Against The Valentinians by Tertullian
Chapter XI.--The Profane Account Given of the Origin of Christ and the Holy Ghost Sternly Rebuked An Absurdity Respecting the Attainment of the Knowledge of God Ably Exposed.
Accordingly, after the banishment of the Enthymesis, and the return of her mother Sophia to her husband, the (illustrious) Monogenes, the Nus, released indeed from all care and concern of the Father, in order that he might consolidate all things, and defend and at last fix the Pleroma, and so prevent any concussion of the kind again, once more emits a new couple (blasphemously named). I should suppose the coupling of two males to be a very shameful thing, or else the one must be a female, and so the male is discredited by the female. One divinity is assigned in the case of all these, to procure a complete adjustment among the Æons. Even from this fellowship in a common duty two schools actually arise, two chairs, and, to some extent, the inauguration of a division in the doctrine of Valentinus. It was the function of Christ to instruct the Æons in the nature of their conjugal relations (you see what the whole thing was, of course!), and how to form some guess about the unbegotten, and to give them the capacity of generating within themselves the knowledge of the Father; it being impossible to catch the idea of him, or comprehend him, or, in short, even to enjoy any perception of him, either by the eye or the ear, except through Monogenes (the Only-begotten). Well, I will even grant them what they allege about knowing the Father, so that they do not refuse us (the attainment of) the same. I would rather point out what is perverse in their doctrine, how they were taught that the incomprehensible part of the Father was the cause of their own perpetuity, whilst that which might be comprehended of him was the reason of their generation and formation. Now by these several positions the tenet, I suppose, is insinuated, that it is expedient for God not to be apprehended, on the very ground that the incomprehensibility of His character is the cause of perpetuity; whereas what in Him is comprehensible is productive, not of perpetuity, but rather of conditions which lack perpetuity -- namely, nativity and formation. The Son, indeed, they made capable of comprehending the Father. The manner in which He is comprehended, the recently produced Christ fully taught them. To the Holy Spirit, however, belonged the special gifts, whereby they, having been all set on a complete par in respect of their earnestness to learn, should be enabled to offer up their thanksgiving, and be introduced to a true tranquillity.