Part 3
38 The Unity of God shown by the Harmony of the order of Nature.
Since then, there is everywhere not disorder but order, proportion and not disproportion, not disarray but arrangement, and that in an order perfectly harmonious, we needs must infer and be led to perceive the Master that put together and compacted all things, and produced harmony in them. For though He be not seen with the eyes, yet from the order and harmony of things contrary it is possible to perceive their Ruler, Arranger, and King. 2. For in like manner as if we saw a city, consisting of many and diverse people, great and small, rich and poor, old and young, male and female, in an orderly condition, and its inhabitants, while different from one another, yet at unity among themselves, and not the rich set against the poor, the great against the small, nor the young against the old, but all at peace in the enjoyment of equal rights,— if we saw this, the inference surely follows that the presence of a ruler enforces concord, even if we do not see him; (for disorder is a sign of absence of rule, while order shows the governing authority: for when we see the mutual harmony of the members in the body, that the eye does not strive with the hearing, nor is the hand at variance with the foot, but that each accomplishes its service without variance, we perceive from this that certainly there is a soul in the body that governs these members, though we see it not); so in the order and harmony of the Universe, we needs must perceive God the governor of it all, and that He is one and not many. 3. So then this order of its arrangement, and the concordant harmony of all things, shows that the Word, its Ruler and Governor, is not many, but One. For if there were more than one Ruler of Creation, such an universal order would not be maintained, but all things would fall into confusion because of their plurality, each one biasing the whole to his own will, and striving with the other. For just as we said that polytheism was atheism, so it follows that the rule of more than one is the rule of none. For each one would cancel the rule of the other, and none would appear ruler, but there would be anarchy everywhere. But where no ruler is, there disorder follows of course. 4. And conversely, the single order and concord of the many and diverse shows that the ruler too is one. For just as though one were to hear from a distance a lyre, composed of many diverse strings, and marvel at the concord of its symphony, in that its sound is composed neither of low notes exclusively, nor high nor intermediate only, but all combine their sounds in equal balance—and would not fail to perceive from this that the lyre was not playing itself, nor even being struck by more persons than one, but that there was one musician, even if he did not see him, who by his skill combined the sound of each string into the tuneful symphony; so, the order of the whole universe being perfectly harmonious, and there being no strife of the higher against the lower or the lower against the higher, and all things making up one order, it is consistent to think that the Ruler and King of all Creation is one and not many, Who by His own light illumines and gives movement to all.
39. Impossibility of a plurality of Gods.
For we must not think there is more than one ruler and maker of Creation: but it belongs to correct and true religion to believe that its Artificer is one, while Creation herself clearly points to this. For the fact that there is one Universe only and not more is a conclusive proof that its Maker is one. For if there were a plurality of gods, there would necessarily be also more universes than one. For neither were it reasonable for more than one God to make a single universe, nor for the one universe to be made by more than one, because of the absurdities which would result from this. 2. Firstly, if the one universe were made by a plurality of gods, that would mean weakness on the part of those who made it, because many contributed to a single result; which would be a strong proof of the imperfect creative skill of each. For if one were sufficient, the many would not supplement each other's deficiency. But to say that there is any deficiency in God is not only impious, but even beyond all sacrilege. For even among men one would not call a workman perfect if he were unable to finish his work, a single piece, by himself and without the aid of several others. 3. But if, although each one was able to accomplish the whole, yet all worked at it in order to claim a share in the result, we have the laughable conclusion that each worked for reputation, lest he should be suspected of inability. But, once more, it is most grotesque to ascribe vainglory to gods. 4. Again, if each one were sufficient for the creation of the whole, what need of more than one, one being self-sufficient for the universe? Moreover it would be evidently impious and grotesque, to make the thing created one, while the creators were many and different, it being a maxim of science that what is one and complete is higher than things that are diverse. 5. And this you must know, that if the universe had been made by a plurality of gods, its movements would be diverse and inconsistent. For having regard to each one of its makers, its movements would be correspondingly different. But such difference again, as was said before, would involve disarray and general disorder; for not even a ship will sail aright if she be steered by many, unless one pilot hold the tiller, nor will a lyre struck by many produce a tuneful sound, unless there be one artist who strikes it. 6. Creation, then, being one, and the Universe one, and its order one, we must perceive that its King and Artificer also is one. For this is why the Artificer Himself made the whole universe one, lest by the coexistence of more than one a plurality of makers should be supposed; but that as the work is one, its Maker also may be believed to be One. Nor does it follow from the unity of the Maker that the Universe must be one, for God might have made others as well. But because the Universe that has been made is one, it is necessary to believe that its Maker also is one.
40. The rationality and order of the Universe proves that it is the work of the Reason or Word of God.
Source: Against the Heathen (New Advent)