One of the leading thoughts in the letter has been warning against sins of the tongue (i. 19, 26; iii. 1-12; iv. 11, 13; v. 9). He has spoken against talkativeness, unrestrained speaking, love of correcting others, railing, cursing, boasting, murmuring. One grievous form of sinful speech he has not mentioned particularly; and about this he adds a strong word of warning in this postscript to the Epistle: "Above all things, my brethren, swear not."
Two questions are raised by this remarkable prohibition—first, the exact meaning of it, especially whether it forbids swearing for any purpose whatever; and secondly, its relation to the almost identical prohibition uttered by Christ in the Sermon on the Mount (Matt. v. 35, 36). It will be obvious that whatever this relation may be, the meaning of our Lord's injunction determines the meaning of St. James in his injunction. It is hardly worth arguing that he did not mean either more or less than Christ meant.
I. The immediate context of the prohibition is worth noting in each case; it seems to throw light upon the scope of the prohibition. Jesus Christ, after saying "Swear not at all; neither by the heaven, ... nor by the earth.... But let your speech be, Yea, yea; Nay, nay," goes on to forbid retaliation of injuries, and to enjoin love towards enemies. St. James enjoins long-suffering towards enemies, thence goes on to forbid swearing, and then again returns to the subject of how to behave under affliction and ill-treatment: "Is any among you suffering? let him pray." Prayer, not cursing and swearing, is the right method of finding relief. There is, therefore, some reason for thinking that both in the Sermon on the Mount and here the prohibition of swearing has special reference to giving vent to one's feelings in oaths when one is exasperated by injury or adversity. No kind of oath is allowable for any such purpose.
But it is quite clear that this is not the whole meaning of the injunction in either place. "But let your speech be, Yea, yea; Nay, nay;" and, "But let your yea be yea, and your nay, nay," manifestly refers to strengthening affirmations and negations by adding to them the sanction of an oath. There was an old saying, now unhappily quite grotesque in its incongruity with facts, that "an Englishman's word is as good as his bond." What Christ and St. James say is that a Christian's word should be as good as his oath. There ought to be no need of oaths. Anything over and above simple affirming or denying "cometh of the evil one." It is because Satan, the father of lies, has introduced falsehood into the world that oaths have come into use. Among Christians there should be no untruthfulness, and therefore no oaths. The use of oaths is an index of the presence of evil; it is a symptom of the prevalence of falsehood.
But the use of oaths is not only a sign of the existence of mischief, it is also apt to be productive of mischief. It is apt to produce a belief that there are two kinds of truth, one of which it is a serious thing to violate, viz. when you are on your oath; but the other of which it is a harmless, or at least a venial thing to violate, viz. when falsehood is only falsehood, and not perjury. And this, both among Jews and among Christians, produces the further mischievous refinement that some oaths are more binding than others, and that only when the most stringent form of oath is employed is there any real obligation to speak the truth. How disastrous all such distinctions are to the interests of truth, abundant experience has testified: for a common result is this;—that people believe that they are free to lie as much as they please, so long as the lie is not supported by the particular kind of oath which they consider to be binding.
Thus much, then, is evident, that both our Lord and St. James forbid the use of oaths (1) as an expression of feeling, (2) as a confirmation of ordinary statements; for the prohibitions plainly mean as much as this, and we know from other sources that these two abuses were disastrously common among both Jews and Gentiles at that time. That converts to Christianity were exempt from such vices is most improbable; and hence the need that St. James should write as he does on the subject.
But the main question is whether the prohibition is absolute; whether our Lord and St. James forbid the use of oaths for any purpose whatever; and it must be admitted that the first impression which we derive from their words is that they do. This view is upheld by not a few Christians as the right interpretation of both passages. Christ says, "Swear not at all (μὴ ὀμόσαι ὅλως).... But let your speech be, Yea, yea; Nay, nay." St. James says, "Swear not, neither by the heaven, nor by the earth, nor by any other oath (μήτε ἄλλον τινὰ ὅρκον): but let your yea be yea, and your nay, nay." In both cases we have an unqualified prohibition of what is to be avoided, followed by a plain command as to what is to be done.
But further investigation does not confirm the view which is derived from a first impression as to the meaning of the words. Against it we have, first, the fact that the Mosaic Law not only allowed, but enjoined the taking of an oath in certain circumstances; and Christ would hardly have abrogated the law, and St. James would hardly have contradicted it, without giving some explanation of so unusual a course; secondly, the indisputable practice of the early Church, of St. Paul, and of our Lord Himself.
In Deuteronomy we read, "Thou shalt fear the Lord thy God; and Him shalt thou serve, and shalt swear by His Name" (vi. 13); and, "to Him shalt thou cleave, and by His Name shalt thou swear" (x. 20). The Psalmist says, "The king shall rejoice in God; every one that sweareth by Him shall glory: but the mouth of them that speak lies shall be stopped" (lxiii. 11). Isaiah says, "He that sweareth in the earth shall swear by the God of truth" (lxv. 16); and still more strongly Jeremiah: "Thou shalt swear, As the Lord liveth, in truth, in judgment, and in righteousness" (iv. 2); and, "If they will diligently learn the ways of My people, to swear by My Name, As the Lord liveth; even as they taught My people to swear by Baal; then shall they be built up in the midst of My people" (xii. 16. Comp. xxiii. 7, 8). An absolute prohibition of all swearing would have been so surprisingly at variance with these passages of Scripture that it is difficult to believe that it would have been made without any allusion to them. Even the Essenes, who were very strict about swearing, and considered it to be worse than perjury (for a man is condemned already who cannot be believed except upon his oath), imposed "terrific oaths" (ὅρκους φρικώδεις) upon those who wished to enter their community, before admitting them (Josephus, Bell. Jud. II. viii. 6, 7; Ant. XV. x. 4); and we can hardly suppose that St. James means to take up a more extreme position than that of the Essenes.
But even if we suppose that he does mean this we have still to explain the practice of those who were well aware of Christ's command respecting swearing, and certainly had no intention of deliberately violating it. If the first Christians were willing on certain occasions to take certain oaths, it must have been because they were fully persuaded that Jesus Christ had not forbidden them to do so. When called upon by heathen magistrates to take an oath, the distinction which they drew was not between swearing and not swearing, but between taking oaths that committed them to idolatry and oaths which did nothing of the kind. The latter oaths they were willing to take. Thus Tertullian says that they would not swear by the genii of the emperors, because these were supposed to be demons; but by the safety of the emperors they were willing to swear (Apol. xxxii.). Origen writes to much the same effect (Con. Celsum, viii., lxv.). The oath by the genius, or numen, or "fortune" (τύχη) of the emperor was recognized as a formula for abjuring Christianity. Thus the proconsul presses Polycarp again and again: "Swear by the genius of Cæsar; swear the oath, and I will release thee" (Mart. Pol. ix., x.); and the fear of being betrayed into an act of idolatry was one of the main reasons why the early Christians disliked taking oaths. But there was also the feeling that for Christians oaths ought to be quite unnecessary. Thus Clement of Alexandria says that the true Christian ought to maintain a life calculated to inspire such confidence in those without that an oath would not even be demanded of him. And of course, when he swears, he swears truly; but he is not apt to swear, and rarely has recourse to an oath. And his speaking the truth on oath arises from his harmony with the truth (Strom. vii., viii.). Pelagius maintained that all swearing was forbidden; but Augustine contends, on the authority of Scripture, that oaths are not unlawful, although he would have them avoided as much as possible (Ep. clvii. Comp. Epp. cxxv., cxxvi.).