70 Law and Morality Abroad (to ca. ad 1550)Th ere were several important specifi c diff erences between just wars and
self- defense. One was that the just-war principle of auctoritas did not apply,
so that self- defense was available to ordinary subjects on their own initia-
tive. In fact, self- defense could even be exercised against a superior. Th e prin-
ciple of personae also did not apply to self- defense, so that even clergy were
entit led to defend t hemselves when assau lted. Fina lly, t he right of self- defense
in the narrow sense was confi ned to warding off the attack. It did not autho-
rize punitive action against the attacker, as was possible in a just war.
Just- war doctrine must be seen as conservative in character, in the spe-
cifi c sense that it was designed for the vindication of existing rights. Th ere
was no conception that a just war could ever be a means for the creation of
new rights that had not existed before. A just war was therefore, in essence,
what could be called a war of execution, meaning a war to enforce the law. It
could also be thought of as a police action. It was waged, ultimately, on be-
half of the rule of law as such, and not merely in the parochial interest of the
party waging it.
Th e just- war schema did not have explicit rules about peacemaking, but
the principles of res and animus placed some powerful constraints, if only
by implication, onto the just side. If the just side was fortunate enough to
triumph, then it was entitled to recover the res over which the war was fought.
But the just victor must go no further than that. He is only entitled to gain (or
recover) possession of that which was already his, in the eyes of the law, even
before the war began.
About the actual conduct of wars once they were under way, just-war doc-
trine had nothing explicit to say. Nevertheless, certain very broad principles
concerning the conduct of war did emerge as logical consequences of the
fi vefold schema. For example, the element of res placed a limit, at least im-
plicitly, on the duration of the confl ict (by requiring the fi ghting to stop once
the res had been attained). It also implied a limit on the quantity of enemy
property that could be captured: the just side was entitled to take only so
much as was necessary to satisfy its original claim, and no more. More sig-
nifi cant was the element of animus. Any fi ghter who possessed the correct
animus would refrain from committing any gratuitous or unnecessary vio-
lence against the enemy side, since the enemy soldiers were not, per se, the
real target. Th is implicit ban on the commission of gratuitous or unneces-
sary violence remains a fundamental principle of the laws of war to this day.