2 Then, in the next place, as to their saying that the Creator was ignorant of that deposit of seed which took place into him, and again, of that impartation of seed which was made by him to man, their words are futile and vain, and are in no way susceptible of proof. For how could he have been ignorant of it, if that seed had possessed any substance and peculiar properties? If, on the other hand, it was without substance and without quality, and so was really nothing, then, as a matter of course, he was ignorant of it.
For those things which have a certain motion of their own, and quality, either of heat, or swiftness, or sweetness, or which differ from others in brilliance, do not escape the notice even of men, since they mingle in the sphere of human action: far less can they [be hidden from] God, the Maker of this universe. With reason, however, [is it said, that] their seed was not known to Him, since it is without any quality of general utility, and without the substance requisite for any action, and is, in fact, a pure nonentity.
It really seems to me, that, with a view to such opinions, the Lord expressed Himself thus: “For every idle word that men speak, they shall give account on the day of judgment.” For all teachers of a like character to these, who fill men's ears with idle talk, shall, when they stand at the throne of judgment, render an account for those things which they have vainly imagined and falsely uttered against the Lord, proceeding, as they have done, to such a height of audacity as to declare of themselves that, on account of the substance of their seed, they are acquainted with the spiritual Pleroma, because that man who dwells within reveals to them the true Father; for the animal nature required to be disciplined by means of the senses.
But [they hold that] the Demiurge, while receiving into himself the whole of this seed, through its being deposited in him by the Mother, still remained utterly ignorant of all things, and had no understanding of anything connected with the Pleroma.
Source: Adversus haereses (New Advent)