XIII. What now remains of their invincible arguments? Perhaps the last they will take refuge in is this. If God has never ceased to beget, the Generation is imperfect; and when will He cease? But if He has ceased, then He must have begun. Thus again these carnal minds bring forward carnal arguments. Whether He is eternally begotten or not, I do not yet say, until I have looked into the statement, “Before all the hills He begets Me,” more accurately. But I cannot see the necessity of their conclusion. For if, as they say, everything that is to come to an end had also a beginning, then surely that which has no end had no beginning. What then will they decide concerning the soul, or the Angelic nature? If it had a beginning, it will also have an end; and if it has no end, it is evident that according to them it had no beginning. But the truth is that it had a beginning, and will never have an end. Their assertion, then, that which will have an end had also a beginning, is untrue. Our position, however, is, that as in the case of a horse, or an ox, or a man, the same definition applies to all the individuals of the same species, and whatever shares the definition has also a right to the Name; so in the very same way there is One Essence of God, and One Nature, and One Name; although in accordance with a distinction in our thoughts we use distinct Names and that whatever is properly called by this Name really is God; and what He is in Nature, That He is truly called— if at least we are to hold that Truth is a matter not of names but of realities. But our opponents, as if they were afraid of leaving any stone unturned to subvert the Truth, acknowledge indeed that the Son is God when they are compelled to do so by arguments and evidences; but they only mean that He is God in an ambiguous sense, and that He only shares the Name.
XIV. And when we advance this objection against them, “What do you mean to say then? That the Son is not properly God, just as a picture of an animal is not properly an animal? And if not properly God, in what sense is He God at all?” They reply, Why should not these terms be ambiguous, and in both cases be used in a proper sense? And they will give us such instances as the land-dog and the dogfish; where the word Dog is ambiguous, and yet in both cases is properly used, for there is such a species among the ambiguously named, or any other case in which the same appellative is used for two things of different nature. But, my good friend, in this case, when you include two natures under the same name, you do not assert that either is better than the other, or that the one is prior and the other posterior, or that one is in a greater degree and the other in a lesser that which is predicated of them both, for there is no connecting link which forces this necessity upon them. One is not a dog more than the other, and one less so; either the dogfish more than the land-dog, or the land-dog than the dogfish. Why should they be, or on what principle? But the community of name is here between things of equal value, though of different nature. But in the case of which we are speaking, you couple the Name of God with adorable Majesty, and make It surpass every essence and nature (an attribute of God alone), and then you ascribe this Name to the Father, while you deprive the Son of it, and make Him subject to the Father, and give Him only a secondary honour and worship; and even if in words you bestow on Him one which is Equal, yet in practice you cut off His Deity, and pass malignantly from a use of the same Name implying an exact equality, to one which connects things which are not equal. And so the pictured and the living man are in your mouth an apter illustration of the relations of Deity than the dogs which I instanced. Or else you must concede to both an equal dignity of nature as well as a common name— even though you introduced these natures into your argument as different; and thus you destroy the analogy of your dogs, which you invented as an instance of inequality. For what is the force of your instance of ambiguity, if those whom you distinguish are not equal in honour? For it was not to prove an equality but an inequality that you took refuge in your dogs. How could anybody be more clearly convicted of fighting both against his own arguments, and against the Deity?
XV. And if, when we admit that in respect of being the Cause the Father is greater than the Son, they should assume the premiss that He is the Cause by Nature, and then deduce the conclusion that He is greater by Nature also, it is difficult to say whether they mislead most themselves or those with whom they are arguing. For it does not absolutely follow that all that is predicated of a class can also be predicated of all the individuals composing it; for the different particulars may belong to different individuals. For what hinders me, if I assume the same premiss, namely, that the Father is greater by Nature, and then add this other, Yet not by nature in every respect greater nor yet Father— from concluding, Therefore the Greater is not in every respect greater, nor the Father in every respect Father? Or, if you prefer it, let us put it in this way: God is an Essence: But an Essence is not in every case God; and draw the conclusion for yourself— Therefore God is not in every case God. I think the fallacy here is the arguing from a conditioned to an unconditioned use of a term, to use the technical expression of the logicians. For while we assign this word Greater to His Nature viewed as a Cause, they infer it of His Nature viewed in itself. It is just as if when we said that such a one was a dead man they were to infer simply that he was a Man.
XVI. How shall we pass over the following point, which is no less amazing than the rest? Father, they say, is a name either of an essence or of an Action, thinking to bind us down on both sides. If we say that it is a name of an essence, they will say that we agree with them that the Son is of another Essence, since there is but one Essence of God, and this, according to them, is preoccupied by the Father. On the other hand, if we say that it is the name of an Action, we shall be supposed to acknowledge plainly that the Son is created and not begotten. For where there is an Agent there must also be an Effect. And they will say they wonder how that which is made can be identical with That which made it. I should myself have been frightened with your distinction, if it had been necessary to accept one or other of the alternatives, and not rather put both aside, and state a third and truer one, namely, that Father is not a name either of an essence or of an action, most clever sirs. But it is the name of the Relation in which the Father stands to the Son, and the Son to the Father. For as with us these names make known a genuine and intimate relation, so, in the case before us too, they denote an identity of nature between Him That is begotten and Him That begets. But let us concede to you that Father is a name of essence, it will still bring in the idea of Son, and will not make it of a different nature, according to common ideas and the force of these names. Let it be, if it so please you, the name of an action; you will not defeat us in this way either. The Homoousion would be indeed the result of this action, or otherwise the conception of an action in this matter would be absurd. You see then how, even though you try to fight unfairly, we avoid your sophistries. But now, since we have ascertained how invincible you are in your arguments and sophistries, let us look at your strength in the Oracles of God, if perchance you may choose to persuade us out of them.
Source: Orations (New Advent)