St. Thomas Aquinas wrote a famous series of questions in the Summa Theologiae
on law and sometimes this is called his Treatise on Law.
It's often read by students of law and of political theory, but if you really want to
understand it, it's important to know that when Aquinas speaks about law, he's speaking
about much more than we usually think of.
Many people assume that law is a legislative or judicial domain, something that lawyers,
judges and politicians deal with.
And often we assume that law is primarily about commands, obligations or moral imperatives
controlling what other people are free to do.
But with Aquinas, law has quite a different sense.
Law is not about commandments and obligations primarily, but rather is about a rational
or reasonable principle of order by which things are directed to their ends.
And in this way, law is a teacher.
Aquinas also says that law is a rule and measure of human acts. So you might think of a ruler.
A ruler guides you in drawing a straight line and the straightness and length of the ruler
is also the measure of the line you've drawn.
In a similar way the law guides us in our actions to make sure they're upright and ordered
to the common good and it also gives us a way to judge our actions.
It measures them, whether we have conformed our actions to the standard of the law.
Aquinas offers a famous definition of law, "An ordination of reason for the common good
from him who has care of the community, which is promulgated or made known."
Two elements here are worth highlighting.
First law is an ordination of reason.
That means that law involves some kind of ordering and specifically an ordering according
to reason.
Now Aquinas's definition on this point is very different from those of other thinkers
who will say things like law is a command of the will of a superior.
For St. Thomas law is not like this.
It's not a commandment of the superior's will.
It's an expression of his reason consisting in a kind of reasoned plan or ordering of
things towards the common good, and this brings us to the second point.
Law is an ordering to the common good.
The common good is the end that law aims at and serves.
What is the common good?
Here, there's lots of confusion.
You might think for example, that the common good is like a pizza.
We all chip in and buy one and then we distribute the slices among us.
The problem with this is that while we might own a pizza in common, a slice of pizza cannot
be consumed by two of us at the same time.
If I eat this slice, no one else can eat it.
Of its very nature, pizza is a private good.
How is the common good different?
It's a good of a radically different kind because it is an end, and it can be shared
by many without loss or diminishment.
Think of common goods like the truth or justice in a city or victory for a sports team.
These are goods that can be shared by many.
They're not like slices of pizza.
They're higher and nobler goods.
They're ends that we aim at in our common activity.
So a school aims at the truth.
A city aims at justice, a sports team aims at winning.
These common goods can be shared without being diminished.
When our team wins, you share in the victory.
And so do I, and neither of us has less because it's shared.
Likewise on a sports team, a good team player won't insist on taking every shot.
He'll pass the ball and let another player score because his goal is that the team would
win, and when the team wins, it's a victory for him and also for all of the other players,
and even for the fans.
It's the same victory and players and fans alike rejoice in it.
It's the private property of none of them.
And yet it's genuinely good for each of them because it's a common good.
In a certain sense, the common good is the explanation of why a law exists
and what it's doing.
Law is an ordering based on reason for the sake of and directing the community towards
the common good.
And the common good is analogical, which means you can find it in many different registers,
a sports team, a family, a school, they all have a common good.
It can also be found in ever greater radiance and nobility, from the common good of a city
to that of the whole political society.
And finally in the right ordering of all things to God as the common good and final end of
all that is.
This brings us back to the big picture, where we can begin to see the connections between
the four main types of law that Aquinas identifies.
They are the eternal law, natural law, divine positive law, and human law.
Aquinas understands these as arranged in a hierarchy where the lower types of law participate
in and make more specific the higher types.
Aquinas starts with the highest possible level, God himself, who not only is the creator of
the universe but is also its end, the source of its order and who governs it by his providential
plan.
This plan of order emerges from God's divine reason as an idea in God's mind.
And like God himself, this plan is eternal and so St. Thomas calls this the eternal law.
Eternal law therefore does not mean a bunch of divine commandments or statutes.
Rather, Aquinas is referring to the whole plan of creation itself.
That God creates the whole cosmos and every being in it, in its right place and ordered
to its proper end or goal.
Ultimately that creation would reflect and share in the glory and splendor of God.
This brings us to the second kind of law, natural law, which we'll discuss in
more detail in another video.
Aquinas thinks that the eternal law is not only in God's mind, it's also in the things
that God makes.
Because God has created all things according to a plan as coming from him and ordered back
to him, he imprints on their very being, in their very natures, an inclination for creatures
towards their proper acts and ends.
So they will tend to their perfection and fulfillment precisely as the kinds of things
they are according to the natures God has given them.
The natural law means in particular the way that rational creatures like human beings
participate in God's plan, that is in the eternal law.
Unlike lower creatures, we human beings are not only moved to our end from
the outside, we use our reason, we use our minds to actively participate in directing
ourselves, ordering ourselves and ordering and directing others, including cities, nations,
our families and things like that towards their ultimate end.
And we do this insofar as we understand what kind of beings we are and what is really good
for us.
And so act accordingly.
The third kind of law is divine positive law.
Aquinas means by this what God has revealed through divine revelation in the Old and New
Testaments about how human beings should live in order to come to the supernatural good
of heaven.
These are things that we could never have discovered on our own since knowing and traveling
on the way to perfect communion with the triune God completely exceeds what our nature is
capable of by its own power.
The fourth kind of law is human law, which we'll also talk about in another
video.
Human law exists in various levels as we know very well from our own experience.
So, for example, the law of a nation or of a state or of a city, and this kind of law
is also an ordination of reason for the common good.
In this case, the common good of the nation, of the state, of the city.
Human law is also more particular and specific than the natural law.
It doesn't apply everywhere like the natural law does, but only in this jurisdiction, and
it aims to direct this particular community and its members to their proper common good.
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