Thomas Aquinas draws on Aristotle's philosophy of the four causes and Plato's idea of the good to develop his theory of natural law. For Aquinas, God is the prime mover and source of all goodness in the world. Natural law refers to humanity's shared rational nature that inclines us towards virtue and allows us to discern good from evil. As rational beings with free will, humans have a participation in eternal law and are directed by reason towards our proper ends or goods.

2. NATURAL LAW
 THOMAS AQUINAS
- the CONTEXT of the CHRISTIAN STORY
- the CONTEXT of AQUINAS’s ETHICS
 the GREEK HERITAGE
- NEOPLATONIC GOOD
 the IDEA of the GOOD
 the GOOD and the ONE
 ARISTOTELIAN BEING and BECOMING
- the FOUR CAUSES
- SYNTHESIS

3. NATURAL LAW
 the ESSENCE and VARIETIES of LAW
- ESSENCE
- VARIETIES
 NATURAL LAW
- in COMMON with OTHER BEINGS
- in COMMON with OTHER ANIMALS
 UNIQUELY HUMAN

4. NATURAL LAW
 idea of the GOOD
 material cause
 final cause
 formal cause
 efficient cause
 potency
 act
 human law
 natural law
 eternal law
 divine law

5. Therefore, thou shalt love the
Lord thy God, and keep His
charge, and His statutes, and
His judgement, and His
commandments,alway.
(Deuteronomy 11:1,KJV)

7. Background
Thomas Aquinas 1225-1274 hailed as a
Doctor of Roman Catholic Church, a
dominican friar who was a preeminent
intellectual figure of the Scholastic Period
of the middle ages, contributing to the
Doctrine of the Faith more that any other
Figure of his time.

8. Background
His Summa Theologiae, his magnum opus,
is a voluminous work that comprehensively
discusses many signifant point in Christian
Theology. He was canonized in 1323.

9. The context of the Christian Story
Maintained and elaborated that “we” by God
in order to return to Him. The structure of his
magnum opus – the Summa Theologiae
follows this tragectory

10. The context of the Christian Story
First part speaks of God
Second part deals with man and the
dynamic human life
the third part focuses on Jesus as our Savior

11. The context of Aquinas’s Ethics
How, our pursuit of happiness, we direct our
actions toward specific ends and how emotions
(passions) are involved in this process?
How our actions are related to certain
dispositions (habits)?

12. The context of Aquinas’s Ethics
How we develop either good or bad habits with
a good disposition leading us toward making
moral choices thereby contributing to our
moral virtue?

13. The context of Aquinas’s Ethics
The Christian life is about developing the
capacities given tous by God into a disposition
of virtue inclined toward the good.

14. The context of Aquinas’s Ethics
Within us is a conscience that directs our moral
thinking (not intuition or gut feeling)
A sense of right and wrong in us that we are
obliged to obey. But this must be informed,
guided and grounded in an objective basis for
morality

15. The context of Aquinas’s Ethics
We are called to heed the voice of conscience
We are enjoined to develop and maintain a life
of virtue. (virtuous)
We need a basis for our conscience to be
properly informed

16. The context of Aquinas’s Ethics
We need clearer guidepost on whether certain
decisions we make lead us towards virtue or
vice.
The need for clearer basic ethics to direct our
sense of what is right and wrong is referred to
by Aquinas as the Natural Law.

17. Neoplatonic Good
The central belief of the Christian Faith - God
Creates – He cares for and thus governs the
activity of the universe and of every creature
this has been shaped and defined by an idea
stated in the work of the ancient Greek
philosopher – Plato

18. Neoplatonic Good
Plato’s most compelling and enduring idea: the
notion of a supreme and absolutely
transcendent good
He envisioned the ideal society through his work
The Republic

19. Neoplatonic Good
It provides an objective basis and standard for
the striving to be moral.
“Why should I bother trying to be good?”
“Why cannot good be whatever I say it is?

20. Neoplatonic Good
Plato’s answer is placed on the mouth of the
main character of The Republic
“..the good is real and not something that one
can pretend to make up or ignore” - Socrates

21. The Idea of the Good (p45)
The enigmatic passage of the idea of the good
which is prior to all being and is even the
cause of all beings becomes the source of
fascination and inspiration of later thinkers -
neoplatonists.

22. The Good and the One(p46)
Neoplatonists caused Idea of the Good to
become The One and The Beautiful
The Platonic idea of the good continued into the
era of Christian Middle Ages, thought anew in a
more personal way as a creative and loving God

23. The Four Causes
Any being can be said to have four causes -
Aristotle
1. Material cause embraces the concept that any
being is corporeal, composed of certain materiality
or physical stuff, inidividuated, unique individual as
is made up of particular stuff.

24. The Four Causes
2. The shape that makes a being a particular
kind is called its form, and is referred to as the
formal cause
3. It is thought that there is always something
that brings about the presence of another being,
and this is referred to as efficiency cause.

25. The Four Causes
4. A being has an apparent end goal and
Aristotle referred to it as its final cause
Cause is that out of which a thing comes to be
ad which persists

26. The Four Causes
Cause is the form or the archetype, the
statement of the essence and its genera
Cause if the primary source of the change or
coming to rest and what makes of what is made
and what causes change of what is changed

27. The Four Causes
Cause is the sense of end or that for the sake of
which a thing is done
The four causes differ from one another in that
some are activities, others instruments.

28. The Four Causes
Aristotle explained the process of becoming or
the possibility of change that takes place in a
being
The principle of Potency and Act is that a being
carry within itself certain potentials, but these
require being actualized.

29. The Significant contribution of Aristotle
to the picture given to us by Aquinas
The process of becoming – or change – is the
understanding of beings, how they are and how
they become or what they could be

30. The ideas of transcendent good prior to all being
in the form of the good and loving God, Himself
the fullness of being and of goodness
God is that which essentially is and is
essentially good

31. All beings are only possible as participating in
the first being, which is God Himself and His act,
like an emanation of light, is the creation of
beings.
God is the First Efficient Cause in that from
which all beings come

32. It is God’s will and love that are the cause of all
things in every existing thing.
Creation therefore is the activity of the
outpouring or overflowing of God’s goodness
and this makes each being in some sense good.

33. The goodness possessed by beings remains
imperfect for only God in the fullness of His
being and goodness is perfect.
God did not create beings to remain imperfect
and to stay that way. God, in His infinite wisdom
directs how we are to arrive at our perfection.

34. Divine providence is a notion how beings are
properly ordered and even guided toward their
proper end which is to reach the highest good, is to
return to the divine goodness itself.
Divine goodness is the end of all actions. All
things come from God and are created in order
to return to Him

35. The presence of capacity for reason is the prime
characteristic of the kind of beings we are, and how
this is the very tool which God had placed in our
human nature as the way to our perfection and
return to Him.

36. The whole work of creation as divine reason
governing a community toward its end and how
their acts are to lead them to their end shall be
thought of in terms of law

37. As rational beings, men have free will, through our
capacity for reason, we are able to judge between
possibilities and to choose to direct our actions in
one way or the other
ESSENCE
Our actions are directed toward attaining ends or
goods that we desire

38. We act in pursuit of our own end or good with
regard for other people’s ends or good. Since we
are not an isolated being, that is we belong in a
community, we consider what is good for the
community as well as our won good. This is called
the Common Good
ESSENCE

39. The determination of the proper measure of our
acts can be referred to as law
ESSENCE
A law is concerned with the common good
A law is necessary to be communicated to the people
involved in order to enforce them and better ensure
compliance. This is referred to as promulgation

40. Eternal Law is an assertion that the divine wisdom
that directs each being toward its proper end. It
refers to what God wills for creation and how each
participant is intended to return to Him.
VARIETIES
Does irrational creatures part of this eternal law?

41. The unique imprint upon us is the capacity to think
about what is good and what is evil, and this is
Eternal Reason, whereby it has a natural inclination
to its proper act and end, and this participation of
the eternal law in the rational creature is called the
Natural Law
VARIETIES

42. The unique imprint upon us is the capacity to think
about what is good and what is evil, and this is
Eternal Reason, whereby it has a natural inclination
to its proper act and end, and this participation of the
eternal law in the rational creature is called the
Natural Law – determining the rule and measure that
should direct our actions.
VARIETIES

43. While reflecting on our human nature will provide us
the precepts of the natural law, these are general.
There should have to be more concrete in the actual
operation of human acts. For this reason, there is
also Human Law
VARIETIES

44. Human law refers to instances wherein human
beings construct and enforce laws in their
communities.
VARIETIES
Human law needs to be assessed in its validity or
invalidity; whether or not it conforms to the natural
law.

45. Good things has a nature of an end, and evil, the
nature of the contrary,
Man has an inclination for good in accordance with
the nature of which he has in common and warding
off its obstacles.

46. There is in man an inclination to things that pertain to
him more specially, according to that nature which he
has in common with other animals, and in virtue of
this inclination, those things are said to belong to
natural law – which nature has taught to all animals

47. There is in man an inclination to good, according to
the nature of his reason, which nature is proper to
him.

48. Human beings are both unique and at the same time
participating in the community of the rest of creation.
Our presence in the rest of creation does not only
mean that we interact with creatures that are not
human, but there is also in our nature something
that shares in the nature of other being.
In Common with Other Beings

49. There is in our human nature. Common with other
animals, a desire that has to do with sexual
intercourse and the care of one’s offspring.
In Common with Other Animals
Any form of sexual act that could not lead to offspring
must be considered deviant. One of these is the
homosexual act

50. There is in our human nature. Common with other
animals, a desire that has to do with sexual
intercourse and the care of one’s offspring.
In Common with Other Animals
Any form of sexual act that could not lead to offspring
must be considered deviant.

51. Contraception allows sexual act to take place but
inhibit procreation
In Common with Other Animals
Homosexual act allows sexual intercourse to take
place but could not lead to offspring

52. Capacity to reason
UNIQUELY HUMAN
Being rational
Being capable of valuation