This document discusses Thomas Aquinas's theory of natural law. It explains that Aquinas built upon Aristotle's idea that there is a natural order to the world and that things have a telos or purpose. For Aquinas, the four purposes of human life set by God are to live in society, reproduce, learn, and worship God. Any actions that fulfill these purposes are considered good. Immoral actions result from confusing apparent goods with the ideal good. The document provides examples of how Aquinas would view issues like abortion and homosexuality based on his theory that the purpose of sex is reproduction within marriage.

1. Natural Law.
Before looking at Natural Law in more detail consider these
statements and discuss them.
 Is it natural to be homosexual
 Is it natural to be violent
 Is it natural to be prejudice
 Is it natural to be monogamous
 Is it natural to commit suicide
 Is it natural to eat meat
 Is it natural to use contraception

2. The Natural Law approach to morality has a
long history.Cicero (106-43 BCE) stated ........
´True law is right
reason in agreement
with nature. It is applied
universally and is
unchanging and
everlasting´ The Republic

3. Aquinas and Natural Law theory

4. It was Aristotle who first developed this
approach to ethics but in seeking to
combine Aristotles thought with the
Catholic Churches teachings, Thomas
Aquinas built on his thought and
developed a system of ethics known as
Natural Law. The Catholic Church to
this day bases much of its teachings,
beliefs and practices on Aquinas’
natural law theory.

5. Aristotle (384-322 BCE)
 Telos (end/purpose) – The key idea
in Aristotle´s natural law is that there
is an unchanging order (principle) to
the changing physical world and by
understanding this we can learn what
is normal or natural for someone or
something to do, or be, or become.
(its telos). Aristotle distinguished
between efficient and final causes.
Efficient Cause (The means to an
end) - These are the things we do, to
achieve something. For example...


6.  Final causes (the end in itself) – The ´telos´ this is what
should happen if we do the right things. For example...
If we want a seed to grow, we plant it in
soil, fertilise it, water it and expose it to
sunlight
A seed will grow, provided we plant it in
soil, fertilise it, water it, and expose it to
sunlight. As far as Natural law is concerned,
we plant seeds, water them etc because this
is the way they grow and become plants.
This is because there is something within
the nature of the seed which responds to
these conditions. On the other hand, a seed
left un-watered will generally die.

7. For Aristotle the ´inner principle´of human
nature is REASON.
The human ability to reason is the ´driving force´of human
development and action. For instance, the ability to reflect on our own
behaviour and surroundings and change them in light of our thoughts
about them, is essentially what separates us from animals.
According to Aristotles philosophy something was ´good´ if it fulfilled
its ´telos´ (purpose) for which it was created for example....
A good knife is one that cuts well.
A good burger is one that is tasty and filling etc

8. Thomas Aquinas (1225-74)
The writings of Aristotle had been lost in the
West but had been preserved amongst the
Islamic scholars of the East. They were re-introduced
into Western thought shortly before Aquinas took up
a position as a professor at the University of Paris.
Aquinas believed natural law was the moral code which human
beings were naturally inclined towards. God reveals specific commands
but these do not go against natural law but rather further and develop it.
This reflected Aquinas´ approach to theology generally by which natural
theology (which was based on human reason) did not go against
revealed theology (which was based on revelation by God).
Aquinas said that ´the moral life is the life which is lived according to
reason.´

9. Based on Aristotles idea of the ´good´ being that
which fulfils the purpose for which it was created,
Aquinas believed it was necessary to establish the
purpose for which humans were created by God.

10. So consider this simple question.
What is the purpose of human life?
On the slip of paper provided
1. Write your answer
to this question
2. Fold it
3. Place in the box
To be done on your own
and with no discussing.

11. Some responses to this question.

12. Where am I? Who am I?
How did I come to be here?
What is this thing called the
world?
How did I come into the world?
Why was I not consulted?
And If I am compelled to take
part in it,
Where is the director?
I want to see him.
Soren Kierkegaard

16. Aquinas believed there were 4 ends (purposes) for which
human beings have been created.
1. To live harmoniously in society
2. To reproduce
3. To learn
4. To worship God
Based on Aristotle´s idea of efficient causes any action
which provides a means to these ends (efficient causes) is
considered ´good´. For example – providing food to
someone that is hungry, having sex with your wife in order
to have children, studying philosophy or science, praying to
God and going to church.

17. Apparent good versus Ideal good
God makes human beings with a certain ideal nature and this
nature enables human beings to use their reason and their
experience to understand what is right.
Immoral actions or ´sin´ according to Aquinas are not carried
out because of evil intent or a corrupted nature. Aquinas
believed humans to be fundamentally good as he believed we
are all created by God. The reason behind immoral action
is to confuse ´apparent good´ with the ´ideal good´.
Morally wrong actions are carried out by the individual in the
mistaken belief that they are ´good´when in fact they are ´not
good´.

18. God creates man with an ´ideal´ human nature that
we can all potentially achieve. Like the seed
reaching its potential of flowering. However, to ´sin
´ is to fall short of this ideal (the good), literally
meaning ´missing the mark´ (as in archery). People
often miss the mark because they confuse
apparent good with the ideal good (for example,
drinking alcohol may make me feel more sociable –
apparent good – but the ideal would be to feel self
confident and sociable without having to alter my
body chemically).
What would Aqunias believe about the following:
1. Abortion 2. Homosexuality 3. Genetic
Engineering.
No-one seeks evil for itself, it is only sought as an
apparent good and therefore rests on a mistake.
Hitler did not seek to do evil – he sought to do what
he thought was good but was mistaken. He strove
for the apparent good of ethnic cleansing rather than
the ideal (real) good of living harmoniously with
others.

19. ´Interior acts´ versus ´exterior acts´
Aquinas also distinguished between ´interior acts´ and
´exterior acts´ and is clear that the former are the most
important. An act may be good in itself but done for a
wrong intention – for instance giving to charity may be
good in itself but if it is done in order to attract praise and
attention, then it has been done from a bad intention.
Therefore our intentions as well as our actions are important
when seeking to live a virtuous and moral life and striving
to reach the potential for which God has created us for.

20. Putting Aquinas´ natural law into action and
looking at case studies.
Natural law recieves the most attention and criticism today when we
apply the thinking to the liberal sexual attitudes of today.
Based on Aquinas´understanding acts such as homosexuality, use of
contraception and masturbation are all immoral actions. The ideal
purpose of sex is for reproduction within the confines of marriage. Any
sexual act contrary to this is considered ´unnatural´ and therefore
immoral. The Catholic Church has established its doctrines on the basis
of Aquinas´ natural law and that is why the Catholic Church today
maintains a strict adherence to the belief that Homosexulaity,
contraception, abortion, masturbation or any other sexual act not aimed
at procreation is unnatural, sinful and therefore immoral. Any one of
these actions is to confuse the ´apparent good´ of sexual
gratification with the ´ideal good´ of reproduction.

22. Carry out lesson plan card sort
exercise
Give out essay plans