hand, confirmed by the authority
of Scripture.

The first ground of a righteous war may exist when one is hindered
from doing what he may by right do. This is matter of natural and
divine law and on this ground Julius Caesar, as Lucan represents him
(lib. 1), made defense of his conduct in waging war against the Roman
state--viz., that the state had blocked to him, a Roman citizen,
the route to Rome; and so he said, arms in hand, _Omnia dat qui justa
negat_. [13] On this ground, as St. Augustine says (in _Quaest. Num._
q. 43), [14] the children of Israel justly made war on the kings of
the Amorites (_Ut legitimum_, c. 21), for having withstood their
passage through their country when they were on their way to the
promised land, although the Israelites had given assurance that they
would do no damage to the lands, the crops, or the vineyards of the
Amorites. And so says St. Augustine (and he is quoted _ubi supra_,
last chapter), _Notandum est sane quemadmodum justa bella gerebantur
a filiis Israel contra Amoritas: innoxius enim transitus denegabatur
qui jure humanae societatis aequissimo patere debebat_. [15] Upon
which passage Joannes Andreas in his gloss well says: _Licet enim
transire per alienum agrum jus non sit, tamen quia necessarius et
innoxius erat iste transitus illi prohibere non debuerunt; item quia
via publica erat et nemo prohibetur via publica_. [16]

The second ground, as I said, of a righteous war is the self-defense
of the prince or of his subjects. This ground also is matter of both
natural and divine right; for even as self-defense is a natural
right, on which right is founded the rule of _vim vi repellere_,
so too in the prince is the defense of his subjects--for the care
which the prince has of his subjects is as essential on his part as
is the care which each one of them has for himself; hence, if the
subjects are aggrieved by their enemies, the prince may justly in
their defense make war, and _vim vi repellere_. This is much better
than that the individual should himself avenge the wrong; for the
individual can lawfully defend himself and his property only _in
continente_, as Sylvester declares (_Bellum_, 2 Sec. 3), but he may not
avenge past wrongs, _nec sua repetere_ save by recourse to his judge
and superior. [17] Whatever goes beyond that is contrary to law and
good government and, as Cajetan says, is _extra moderamen tutelae_,
[18] it being an essential condition of the right _vim vi repel