The document discusses the concept of natural law as the basis for ethical thinking in Catholicism. It stems from Aristotle and was given philosophical expression by St. Thomas Aquinas. Natural law holds that morality is based on human nature and that actions are right or wrong depending on whether they fulfill or contradict human nature. For Aquinas, human nature is understood in terms of primary purposes like living, working, reproducing, and worshipping God. Secondary precepts then provide more details on how these purposes are fulfilled. This approach is being debated today as views on human nature have evolved.

1. NATURAL LAW
The basis of ethical thinking in the Catholic Christian tradition –
stemming from Aristotle and given philosophic expression by St.
Thomas Aquinas
These charts prepared by Dr. Peter Vardy
Vice-Principal, Heythrop College, University of London

2.  “There is no good or evil, there is only power and those with
the will to use it.” (Lord Voldermort in ‘Harry Potter’ –
based on Nietzsche!)
IS THIS RIGHT??
 ETHICS IS, PARTLY AT LEAST,
ABOUT WHETHER THIS IS TRUE AND
THE NATURAL LAW TRADITION
WOULD REJECT VOLDERMORT’s
VIEW…

3. FOUNDATIONS FOR
CHRISTIAN ETHICS
The main alternative sources
for ethical principles are:
 THE BIBLE
 NATURAL LAW
 PROPORTIONALISM
 SITUATION ETHICS

4. The Bible as a basis for Christian Ethics
 Christians vary as to the status they give to the
Bible – between ‘fundamentalists’ and ‘liberals’
(to use very loose terms)
 So much depends on how a text is read and the
context in which it was written.
 Some things are clearly forbidden by the Bible
which are clearly contextual – e.g. not wearing
garments made of mixed fabrics.
 Other things are more debatable such as
prohibitions against homo-sexuality. Some
Christians maintain that the Bible clearly says
that this is wrong, others (such as Rowan
Williams the Archbishop of Canterbury) argue
that the Biblical text needs to be read in context.
 These slides deal with the NATURAL LAW
TRADITION which is the basis for ethics in
Catholicism.

5. Claudio and Isabella
by Holman Hunt
 Claudio can only be released if
Isabella is willing to lose her virginity
to the local Lord.
 He says that death is a terrible thing,
but her reply is that so is a life of
shame.
 It illustrates the basic difference
between a Natural Law, deontological
approach and a situationist approach.
Are certain actions wrong in
themselves or does the situation have
to be taken into account when
determining whether or not an action
is right?

6. ORIGINS OF THE DEBATE
 The origins of much ethical thinking
today lie in the philosophy of the great
Greek thinkers: Plato and Aristotle.
 Whereas Plato’s philosophy saw this
world as imperfect, a shadow of the true
reality represented by the unchanging
and perfect ideas of ‘Forms’, Aristotle
was concerned largely with this world.
 St. Thomas Aquinas was to use
Aristotle’s thinking and this became the
intellectual basis for Catholic ethics.

7. PLATO – in motion
(walking) indicating the
changing state of the
Universe with the
‘TIMEAUS’ and his
finger pointing upwards
to the Forms.
ARISTOTLE – feet firmly
planted on the ground,
the ‘ETHICS’ flat and
hand extended to
emphasise science and
observation of this
world.

8. Plato’s Forms
 Plato considered that MATTER is
everlasting – it is inherently chaotic and
disordered.
 THE FORMS are the perfect exemplars of,
for instance, truth, beauty, justice and,
above all, THE GOOD. They exist beyond
time and space and can never change and
never cease to exist.
 If we see different examples of beauty,
these are all called beautiful because they
all resemble or participate in the perfect
Form of Beauty which exists beyond time
and space as the perfect idea of beauty.
 At times, Plato seems to consider there is a
Form for everything in the world.

9. Aristotle rejected Plato’s Forms
 Aristotle totally rejected Plato’s idea of the
Forms – particularly the Form of the
Good.
 He considered that no-one would be
helped by knowing what this was. A
doctor needs to know in what health
consists or a general what victory
represents.
 So, for Aristotle, philosophy begins with a
study of the world – with a study of ends
or purposes.

10. THIS WOMBAT IS
GOOD NOT BECAUSE
IT IS MORALLY
GOOD – IT IS GOOD
BECAUSE IT
FULFILLS THE
NATURE OF A
WOMBAT.
FOR ARISTOTLE,
EVERY SPECIES HAS
A DISTINCT
NATURE – AND THE
SAME APPLIES TO
HUMAN BEINGS.

11. WHAT IT IS TO BE GOOD
 Central to Aristotle’s approach is that a
tree, plant, animal or human is good if it
fulfils its nature – if it becomes what it is
intended to be.
 A good dandelion, kiwi fruit, kangaroo or
box jellyfish are good because they fulfil
their nature.
 To a human, a box jellyfish may appear
bad, but this is not Aristotle’s position. It is
good if it does what a box jellyfish should
do.

12. Study and Empiricism
 By studying something, one can
eventually come to understand what
its ‘form’ is – and its form is related
to its ‘end’ or function. So Aristotle is
an empiricist. He was the first
scientist studying things to
understand their nature.
 Take an axe – its function would be
the power to chop. If it should lose
this ability and if this could not be
restored, then it would no longer be
an axe.
 Take an eye – its function is to see.
But if the eye loses its function (for
instance it is in a bottle), then it is no
longer an eye.

13. Potential
 Aristotle defined what things were in
two ways:
 1) What they were physically, and
 2) What they had potential to do.
 Everything in the universe has
potential and part of working out
what a thing is depends on knowing
its potential.
 The same applies to human beings.
We share with animals the potential
to move, communicate and
reproduce, but there is more to being
human than this.

14. The drive to perpetuate
 Everything seeks to perpetuate itself
– Aristotle says there is a force in all
things for the preservation of their
form. Reproduction is an example of
this (this is a very modern view and
fits in well with evolution – e.g.
Richard Dawkins).
 Each animal or plant has a natural
drive to perpetuate their form and
they do this by producing offspring.
Their form is transmitted through
reproduction – this can fit well into
modern ideas of genetics.

15. All humans desire by their
nature desire to know.
 This is vital for Aristotle: all human
beings seek understanding. It is an
essential part of what makes them
human – for Aristotle, this
understanding is itself Divine.
 When humans study the natural
world they are also coming to
understand their place in nature.
They are thus also coming to
understand themselves.
 The Gaia hypothesis echoes this
today – we are part of the whole of
nature, not set apart from it.

16. Potentiality and Actuality
 Aristotle makes an important
distinction between potentiality and
actuality.
 An axe has a potential to cut, but
this potentiality has to be
actualised.
 Similarly a human being has the
potential to run, to love or to know –
but this does not mean that these
are actualised. A person can go
through life and not actualise any of
these potentialities.

17. Potentiality to actuality
 A person has the potential to learn.
 When learning, one is actualising
this potential – ignorance is
replaced by knowledge
 When using this knowledge we
reinforce what we have learned.
 Humans have the potential to hear
passed on by their parents. When
they do hear, they are actualising
this potential. So the hearer is active
when she hears.

18. Jonathan Lear and Kermit
 Jonathan Lear in ‘Aristotle: The desire
to understand’ (p. 118) gives the
following example:
 1. Kermit as an embryo (bare
potential – to develop into a tadpole,
then into a frog, then into an active
adult)
 2. Kermit the tadpole (higher level
potential to become a frog and then a
mature, adult frog)
 3. Kermit the mature frog – asleep
(now fully actual at the first level as
there is a fully actual, living body)
 4. Kermit actively living his mature
life (now fully actualised not just as a
body but using its capacities)

19. Human potential
 An embryo has the potential to become a
foetus
 The foetus has the potential to become a
baby
 The baby has the potential to become a
child
 The child has the potential to become an
adult
 The child and adult have the potential to
learn and to know (this will be the life of a
student)
 The adult has the potential to apply this
knowledge (this will be the life of a busy,
active adult, making money, being a
doctor, lawyer, worker, family
man/woman, etc.)
 The adult has the potential to become a
thinker and to understand…… (not
everyone fulfils this potential!)

20. THE HUMAN ABILITY TO
UNDERSTAND
 Aristotle considers that humans are alone
among animals in having the potentiality to
understand the nature of other things –
humans can apprehend something of the
form of another thing, not just its sensible
form (notice that this is totally different
from Plato’s ideas of the Forms)
 The universe, Aristotle considers, is capable
of being understood (it is intelligible) and
humans have the potential to understand it.
This led to science and scientific enquiry.
 As humans come to understand the world,
they also learn about themselves – that it is
part of their nature to understand. THIS IS
PART OF WHAT IT IS TO BE HUMAN.

21. Aristotle and Kermit
 Aristotle, as a human being, has the
capacity to learn about frogs.
 When he does learn, he actualises this
potentiality as he acquires knowledge and
learns of the ESSENCE of Kermit the
frog. The essence is not something
material, it is the very nature of frogs.
 However he then has an even higher level
capacity – the ability to use this
knowledge.

22. DELIBERATION
 Most of us today think that, as human
beings, we deliberate on what we are
going to do with our lives and what their
purpose is. ARISTOTLE REJECTS THIS.
 Aristotle holds that the telos or purpose of
our lives comes from our human nature.
Deliberation is confined to how this given
purpose is to be fulfilled. The purpose itself
is a ‘given’.
 So, for Aristotle, we do not choose our
purpose. We can just make good or bad
choices about how this purpose to be be
fulfilled.
 The good life, Aristotle considered, is the
life of happiness, and happiness is greatest
when we are philosophers.

23. St. Thomas Aquinas
 Aquinas was probably the
greatest philosopher and
theologian of the last 2000
years. Writing in the University
of Paris in the C13th, he used
the philosophy of Aristotle -
which had been kept alive in the
great Islamic centres of learning
- to make sense of Christian
morality and theology.
 In particular, morality was, he
claimed, based on Aristotle’s
argument that all human beings
share a common human nature.

24. All human beings seek the good…
 Aquinas considered that all human beings
seek the Good. In other words they all
seek what they think is good for them.
 However they can be mistaken. They may
seek an APPARENT GOOD rather than the
REAL GOOD. Thus a thief what she thinks
is good but she makes a mistake – she
pursues what appears to be good and not
what is really good.
 The task of moral philosophy is to work
out what is REALLY GOOD for human
beings, rather than what APPEARS TO BE
GOOD.

25. WHAT IS REALLY GOOD?
 For Aquinas, what is ‘really good’ is
fulfilling the potential of our common
human nature.
 Those actions which help us to become
MORE FULLY HUMAN – more what we are
capable of being – are good. VIRTUE
ETHICS COMES IN HERE.
 Those actions which lead us to be LESS
THAN FULLY HUMAN – which lead us away
from what we are capable of being – are
morally wrong.

26. PRIMARY AND SECONDARY
PRECEPTS
 Aquinas defined what is to be human
in terms of purpose. The general
purpose of being human is to ‘LIVE,
WORK, REPRODUCE, EDUCATE
CHILDREN, HAVE AN ORDERED
SOCIETY AND WORSHIP GOD’.
 All these came from Aristotle except
for the worship of God which was
added by Aquinas.
 However it is at the next level – of
secondary precepts -that the detail is
worked out

27. ‘Reproduction’ is held by Aquinas to be one
of the primary purposes of human life…
 At the level of secondary precepts the
detail is worked out…
 WHAT IS THE PURPOSE OF GENITALIA????
 Aquinas answered ‘reproduction’
 Once this answer is given, then any use of
genitalia for any other purpose is
‘intrinsically evil’ – it is evil in and of
itself.
 So masturbation, sex using contraception,
sex with an animal, homosexuality, etc.
will all be INTRINSICALLY EVIL ACTS….
i.e. these are acts which are morally
wrong (or evil) in themselves.

28. So, for instance, there are two reasons why the Catholic
Church (basing its teaching on Natural Law) would reject
I.V.F.
 Two ‘intrinsically evil acts’ are involved in
I.V.F. – WHAT ARE THEY??
 1) The husband has to masturbate to
produce the sperm necessary to fertilise
his wife’s eggs… NOTE he cannot say that
he is doing this for a good purpose as THE
ACT ITSELF IS INTRINSICALLY EVIL.
 2) I.V.F. involves taking 15 –20 eggs out
of the woman, fertilising them and re-
implanting 2 or 3. This means killing the
unused, fertilised eggs. In the Catholic
tradition, since life may begin at
conception this means killing people…..
(note the reference to ‘may begin at conception’. The Church’s
Magisterium says that there can be no certainty when life begins but,
because of the danger of being in error, it is right to treat life as beginning
at conception).

29. Challenges to Natural Law
 Perhaps all human beings do NOT share a
common human nature – genetics may
indicate this.
 Perhaps Aquinas’ understanding of human
nature is mistaken
 Perhaps actions are not right or wrong in
themselves but depend on context
 Perhaps the Natural Law approach lacks
flexibility
 The Natural Law approach leaves no room
for love as a factor in ethics.

30. AMENDING NATURAL LAW
 It is possible to remain faithful to the Natural
Law methodology but to challenge Aquinas’
understanding of human nature.
 Human understanding of sexuality, physiology,
psychology, etc. has increased enormously.
Perhaps what is needed today is a new
understanding of human nature.
 WHAT IS IT TODAY TO LIFE A FULFILLED
HUMAN LIFE? This question is as relevant
today as ever in the past…. (Peter Vardy argues for this approach in
‘The Puzzle of Sex’ [Harper Collins] and ‘Being Human’ [DLT]) and it is crucial to the debate
today.

31.  THE MAJOR DEBATE TODAY
AMONGST CATHOLIC
MORAL THEOLOGIANS

32. THE MAJOR DEBATE TODAY
 ‘Perhaps the most divisive debate in
contemporary Catholic moral theology
concerns the existence and grounding of
universally binding moral norms. The
Scholastic moral theology of the manuals
held that certain acts were intrinsically
evil on the basis of the act itself,
independent of the intention,
circumstances and consequences.
Revisionists maintain that the evil in acts
such as contraception or even direct
killing is not moral evil but... premoral
evil which can be justified for a
proportionate reason.‘John Macquarrie's 'A
new Dictionary of Christian Ethics' (p. 392):

33. The Major Debate in Catholic moral
theology today
 To put this another way, the issue is
whether certain acts (for instance
abortion, euthanasia, theft, lying,
etc.) are
 1) Always wrong in themselves
(they are ‘intrinsically evil’) or
 2) Whether it can sometimes be the
morally right thing to do to perform
an act which, in itself, is wrong but
is justified by a proportionate
reason (this is a reason of sufficient
gravity)

34. PROPORTIONALISM
 This is based on the Natural Law approach and
stems from the Catholic tradition. Many Catholic
moral theologians maintain that it is faithful to
this tradition.
 It holds that there ARE firm more rules – BUT
circumstances have to be taken into account in
deciding on the nature of an act. Acts cannot be
defined without reference to the circumstances
and intentions behind the acts. This means that
an act which may appear to be lying is recognised
as being more complex to define if there is a
proportionate reason which would justify this.
 Proportionalism is held to be faithful to the
mainstream Catholic Christian tradition in a way
in which the strict deontological approach is not.
 An action may be objectively WRONG but morally
RIGHT and that another action may be objectively
RIGHT but morally WRONG

35. Proportionalism contd.
 A distinction has to be made between acts
which are good and acts which are right -
and this distinction, proportionalists
maintain, is often not made.
 A person may have a good intention but
may be able to achieve that intention only
through an act which is considered to be,
in itself, evil.
 The proportionalists hold that it is possible
for an action, in itself, to be wrong, whilst
based on the actual situation in which the
action is done the action may be morally
right.

36. Circumstances have to be
taken into account
 Proportionalists seek the right thing to do in the
particular circumstances.
 Unlike advocates of situation ethics, they affirm
that there are nonmoral goods and evils, but they
maintain that the circumstances need to be taken
into account in deciding whether a nonmoral evil
is also a moral evil. Killing, theft or contraception
(if one is a Catholic) MAY be morally good in
certain circumstances.
 Those who advocate Situation Ethics and
supporters of Proportionalism both maintain that
agape is the only criterion for moral goodness or
badness. HOWEVER PROPORTIONALISM REFUSES
TO ACCEPT THE SITUATION ETHICIST'S VIEW
THAT LOVE CAN MADE AN ACTION RIGHT.

37. PROPORTIONALISM CONDEMNED
 Proportionalism has been condemned by the
Catholic Magisterium and by Pope John Paul ll.
Some Bishops therefore consider that it is a
position that should not be taught in any Catholic
school.
 The logic of this condemnation is compelling as it
opens the door to individuals deciding to go
against the teaching of the Church when they
consider that a proportionate reason justifies
this. Whether this condemnation is faithful to the
mainstream Catholic tradition is a matter of
debate amongst Catholic moral theologians.
 This also raises the issue of CONSCIENCE and
INFORMED CONSCIENCE. To what extent can
individual conscience allow someone to act
against Church teaching?