On the other hand, when reason is not opposed, even a war which in itself involves an injury is not unjust from the standpoint of subjects.b This principle (as Victoriac maintains in his refutation of Adrian’s opinion) is applicable even in the case of subjects who are doubtful as to the justice [of a war]. For we have laid down a ruled to the effect that “The authorities must be obeyed”; and no one may depart therefrome save through an application of the Thirteenth Law, whereas a person in doubt makes no such application. Neither is any obstacle presented by the precept, “Commit no act concerning which you are doubtful”; for he who is in doubt as to the justice or injustice of a war proclaimed by command, does not forthwith conceive an additional doubt as to whether or not obedience is due in doubtful cases. Moreover, while the foregoing argument is valid even in cases where reason fails in the sense that no definite decision is reached, the same argument will have far greater force when the reason of the subject favours the war, as it does quite properly in a great many instances.
New explanation
For right is based upon fact. And facts—that is to say, specific facts—are learned neither through art nor through science, which are of a purely universal nature. Again, very few facts are discernible through the senses, since we cannot be in more than one place at one particular time, and since the senses perceive only those things which are very close at hand. Yet there is no other way of attaining to true knowledge. Impelled thus by necessity, human reason has fashioned for itself certain rules of probability, or τω̑ν εἰκότων, for passing judgement in regard to facts. These rules consist of various προλήψεις, or (to use the Latin term) praesumtiones [preliminary assumptions], which are not fixed and unchangeable like scientific rules but rather of a character considered concordant in the greatest possible degree with nature; that is to say, on the basis of what commonly occurs, conclusions of a similar trend may be drawn.a In this sense, a question of fact may be called conjectural. For, among the proofs which we accept in forming judgements, there is not one that is necessarily conclusive; on the contrary, all of them are derived from the aforesaid preliminary assumptions ὡς ἐπὶ τὸ πολύ, “based on what commonly occurs.”b [34]
Now, the primary principle among these assumptions of fact would seem to be our supposition that those inclinations which are in the highest degree natural (such as the inclinations toward the True and toward the Good), as well as the others derived therefrom, exist inherently in some measure within all things. Here we have the source of such concepts as assured belief in posterity, the beneficial nature of property ownership, the credibility of witnesses or documents, and the gravity of oaths. Moreover, not only does the rule of charity instruct us to think well of private individuals,c but also (and this is a particularly important point) both reason and Holy Writd forbid disparagement of magistrates. For magistrates have the support of the weightiest preliminary assumptions, partly because of the oath they customarily take, partly as a result of the general consent expressed by the state and the testimonial of confidence given by the citizens, considerations of such a nature that anyone holding a different opinion in regard to these officials would not only be charging the magistrates themselves with treachery but would also condemn a vast multitude of persons on a charge of folly. For all such charges would be contrary to those natural impulses which I have called “inclinations.” Furthermore, if anyone who practises a particular profession or art is properly regarded as expert and painstaking in his special field,a why, pray, should not magistrates be considered to have judged wisely (inasmuch as they are the Priests of Justice) concerning the cause of a war? For it is the function of a good magistrate to formulate such judgements. And when the magistrates hold that things justifying entry into war have befallen the citizens, why should not faith be placed in those authorities, as in persons who speak the truth?b Yet again, why should it not be right to believe that the laws of an inferior order are in agreement with the higher laws, and that the commands of the magistrate are identical with the commands of God,c whenever no obstacle exists to preclude such a belief? In short, subjects subordinate to a given state or magistrate occupy a position analogous to that occupied by children and slaves, who are subject respectively to the solemn patria potestas and to the power of the master.
Nevertheless, when we append the condition that reason must not rebel, it should be understood that we are referring to reason guided by the weighing of probabilities. For neither crass ignorance (for example, ignorance of the natural law) nor lack of knowledge regarding a fact which anyone ought to have known, constitutes an excuse for sinning.d There are certain things, indeed, of which one cannot be blamelessly ignorant; and, according to the teachings of both the jurists and the philosophers,e this very condition of blameworthy ignorance merits punishment.
But we have demonstrated the validity of the opinion which tends not a little to placate the consciences of many persons. Augustinea has expounded this opinion in the following terms: “Therefore, the just man, if he should by chance be serving as a soldier even under an impious king, may righteously wage war at the latter’s command, provided that, while he observes the dispositions of rank established to maintain peace within the state,7 it is certain either that the order issued to him is [34′] not contrary to the law of God, or, at least, uncertain that the order does conflict with God’s law; so that the king may perhaps be held responsible for an unjust command while the soldier is shown to be innocent because of his rank as one who serves.”
Conclusion VI, Article III
We ourselves shall state our conclusion thus: For subjects, that war has a just cause which is ordered by a superior, provided that the reason of the subjects is not opposed thereto after weighing the probabilities.b
Through this same process of reasoning, we arrive at the answer to another question, namely: what persons may justly be attacked in war by subjects? In the [Civil] Law,c the enemies of the Romans are defined as those against whom the Roman People have decreed war. Indeed, in all parts of the world, subjects justly wage war upon those against whom war is ordained by the state or magistrate of the said subjects, save in cases conflicting with the limitation explained abovea