St. Thomas Aquinas (1224-1274) was a significant medieval theologian-philosopher who integrated Aristotelian philosophy with Christian theology, producing influential works like the 'Summa Theologica.' He formulated the doctrine of natural law, asserting that human law should align with eternal law derived from divine reason. Aquinas emphasized that political governance is essential for human society and morality is founded on the pursuit of good, ultimately leading to a nuanced understanding of justice and ethics within a theological framework.

2. St. Thomas Aquinas (1224-1274 )
Aquinas came from a noble family from Naples.
He joined the Dominican order against his family’s wishes.
Aquinas studied with Albert the Great in Paris and
participated in the Aristotelian revival of the Middle Ages.
He was canonized and became a saint in 1323.
Resisting the temptation of a prostitute and the discovery of
Herring at night were the miracles used to justify his
sainthood.
Aquinas’s extensive corpus of scholarship is perhaps a
greater miracle than those mentioned above.

4. • Known as the greatest
Christian medieval
theologian-philosopher, he
single-handedly stemmed the
tide of Islamic Aristotelianism
into Europe
• His friends playfully called
him “the dumb ox”
• He produced over ninety
works in a little over two
decades
• Summa Theologica
• Summa Contra Gentiles
• The Ways of God: For
Meditation and Prayer
• He stands at the top of the
group of thinkers known as
Scholastics
• At age 48 he suddenly
stopped writing
• Maybe he suffered a brain
hemorrhage
• Maybe he had a vision that
academic learning was not
the most important thing
• “All that I have written
seems like straw to me,” he
told a friend
• A year later, he died on the
road to a church council

5. Aquinas was dubbed “the dumb ox”
by his fellow students, for being
large and quiet. He was
apparently quiet because he was
busy thinking; he became the
Catholic church’s top theologian,
a title he still holds today, without
dispute.

6. Aquinas’s major work, the
Summa Theologica, is divided
into 4 parts.
 Prima Pars (1st Part) Existence and
Nature of God
 Prima Secundae (1st Part of the 2nd
Part) Happiness, Psychology,
Virtues, Law (Human, Natural,
Divine)
 Secunda Secundae (2nd Part of the
2nd Part) The virtues in detail
 Tertia Pars (3rd Part) Christian
Doctrine

7. The political philosophy of Thomas Aquinas,
along with the broader philosophical teaching of
which it is part, stands at the crossroads between
the Christian gospel and the Aristotelian
political doctrine.

8. During the Middle Ages, many of Aristotle’s works were
lost to Western Europe, beginning in the first few
centuries AD.
Aquinas merged Aristotle with Christianity after the
recovery of his philosophy via Muslim scholars in the
12th and 13th century.
The ‘purposiveness’ or ‘end-directedness’ of nature in
Aristotle is identified by Aquinas with God’s purposes.

9. The Islamic philosopher
Averroes (Ib’n Rushd) had
tailored Aristotle’s teachings
so that the beliefs in
creation, the immortality of
the soul, and the unity of
truth were discarded
• Averroes influenced many
in Christian academia
Aquinas took on the task
of studying Aristotle for
himself, and building a
Christian worldview to
counter that of the
Averroists

10. Unlike his medieval Jewish and Islamic
counterparts, Aquinas does not have to reconcile
Aristotelianism with a concrete political and legal
code specified in the sacred writings of his religion.
.As far as he is concerned, God no longer requires
people to live according to the judicial precepts of
the Old Law (Summa Theologiae [hereafter ST], I-
II, 104.3), and so the question of formulating a
comprehensive Christian political teaching that is
faithful to biblical principles loses it urgency if not
its very possibility.

11. These observations perhaps explain why
Aquinas, whose writings nearly all come in
the form of extremely well organized and
systematic treatises, never completed a
thematic discussion of politics.
His letter On Kingship(written as a favor to the king of
Cyprus) comes closest to fitting the description of a
political treatise, and yet this brief and unfinished
work hardly presents a comprehensive treatment of
political philosophy.

12. Even his commentary on Aristotle's Politics is less
than half complete, and it is debatable whether this
work is even intended to express Aquinas' own
political philosophy at all.
Although it is not expressed in overtly political
works, Aquinas' thoughts on political philosophy
may be found within treatises that contain
discussions of issues with far reaching political
implications.

13. In his celebrated Summa Theologiae, for instance,
Aquinas engages in long discussions of law, the
virtue of justice, the common good, economics, and
the basis of morality.
Even though not presented in the context of a
comprehensive political teaching, these texts provide
a crucial insight into Aquinas' understanding of
politics and the place of political philosophy within
his thought.

14. Aquinas was primarily a Christian theologian.
He viewed human wisdom as structured like a pyramid
with the sciences of ethics and politics at its base with
philosophy above and theology at its apex.
Natural philosophy are not contradictory but
complementary.
Faith and reason are valid in their own realms.
Aquinas’ scholastic method integrates Aristotle’s
teleological view of nature into the biblical theology of
creation and Christian salvation.

15. Theology
Philosophy
Ethics &Politics

17. "The unseen things of God are visible through His
manifest works."
Rom. I: 20
Aquinas was inspired by this passage to examine God’s
works and prove to the skeptics that there is a God!

18. The Mystery of Creation

19. Consider a bouncing
ball. How did the ball
start bouncing? Did it
fall and if so what
caused it to fall? What
started all the action?
The First Proof: The Prime Mover
According to Aquinas,
“it is necessary to go
back to some first
mover, which is itself
moved by nothing---
and this all men know
as God.”

20. Consider yourself and your
family history. You came to be
because of your parents and
your parents came to be
because of their parents and
so on. But where does it begin?
Aquinas explains, “if the chain
were to go back infinitely,
there would be no first cause,
and thus no ultimate effect,
nor middle causes, which is
admittedly false. Hence we
must presuppose some first
efficient cause---which all call
God.”

21. Consider things that exist beyond the realm of human control. How
did trees, animals, mountains, stars, and the sun come to exist?
What caused these things to exist? If it was a mere accident what
existed before the universe? If nothing, then nothing can come from
nothing.
The Third Proof: Possibility and Necessity
Thus, Aquinas argues, “there must be presupposed something
necessarily existing through its own nature, not having a cause
elsewhere but being itself the cause of the necessary existence of
other things---which all call God.”

22. Consider the notion that
there are varying degrees of
love, goodness, and
perfection. Consider the
concept of heat. There are
certainly varying degrees of
heat.
Aquinas points out, “fire,
which is the greatest heat, is
the cause of all heat.” The
cause of the greatest love,
goodness, and perfection is
who we call God.

23. Aquinas saw this ordered structure and argued,
“there is something intelligent by which all natural
things are arranged in accordance with a plan---and
this we call God.”
The Fifth Proof: The Cosmos
Examine the natural
world around you.
Although it appears to
be chaotic at times,
nature is very
structured. Weather
systems, oceans, the
solar system, time, it
all has structure. Who
is responsible for this
structure? Who could
have designed such a
plan?

25. "Things are in motion, hence there is a first mover.
Things are caused, hence there is a first cause.
Things exist, hence there is a creator.
Perfect goodness exists, hence it has a source.
Things are designed, hence they serve a purpose.“
-St. Thomas Aquinas
(1224 – 1274)

26. Political rulership must be carried out under law and the
ruler should keep the laws he makes for others.
Aquinas describes the essence of law:
Law is a rule and measure of acts whereby man is
induced to act or is restrained from acting: for lex (law)
is derived from ligare (to bind), because it binds one to
act.
Now the rule and measure of human acts, as is evident
from what has been stated above, since it belongs to
the reason to direct the end, which is the first principle
in all matters of action according to the Philosopher
(Aristotle).

27. Eternal LawNatural LawDivine Positive LawHuman
Positive Law
 Eternal Law – Divine reason and wisdom comprise an eternal law
– a law governing the whole creation, a law not made but eternally
existing and therefore unknowable to humans entirely, yet the
source of all true law on earth.
(Eternal law comes from God and is unchanging).
 Natural Law – The practical reflection or sharing in “eternal
reason” that provides humans with objective, changeless, universal
rules or general principles of action for ethical and political life.
(Natural law is eternal law that can be known to humans)

28. Divine Law – The revealed
truths such as the ten
commandments and the Sermon
on the Mounts that supplement
and corrects human fallibility
and frailty.
(Divine Positive law is the
part of eternal law revealed
through the scriptures).
Human Law – True law that is
derived from natural law. A rule of
state that is at odds with natural
law is no law at all.
(Human positive law is the
laws made by the state )

29. The Order of Natural Law
First Principle: Do good and avoid evil.
For example preserving life, caring for
children, knowing the truth about God, not
harming others, helping the poor and the
sick, shunning ignorance, etc.
Second Principle: How to act based on the first
principle.
For example the enforcement of the law,
making of laws, functioning of society.

30. Aquinas' celebrated doctrine of natural law no
doubt plays a central role in his moral and
political teaching. According to Aquinas,
everything in the terrestrial world is created by
God and endowed with a certain nature that
defines what each sort of being is in its essence.
A thing's nature is detectable not only in its
external appearance, but also and more
importantly through the natural inclinations
which guide it to behave in conformity with the
particular nature it has.

31. Aquinas explains that the entire universe is
governed by the supreme lawgiver par
excellence: "Granted that the world is ruled by
Divine Providence...the whole community of the
universe is governed by Divine Reason."
Even though the world governed by God's
providence is temporal and limited, Aquinas
calls the law that governs it the "eternal law." Its
eternal nature comes not from that to which it
applies, but rather from whom the law is derived,
namely, God

32. As Aquinas explains, "the very idea of the government of
things in God the Ruler of the universe, has the nature of
a law. And since Divine Reason's conception of things is
not subject to time but is eternal, according to Prov. viii,
23...this kind of law must be called eternal." (Ibid.).
Because the rational creature's relation to the eternal law
is so different from that of any other created thing,
Aquinas prefers to call the law that governs it by a different
name. Instead of saying that humans are under the eternal
law, therefore, he says they are under the natural law, and
yet "the natural law is nothing else than the rational
creature's participation of the eternal law"

33. Unlike Aristotle, Aquinas did not believe that the state leads people
to their greatest potential. The state is subordinate to the Catholic
church who is in charge of moral matters on Earth. Therefore an
unjust law does not have any binding force. Such laws are an act of
violence against the people of the state.
Aquinas defines
human law as “the
ordinance of
reason for the
common good,
proclaimed
publicly by a ruler
who has care for
the community”.

34. Aquinas, then, has a value-based ethical theory. The rightness or
wrongness of particular actions is determined by how those
actions further or frustrate the goods.
Certain ways of acting are “intrinsically flawed” or “unreasonable”
responses to these human goods.
Like Aristotle, Aquinas seems sure there can be no formula
provided to determine what action is right or wrong in all
particular cases.
Prudence (practical wisdom) is required for the most part, if not
always, to determine if a given act is intrinsically flawed or not.

35. Aquinas’s first principle of morality is:
 Good should be done, and evil avoided
We are by nature inclined toward the Good, according to
Aquinas, but we cannot pursue the good directly because it
is abstract—we must pursue concrete goods which we know
immediately, by inclination. Those goods are:
 Preservation of life
 Procreation
 Knowledge
 Society
 Reasonable Conduct

36. The political condition is a natural condition of human
beings as part of creation.
Aquinas states:
Thus the goodness which in God is simple and
unique is found in countless and differentiated
creatures. Consequently it is the entire universe
which shares perfectly the goodness of God and
represents it more than one creature by itself.
Human beings are partners with God and politics is
necessary even if there was no fall from the Garden of
Eden.

37. Aquinas’ reflections on human mutual dependence:
Nonhuman animals have specific natural defenses (such
as claws), whereas humans must rely on reason for their
survival.
Human co-creation requires human cooperation and
cannot be done by single individuals with their limited
talents.
The power of speech show that solitary existence is
inappropriate (“nature does nothing in vain”); speech
and language provide the mans for interpersonal
projects.

38. Aquinas argues humans must achieve the humanization of
the world and eternal salvation and this entails a principle
of government within society.
If it is natural for human beings to live in society, then it follows
that there must be regulation of society. For not human group
can long endure if each person sought only his individual ends.
One of them would have to provide for the common interest, just
as an organism would break apart unless it had some controlling
power in it which worked for the good of all bodily parts….

39. Humans require political rule for social survival.
Humans should be put under the rule of those providing
for the common interest or common good.
The king or government exists to prevent chaos.
Original sin leaves humans wounded, fallible, and frail
though not vitiated or corrupted.
Political institutions foster knowledge, culture, and virtue
and permit humans to pursue their ultimate end, which is
the enjoyment of God.

40. • Philosophers who follow
Aquinas’ teachings are known
as Thomists
• Pope John Paul II (Fides et
Ratio)
• Etienne Gilson (The Spirit of
Medieval Philosophy and The
Christian Philosophy of St.
Thomas Aquinas)
• Norman Geisler (Baker
Encyclopedia of Christian
Apologetics, and over 50 other
books)
• Catholic hospitals follow
Aquinas’ ethics
• Frances Schaeffer joins
Ronald Nash in being a
critic of some aspects of
Aquinas’ philosophy
• “In Aquinas’ view the will
of man was fallen, but the
intellect was not. . . . Out
of this, as time passed,
man’s intellect was seen as
autonomous.” – Escape
from Reason, p. 211
40

41. “The highest manifestation of
life consists in this: that a
being governs its own actions.
A thing which is always
subject to the direction of
another is somewhat of a dead
thing”.
-Aquinas, Thomas. 13th
Century.