Answer to Eunomius' Second Book
Now if the term ungenerate did not signify the being without origin, but the idea of simplicity entered into the meaning of such a term, and He were called ungenerate in their heretical sense, merely because He is simple and incomposite, and if the terms simple and ungenerate are the same in meaning, then too must the simplicity of the Son be equivalent with ungeneracy. For they will not deny that God the Only-begotten is by His nature simple, unless they are prepared to deny that He is God.
Accordingly the term simplicity will in its meaning have no such connection with being ungenerate as that, by reason of its incomposite character, His nature should be termed ungeneracy; or they draw upon themselves one of two absurd alternatives, either denying the Godhead of the Only-begotten, or attributing ungeneracy to Him also. For if God is simple, and the term simplicity is, according to them, identical with ungenerate, they must either make out the Son to be of composite nature, by which term it is implied that neither is He God, or if they allow His Godhead, and God (as I have said) is simple, then they make Him out at the same time to be ungenerate, if the terms simple and ungenerate are convertible.
But to make my meaning clearer I will recapitulate. We affirm that each of these terms has its own peculiar meaning, and that the term indivisible cannot be rendered by ungenerate, nor ungenerate by simple; but by simple we understand uncompounded, and by ungenerate we are taught to understand what is without origin. Furthermore we hold that we are bound to believe that the Son of God, being Himself God, is Himself also simple, because God is free from all compositeness; and in like manner in speaking of Him also by the appellation of Son we neither denote simplicity of substance, nor in simplicity do we include the notion of Son, but the term Son we hold to indicate that He is of the substance of the Father, and the term simple we hold to mean what the word bears upon its face.
Since, then, the meaning of the term simple in regard to essence is one and the same whether spoken of the Father or of the Son, differing in no degree, while there is a wide difference between generate and ungenerate (the one containing a notion not contained in the other), for this reason we assert that there is no necessity that, the Father being ungenerate, His essence should, because that essence is simple, be defined by the term ungenerate. For neither of the Son, Who is simple, and Whom also we believe to be generated, do we say that His essence is simplicity.
But as the essence is simple and not simplicity, so also the essence is ungenerate and not ungeneracy. In like manner also the Son being generated, our reason is freed from any necessity that, because His essence is simple, we should define that essence as generateness; but here again each expression has its peculiar force. For the term generated suggests to you a source whence, and the term simple implies freedom from composition. But this does not approve itself to them. For they maintain that since the essence of the Father is simple, it cannot be considered as other than ungeneracy; on which account also He is said to be ungenerate.
In answer to whom we may also observe that, since they call the Father both Creator and Maker, whereas He Who is so called is simple in regard to His essence, it is high time for such sophists to declare the essence of the Father to be creation and making, since the argument about simplicity introduces into His essence any signification of any name we give Him. Either, then, let them separate ungeneracy from the definition of the Divine essence, allowing the term no more than its proper signification, or, if by reason of the simplicity of the subject they define His essence by the term ungeneracy, by a parity of reasoning let them likewise see creation and making in the essence of the Father, not as though the power residing in the essence created and made, but as though the power itself meant creation and making.
But if they reject this as bad and absurd, let them be persuaded by what logically follows to reject the other proposition as well. For as the essence of the builder is not the thing built, no more is ungeneracy the essence of the Ungenerate. But for the sake of clearness and conciseness I will restate my arguments. If the Father is called ungenerate, not by reason of His having never been generated, but because His essence is simple and incomposite, by a parity of reasoning the Son also must be called ungenerate, for He too is a simple and incomposite essence.
But if we are compelled to confess the Son to be generated because He was generated, it is manifest that we must address the Father as ungenerate, because He was not generated. But if we are compelled to this conclusion by truth and the force of our premises, it is clear that the term ungenerate is no part of the essence, but is indicative of a difference of conceptions, distinguishing that which is generated from that which is ungenerate. But let us discuss this point also in addition to what I have said.
If they affirm that the term ungenerate signifies the essence (of the Father), and not that He has His substance without origin, what term will they use to denote the Father's being without origin, when they have set aside the term ungenerate to indicate His essence? For if we are not taught the distinguishing difference of the Persons by the term ungenerate, but are to regard it as indicating His very nature as flowing in a manner from the subject-matter, and disclosing what we seek in articulate syllables, it must follow that God is not, or is not to be called, ungenerate, there being no word left to express such peculiar significance in regard to Him.
For inasmuch as according to them the term ungenerate does not mean without origin, but indicates the Divine nature, their argument will be found to exclude it altogether, and the term ungenerate slips out of their teaching in respect to God. For there being no other word or term to represent that the Father is ungenerate, and that term signifying, according to their fallacious argument, something else, and not that He was not generated, their whole argument falls and collapses into Sabellianism.
For by this reasoning we must hold the Father to be identical with the Son, the distinction between generated and ungenerate having been got rid of from their teaching, so that they are driven to one of two alternatives: either they must again adopt the view of the term as denoting a difference in the attributes proper to either Person, and not as denoting the nature, or, abiding by their conclusions as to the word, they must side with Sabellius. For it is impossible that the difference of the persons should be without confusion, unless there be a distinction between generated and ungenerate.
Accordingly if the term denotes difference, essence will in no way be denoted by the appellation. For the definitions of difference and essence are by no means the same. But if they divert the meaning of the word so as to signify nature, they must be drawn into the heresy of those who are called “Son-Fathers,” all accuracy of definition in regard to the Persons being rejected from their account. But if they say that there is nothing to hinder the distinction between generated and ungenerate from being rendered by the term ungenerate, and that term represents the essence too, let them distinguish for us the kindred meanings of the word, so that the notion of ungenerate may properly apply to either of them taken by itself.
For the expression of the difference by means of this term involves no ambiguity, consisting as it does of a verbal opposition. For as an equivalent to saying “The Son has, and the Father has not, been generated,” we too assent to the statement that the latter is ungenerate and the former generated, by a sort of verbal correlation. But from what point of view a clear manifestation of essence can be made by this appellation, this they are unable to say. But keeping silence on this head, our novel theologian weaves us a web of trifling subtleties in his former treatise.
Because God, says he, being simple, is called ungenerate, therefore God is ungeneracy. What has the notion of simplicity to do with the idea of ungenerate? For not only is the Only-begotten generated, but, without controversy, He is simple also. But, says he, He is without parts also, and incomposite. But what is this to the point? For neither is the Son multiform and composite: and yet He is not on that account ungenerate.
Source: Answer to Eunomius' Second Book (New Advent)