Augustine and Aquinas 153If violence within a state is vigorously condemned, what then
does Aquinas think about international violence, i.e., war? The
natural law allows individuals to use force to protect themselves
as the right of self-defense. States also have this right. Aquinas
set down what he calls the conditions for a just war. First of all,
a war must be fought for a just cause, for example, when one
nation is invaded by an another. The war must be fought by a
legitimate authority; self-appointed groups of terrorists, or spe
cial interest groups have no legitimate authority to engage in
war. Also, it must be reasonably determined that the resulting
evil that will come from fighting the war will be less than the evil
that would result from not fighting. In this regard, a war should
be brought to a conclusion as quickly as possible.
Obviously, it is easy, according to Aquinas’ criteria, to judge
some wars as just or unjust. Some wars, however, seem just at the
start, but as time passes, become unjust. Some wars, just in most
respects, result in injustice by virtue of their length or the
excesses of the participants. Reason and an objective regard for
the facts are crucial to the making of the judgment. The terrorist
does not become a freedom fighter simply because we agree with
his ideology, nor does a freedom fighter become a terrorist
because we disagree with his objectives. Clearly, in most cases
the reasonable application of the criteria can aid in making the
judgment.
Aquinas’ concern for the importance of law is evidenced by
his careful and complete treatment of the four types of law.
Eternal law is the law of the universe, the physical laws which
reflect the divine order, pattern, and rationality of the universe.
Natural law is the tendency of living things, as Aristotle said, “to
fulfill the essence of their beings.” In man, this is to live as a
rational being. Divine law is the law revealed by God through his
commandments and scripture and most importantly through
Christ. Human law is “an ordinance of reason for the common
good made by him who has care of the community, and promul
gated.” In a very real sense, human law is a corollary to the
natural law. The natural law, discerned through reason, tells us
that murder is wrong. Human law is meant to define, prescribe
penalties for, and otherwise distinguish murder from other forms
of homicide.
Human law, then, should be consistent with natural law in all