Thomas Aquinas, Treatise on Law
Date: February 23, 2009
Presenter: Nick Coccoma
Summary of Work:
Aquinas's political and legal theory is important for three reasons. First, it reasserts the value of
politics by drawing on Aristotle to argue that politics and political life are morally positive
activities that are in accordance with the intention of God for man. Second, it combines
traditional hierarchical and feudal views of the structure of society and politics with emerging
community-oriented and incipiently egalitarian views of the proper ordering of society. Third, it
develops an integrated and logically coherent theory of natural law that continues to be an
important source of legal, political, and moral norms.
Main Point of Section:
In the Treatise on Law, Aquinas concerns himself with the origins of law. He wants to know the
source of the obligation that law imposes. The questions are these: “By what warrant does the
human legislator bind the consciences of people? Doesn’t this power belong to God alone? If
people possess it, what are the limits within which they may exercise it?”
Key Ideas:
1. Source of the law is God. The root of obligation is in the divine conception of the order
proper to the universe. Human Law, to be just and morally obligating, must therefore be
rooted in Divine Law. People cannot originate the law themselves. Aquinas rejects
Divine Right theory because it contributes a divine quality to political authority. No
authority, not even the sovereign, can impose an obligation on the citizen where it is not
already latent in the nature of things.
2. Essence of Law: An ordinance of reason for the common good made by one who has
care for the community and is promulgated. (90.4)
3. Kinds of Law: A hierarchical typology of laws. * But the eternal, natural, and human
laws are all one rule progressively specified.
a) Eternal: The rational governance of everything on the part of God as ruler of the
universe (91.1). Divine Providence.
b) Natural: The participation in the eternal law by rational creatures (91.2). The
objective link between our minds and God’s mind.
c) Human (Positive): Particular applications of the law derived by reason.
d) Divine (Positive): That part of the eternal law that God positively revealed,
imperfectly to the Jews in the Law and perfectly through Christ. Helps us attain
our supernatural end.
Outline:
Question 90 : Essence of Law
“An ordinance of reason for the common good made by one who has care for the community
and is promulgated.”
a) Ordered: Law is an ordered rule and measure of acts. It ‘induces’ or obligates us to act/not act.
(Obligation is the binding of the free will to perform that act which is necessary for the
attainment of happiness; it is different than necessitating. Free will allows us to act/not act
accordingly).
b) Reason: Reason reveals the above order. The first principle of human acts is reason, because
we act primarily by recognizing and knowing the good end that the will presents to the intellect.
This is more than saying law is rational in character—Aquinas has in mind teleological
reasoning.
c) Common Good: Reason orders us toward common happiness through law, not mere individual
happiness. (This is not to say that Aquinas doesn’t care about the individual.)
d) One who has care: Law is based in the community, and making the law belongs either to all
the people or some public person who has responsibility for all the people. Thus even without
organized representative institution, the ruler is to keep the common good as her/his aim in
legislating. Corrupt governments are those that aim at the private good of the rulers rather than
the common good. In practice, Aquinas preferred a government where leaders (aristocracy)
elected by the people (democracy) assist a ruler (monarch).
e) Promulgated: In order to bind people, laws must be applied to them. This application occurs
when they are notified of the laws through promulgation. Promulgation is thus necessary for the
law to obtain force.
1st Art. Does law pertain to reason? Ans.: Law is a rule and measure of acts, whereby people are
made to act or restrained from acting. Reason is the rule of these acts, since it directs acts to an
end.
2nd Art. The Common Good as Law’s End. The first principle in practical matters (which are the
object of the practical reason) is the ‘last end’, and the last end of human life is happiness. That
happiness includes all society, so law—under the guidance of reason—serves the common good.
3rd Art. Can human reason make laws? That is, can any one person make laws for himself? Ans.:
No. To order anything to the common good belongs to the whole people or to a guardian of the
whole people.
4th Art. Law must be promulgated. On that note, the natural law is promulgated by the very fact
that God instilled it in our minds as to be known by us naturally.
Question 91: Kinds of Law
1st Art. Eternal law. A law is nothing else but a dictate of practical reason emanating from the
ruler of a community. The world is ruled by Divine Providence, meaning that it is governed by
Divine Reason. It’s ideas of the government are thus a law, and since Divine Reason is not
subject to time, this law is eternal.
Aquinas believes God’s wisdom includes a sense of the proper ordering of the whole
community of the universe. God’s Divine Reason must have a most perfect ‘idea’ of how to
order things. This wisdom is the eternal law.
2nd Art. Natural law. Rational creatures, insofar as they partake of a share of providence, have a
share of the Divine Reason, whereby they have a natural inclination to their proper acts and ends.
This participation in the eternal law is natural law. Natural law allows us to discern between
good and evil, and is an imprint of Divine Light.
Natural law is the group of universal obligations of right reason concerning the good of
nature that we should pursue and the evil we should avoid.
3rd Art. Human law. Human laws are the dictates of practical reason. They particularize the
general principles we know from the natural law. It’s the law of states, of our societies. We
cannot ‘act’ natural law since it encompasses universal obligations. We do not fully participate in
Divine Reason and thus cannot know each and every single truth. We thus look to the general
principles we have in the natural law (such as the precept ‘do good, avoid evil’) and use our
reason to draw particular conclusions (‘Help the elderly lady carry her bags’).
4th Art. Divine Law. We need this because our end is eternal happiness with God, which is
disproportionate to our natural faculties. Furthermore, divine law establishes one rule of what
one should or should not do, eliminating multiple standards. Third, divine law helps govern our
interior selves, which human law cannot. Fourth, human law does not criminalize all evils since
to do so would do away with many good things, and would hinder the advance of the common
good. Divine law thus covers and forbids all evils that human law cannot address.
5th Art. Divine law is God’s self-revelation. It comes in two forms: The revelation to the Jews,
and Christ: The Old and the New Law.
6th Art. Sin is not another law, because it deviates from the law of reason. It is rather an
inclination of sensuality stemming from the body, and has the ‘nature’ of a law.
Question 92: Effects of the Law
1st Art. To make people good. The proper effect of law is to lead people to their proper virtue,
and since virtue is that which makes its subject good, it follows that the proper effect of law is to
make those to whom it is given good.
2nd Art. To command (good acts), prohibit (bad acts), permit (indifferent acts), and use fear of
punishment to ensure obedience.
Question 94: Natural Law
1st Art. What is it? A habit? Ans.: Not essentially or properly, but insofar as we “hold something
by habit.”
2nd Art. Does it have several precepts or only one? Ans.: There is one general precept: Good is to
be done, evil avoided. This precept stems from the first principle of practical reason. Under that,
however, we have many manifestations of it flowing from the instinct for self-preservation, from
things nature has taught us (e.g., we should educate the young), and from natural inclinations of
our reason (e.g., our natural inclination to know the truth about God, to live in society, etc.). All
of these lesser precepts flow from the first.
Reason has the capacity to perceive what is good for human beings by following the
"order of our national inclinations." These Aquinas lists as self-preservation (an end that human
beings share with all substances), family life and bringing up offspring (which is shared with all
animals), and the goals of knowing God and living in society (which are shared with all rational
creatures). These goals in turn are seen as obligatory because practical reason perceives as a
basic principle that "good is to be done and evil is to be avoided," which is a self-evident
principle like the principle of non-contradiction.
3rd Art. Are all acts of virtue prescribed by the law? Ans.: Yes, but only insofar as each person’s
reason naturally dictates to him to act virtuously. But if we consider the virtuous acts themselves,
i.e., in their proper species, then not all virtuous acts are prescribed by natural law, because many
things are done virtuously to which nature does not incline at first but which, through the inquiry
of reason, have been found by men to be conducive to living well.
4th Art. Is the natural law the same in everyone? Ans.: In terms of general principles, yes. But in
terms of the conclusions drawn from those principles, the truth is not the same for all in all cases.
Certain obstacles can prevent the concretization of the law in the best way, and our reason can
get perverted by passions or evil so that we don’t have full knowledge of the law.
5th Art. Can natural law be changed? Ans.: “First” principles cannot. But “secondary” precepts of
natural law, which “follow as immediate conclusions from first principles,” can be changed “in a
few cases because some special reasons make its precepts impossible to observe,” although,
except for the mention of polygamy in the Old Testament, there is no further discussion of the
difference between the two types of principles. It is also possible for there to be additions to the
natural law of “provisions that are useful to human life.” Also, we must use prudence and equity
in our legislating. The latter is what lets a ruler depart from the letter of the law when its strict
application would violate its spirit.
6th Art. The natural law cannot be blotted out, because it is written on our hearts. Not even sin
can remove it.
Question 95: Human Law
1st Art. Are human laws useful? Ans.: Yes, because they restrain—through fear of punishment—
those prone to vice, people who must be led to virtue through compulsion.
2nd Art. Do all human laws come from the natural law? Ans.: Yes, insofar as they are just. A law
is just if it is in accord with reason. The first rule of reason is the law of nature. Also, human
laws are conclusions based on principles, which come from the natural law.
3rd Art. Divine law fosters religion; natural law fosters discipline; and human law fosters the
common good.
Law of Nations: is related to natural law as "conclusions from principles," conclusions that
enable people to relate to one another in all societies.31 Aquinas therefore classifies the law of
nations as a type of human law, that is, the particular applications of natural law derived by
reason, while he calls the more specific and variable applications of human law "civil law" (from
civitas = 'city'). Both varieties of human law are derived from natural law, and if human law
disagrees with natural law, "it is no longer a law, but a corruption of law.”