But while northern nations were conspicuous for the substantial and ponderous nature of their oaths, the Roman yielded to none in the multiform versatility of his adjurations. Caligula owned a horse that he not only treated as a fellow-being and brought to meals at his table, but whose name served him wherewith to pronounce his accustomed oaths. The same emperor is reported to have put to death a Roman citizen who refused to swear by his "imperial genius." Another of the oaths prescribed by command of Caligula was "per numen Drusillæ." This wretched woman he constrained his subjects to worship as a divinity. To explain this partiality for the use of these absurd if not impious oaths, it would seem that a tradition had been circulated, ascribing the duration of his own lifetime to the period during which the oath should pass current. Any attack of illness that happened to the emperor was directly attributed to the waning popularity of the oath. Nor was the doctrine strange to many of the nationalities over which the Roman sway extended. We have it distinctly occurring among the Scythians,[21] and it has more recently been noticed by travellers as existing among half-barbarous tribes. The oath itself was probably a development of the affirmation that has been used more than any other in the history of the world. The _life_ or the _head_ of the ruler of the chief tribesman, or of the spiritual prophet, has invariably furnished the true standard of affirmation. But even as a mere domestic oath, the _head_ of the goodman of the house seems to have been permitted a degree of solemnity--
"Per caput hoc juro, per quod pater ante solebat." _Virgil_, Æn. ix. 300.
"He swore by the wound in Jesu's side."--_Coleridge, 'Christabel.'_
We may now turn our backs upon the luxuriant and fanciful swearing of the ancient world and pursue our researches into one other division of the subject that gives rise to more serious reflections. The diversions of the Roman and the Greek in the way of imprecation seem to have been mostly intended in good part, and to have been productive of little theological odium. But there is a body of swearing that has diffused itself through Christian countries which is the very reverse of sportive, and has undeniably provoked the strongest feelings of aversion. The abuse to which we allude consisted mainly in the indiscriminate use of popular oaths that selected the limbs and members of Christ as the paraphernalia of swearing. There does not appear at the present day any great irreverence in the exclamation, "S'light," or "S'lid," or "Bodikins," as, happily, the wave of impiety that brought them has long since broken and passed away. Indeed, as they now occur in the pages of sixteenth century writings, they only strike the modern reader in the light of so many interruptions from the text. But we shall find as we pursue the inquiry further, that there was a great deal of meaning wrapped up in these expletives, and that they played a by no means unimportant part in the workings of the mediæval understanding.