XVII. (82) Having now spoken of the second commandment to the best of our ability, let us proceed to investigate the one which follows with accuracy, as is pointed out by the order in which they come. The next commandment is, “not to take the name of God in vain.” Now the principle on which this order or arrangement proceeds is very plain to those who are gifted with acute mental vision; for the name is always subsequent in order to the subject of which it is the name; being like the shadow which follows the body. (83) Having, therefore, previously spoken of the existence of God, and also of the honour to be paid to the everlasting God; he then, following the natural order of connection proceeds to command what is becoming in respect of his name; for the errors of men with respect to this point are manifold and various, and assume many different characters. (84) That being which is the most beautiful, and the most beneficial to human life, and suitable to rational nature, swears not itself, because truth on every point is so innate within him that his bare word is accounted an oath. Next to not swearing at all, the second best thing is to keep one’s oath; for by the mere fact of swearing at all, the swearer shows that there is some suspicion of his not being trustworthy. (85) Let a man, therefore, be dilatory, and slow if there is any chance that by delay he may be able to avoid the necessity of taking an oath at all; but if necessity compels him to swear, then he must consider with no superficial attention, every one of the subjects, or parts of the subject, before him; for it is not a matter of slight importance, though from its frequency it is not regarded as it ought to be. (86) For an oath is the calling of God to give his testimony concerning the matters which are in doubt; and it is a most impious thing to invoke God to be witness to a lie. Come now, if you please, and with your reason look into the mind of the man who is about to swear to a falsehood; and you will see that it is not tranquil, but full of disorder and confusion, accusing itself, and enduring all kinds of insolence and evil speaking; (87) for the conscience which dwells in, and never leaves the soul of each individual, not being accustomed to admit into itself any wicked thing, preserves its own nature always such as to hate evil, and to love virtue, being itself at the same time an accuser and a judge; being roused as an accuser it blames, impeaches, and is hostile; and again as a judge it teaches, admonishes, and recommends the accused to change his ways, and if he be able to persuade him, he is with joy reconciled to him, but if he be not able to do so, then he wages an endless and implacable war against him, never quitting him neither by day, nor by night, but pricking him, and inflicting incurable wounds on him, until he destroys his miserable and accursed life.