ncipes sit_. Whence it
is clear, as St. Thomas says (2a 2ae, q. 40, art. I), [10] that a
private person cannot lawfully make war; for, if he is aggrieved,
he should resort to his superior for satisfaction; and it is as
little within the right of a private individual to collect such a
body of men as is requisite to carry on a war. The difficulty is to
understand what is meant by "public person" or "prince;" for it is
plain that it is not lawful for every prince or judge whatsoever to
wage war. The solution of this difficulty, according to St. Thomas
(_ubi supra_,) and Cajetanus (_ibi_ and in _Summa, ch. Bellum_),
and Castro (_De justa haereticorum punitione_ lib. 2, c. 4), is that
by "public person" in the present case is understood the one who in
his government depends not on another; such are the kings of Spain
and France, also some free commonwealths, as Venice, Florence, and
Ferrara: these have authority, without recourse to another, to wage
war. But those princes and states whose government is not sovereign
may not levy war without authority from their superior; and so the
lords of Castilla and the viceroys and governors appointed by our
king Philippus may not without a warrant make war.

What is said applies not when war is waged for defense against enemies,
but in other circumstances; for if it is for defense, such war is
permitted to any governor or king, as the authors say, because _vim
vi repellere licet_; [11] and thus the viceroys and governors of the
Indias have authority to levy war against disturbers of the peace and
quiet of the states of which they are in charge, without necessity
of resorting to his Majesty for permission.

The second condition of righteous war is that the cause for which it
is waged shall be a just one, as St. Thomas says: "Those upon whom
war is waged deserve it for the offenses that they have committed,
and the grievances that they have inflicted upon the one who makes
war on them." Thus says St. Augustine (lib. 83. _Quaestionum super
Josue_, 9. 10), and Gratian quotes him (23, q. 2, c. _Dominus noster_):
_Justa autem bella solent definiri quae ulciscuntur injurias, si gens
vel civitas plectenda est, quod vel vindicare neglexerit quod a suis
improbe factum est, vel reddere quod per injuriam ablatum est_. [12]
And as this injury and grievance may be of many kinds, so too, many
and various are the just causes of war; but we will consider here only
those which make for the matter in