temperance, fortitude and justice) by the use of reason alone. The Ten
Commandments (with the exception of the command to keep the Sabbath day
holy) were held to be examples of natural virtues. These natural virtues are
expanded by the revealed virtues (of faith, hope and charity - derived from St
Paul: 1 Corin 13:13)
For Aquinas, the purpose of human life Reason is used to find out God's
intention and the purpose of human existence and this will enable one to arrive
at the principles of natural law.
a. Preservation of life
b. Ordering society for the benefit of its members
c. Worshipping God
d. Education
e. Reproduction of the species (i.e. the primary Precepts). 'Natural law is
the same for all men ... there is a single standard of truth and right for
everyone…which is known by everyone' (II.i Q. 94 art. 4).
Secondary Precepts ‘back-up’ primary precepts, e.g. Do not abort the unborn,
do not murder. Secondary precepts - applications of the primary precepts using
human reason, which are not absolute.
Natural Law can show all human beings what is good — religion is not needed
for this and this is similar to St Paul's claim that the law is written in the hearts
of all men (Romans 2:14).
Aquinas considered, following Aristotle, that all men will the good. He also
considered there to be real and apparent goods.
1. Real goods are acts done from human reason which correspond to the
natural law
2. Human beings may seek some apparent good, but this is not true good —
it is only an apparent good because it does not conform to the perfection of
the human nature which all human beings share (e.g. adultery) : 'A
fornicator seeks a pleasure which involves him in moral guilt' (Summa
Theologica). The fornicator (sexually immoral) seeks a pleasure which he
thinks is a good, but this is only an apparent good as it diminishes a human
being's nature. Apparent goods - acts done from reason which do not
correspond to the natural law.
Aquinas also distinguished 'interior acts' and 'exterior acts' and is clear that the
former are the most important — indeed morally good or bad acts are generally
interior acts.
An act may be good in itself but done for a wrong intention (e.g. Parable of
the Pharisee and the Tax Collector- Pharisee stood up and prayed about
himself…I fast twice a week and give a tenth of all I get’. Tax Collector
hides in the shadows, beats on his chest and says, “God have mercy on me,
a sinner.”)
For Aquinas, there is only one final end, and that is God.
Aquinas considers that all human beings share a single nature and, therefore,
there should be a single aim or objective for all human beings - this justifies
him in rejecting knowledge as an aim (see also criticism about NL being elitist) as
only some people have the ability to seek this knowledge. The one thing that
every person can desire is the vision of God which is promised for the next life.
14. Synderesis - the assumption that we by nature seek to do good and avoid evil -
or have an innate knowledge of first principles (the primary precepts).
15. Primary precepts - principles known innately which define the rational ends or
goods of human existence.
16. A moral life is a life which is lived according to reason. An immoral life is one
which is at odds with reason
17. Eudaimonia: Humans have a natural tendency towards human flourishing
(happiness or well-being (eudaimonia)). For Christians, a blissfully happy
vision of God. This is the "end" of humans...and is the main spur for
morality in all people.
18. Morality is to be discerned through the use of "practical reason".
19. Cardinal virtues: Moral virtues acquired through practice
1. TEMPERENCE governs the passion of desire,
FORTITUDE those of anger and fear:
3. JUSTICE governs the dealings of men with one another in accordance with
the principle of fair distribution:
4. PRUDENCE determines what is right in every case.
2.
The cardinal virtues control the principal areas of moral conduct and provide the general
conditions necessary for all moral virtues.
1. Moral virtues, (good habits); acquired by constant practice and exercise and it is
possible for the natural man to acquire them. No one is born with a virtue, because a
virtue is a habit; we are able to reason and as such, have the capacity to develop such
virtues.
2.
Theological virtues infused by God and his abounding grace.
o Faith
o Hope
o Charity
Strengths of Natural Law

The certainty offered by application of Natural Law theory can give security to a
society.

The principles of Natural Law can apply to a society and function even if God was
taken out of the system.

Aquinas suggests that all of humanity shares a common purpose and origin, which
overrides any other cultural or racial difference.

There are real reasons to live a moral life, lasting benefits to be enjoyed by fulfilling
the purpose for which humans are upon the earth

Natural Law is a complete way of life, dealing with character, motive and action. It
gives a day-to-day and lifelong system for living a moral life. It removes cultural
boundaries and demands equality between individuals.

Natural Law theory has no problem in calling certain acts intrinsically wrong, such as
torture, fraud, sexual exploitation etc.
Weaknesses of Natural Law

The Natural Law theory rests on the assumption that humans everywhere share a
moral sense of what is right and wrong. Anthropological studies of different cultures
challenge this assumption that there is not this moral consensus throughout the
world, even on such apparently basic principles such as 'Murder is wrong'.

Natural Law also suggests that humans share basically the same nature, and that
any deviation from that nature is unnatural. Try telling that to someone of the gay
community or someone who is celibate

Natural Law as it is applied by the Roman Catholic Church has been criticised for
being rigid, inflexible and legalistic. The use of the principle of Double Effect to
determine whether a woman whose life is threatened by the continuance of a
pregnancy may take action to save her life which will endanger or kill her unborn child
is an example of what critics might be referring to here.

If the world as we know it was not created, but the result of a cosmic accident, then
there is no design or purpose to human life and the concept of an 'inbuilt' nature
placed there by a Creator to whom we are responsible is meaningless.