142. When Constantine was on his march to Rome to attack Maxentius, at a time when he was as yet undecided about the truth of Christianity, a luminous Cross is said to have appeared in the sky at mid-day, in sight of himself and his army, with the inscription, “In this conquer.” 1 His victory and his conversion followed. The date of these transactions is A.D. 311 and 312.
143. Now, here the fact reported is plainly miraculous. No known physical cause could have formed a sentence of Greek or Latin in the air. It has sometimes been supposed, indeed, that letters were not really exhibited, but only some emblem, such as a crown, which denoted conquest 2; and that then what remains of the phenomenon may be resolved into meteoric effects. But since any extraordinary appearance at such a juncture, whatever be its physical cause, or whether it have one or no, is undeniably the result of an immediate Divine superintendence, it is not easy to see what is gained by an hypothesis of this nature. If in matter of fact our Lord was then really addressing Constantine, it seems trifling to make it a grave point to prove that He did so in this way, and not in that. In such a case nature either would be made to minister, or would be no impediment, to His Will; and His Will to address Constantine is sufficient surely by itself to account for a contravention or suspension of the laws of nature, and to overcome the presumption which primâ facie lies against the miracle. That He should address Constantine intelligibly is a miracle already. And surely to sway and overrule the physical system towards a moral object, is a miracle only different in degree from an interference with it for such an object. For this is to impose on nature a constraint beyond and above itself, i.e. a supernatural constraint; and if it is subordinate to moral laws, why should it not sometimes give way to them? In short, does the case ever stand thus, if it may be reverently said that the Almighty would address man, unless nature stood in the way? Does He fetter Himself with its laws, who, even in the days of His flesh, did but submit to them, in order in the event to dispense with them? Such explanations, then, either imply that the inviolability of creation is more sacred than a Purpose of the Creator, or they tamper with historical evidence for an insufficient end. To mutilate the evidence is to incur all the difficulty of denying it, with none of the gain. So this question may be passed over.
144. In the next place the à priori aspect of the reported miracle, if it is so to be called 3, is in its favour. The approaching conversion of the Roman empire, in the person of its head, was as great an event as any in Christian history. Constantine’s submission of his power to the Church has been a pattern for all Christian monarchs since, and the commencement of her state establishment to this day; and, on the other hand, the fortunes of the Roman empire are in prophecy apparently connected with her in a very intimate manner, which we are not yet able fully to comprehend. If any event might be said to call for a miracle, it was this; whether to signalize it or to bring it about. Thus it was that the fate of Babylon was written on the wall of the banqueting hall; also portents in the sky preceded the final destruction of Jerusalem, and are predicted in Scripture as forerunners of the last day. Moreover our Lord’s prophecy of “the Sign of the Son of Man in heaven” 4 was anciently understood of the Cross. And, further, the sign of the cross was at the time, and had been from the beginning, a received symbol and instrument of Christian devotion, and cannot be ascribed to a then rising superstition. Tertullian speaks of it as an ordinary rite for sanctifying all the ordinary events of the day; it was used in exorcisms; and, what is still more to the point, it is regarded by St. Justin, Tertullian, and Minucius as impressed with a providential meaning upon natural forms and human works, as well as introduced by divine authority into the types of the Old Testament.
One would be inclined then to receive the wonderful event in question on very slight evidence, if that evidence were good as far as it went; and now let us see what, and of what kind, is producible in its behalf. It is on the whole sufficient, yet not without its difficulties.