(a) All schismatics incur _ipso facto_ excommunication, as well as various inhabilities and penalties (Canon 2314). It is fitting that those who separate themselves should be declared outside the communion of the faithful, and this is what Moses commanded to be done at the time of the schism of Core: “Depart from the tent of these wicked men and touch nothing of theirs, lest you be involved in their sin” (Num., xvi. 26).
(b) The excommunicated are forbidden the celebration of Mass and the active use and administration of the Sacraments and sacramentals, except when the faithful apply to them or when there is danger of death, as declared in Canon 2261.
(c) The excommunicated are denied the power of jurisdiction except in certain cases where the Church grants it for the sake of the common good. Thus, they may give absolution in danger of death (Canon 882), or in common error (Canon 209), or at request, if they are not _vitandi_ or sentenced (Canon 2261). It is the teaching of learned authorities that the Roman Church for the good of souls has allowed ecclesiastical jurisdiction to remain in the schismatic Oriental Churches for the conferring of the Sacraments.
1376. War.—War is defined as a state of conflict between two or more sovereign nations carried on by force of arms.
(a) It is a state of conflict, and so differs from passing conflicts, such as battles, skirmishes, campaigns. The enemy in war is not only those with whom one is actually fighting, but all those who side with them, as counsellors, helpers, etc.
(b) War is between sovereign nations, and so differs from civil war, sedition, riots, duels. Moreover, war is made by nation against nation, not against particular individuals or groups of individuals within a nation.
(c) It is carried on by force of arms, and so differs from trade war, rivalry in preparedness for war, embargo, blockade, breach of diplomatic relations, etc.
1377. There are two kinds of war, just and unjust. (a) War is just when undertaken for a right cause (e.g., the independence of the nation); (b) it is unjust when undertaken for a wrong cause (e.g., the enslavement of a nation).
1378. Just war is either offensive or defensive. (a) Offensive war is attack made on an enemy in order to avenge an injury or enforce a right (e.g., invasion of the enemy’s territory to obtain compensation for damages inflicted by him); (b) defensive war is resistance to unjust attack made or menaced by an enemy (e.g., war made on the invader of one’s country).
1379. Just war is called defensive in two senses. (a) In the strict sense, it is defensive when the nation whose rights are unjustly attacked does not initiate hostilities, that is, does not declare or begin the war. (b) In a less strict sense, it is defensive when the nation unjustly attacked declares war or strikes the first blow. Thus, if the innocent nation knew that the enemy was secretly preparing war against its independence, it would be on the defensive, even though it declared war.