(from Prescription Against Heretics, c. 197 A.D.)
Now this heresy of yours does not receive certain Scriptures; and whichever of them it does receive, it perverts by means of additions and diminutions, for the accomplishment of it own purpose; and such as it does receive, it receives not in their entirety; but even when it does receive any up to a certain point as entire, it nevertheless perverts even these by the contrivance of diverse interpretations. Truth is just as much opposed by an adulteration of its meaning as it is by a corruption of its text. Their vain presumptions must needs refuse to acknowledge the (writings) whereby they are refuted. They rely on those which they have falsely put together, and which they have selected, because their ambiguity. Though most skilled in the Scriptures, you will make no progress, when everything which you maintain is denied on the other side, and whatever you deny is (by them) maintained. As for yourself, indeed, you will lose nothing but your breath, and gain nothing but vexation from their blasphemy.
Where diversity of doctrine is found, there, then, must the corruption both of the Scriptures and the expositions thereof be regarded as existing. On those whose purpose it was to teach differently, lay the necessity of differently arranging the instruments of doctrine. They could not possibly have effected their diversity of teaching in any other way than by having a difference in the means whereby they taught. As in their case, corruption in doctrine could not possibly have succeeded without a corruption also of its instruments, so to ourselves also integrity of doctrine could not have accrued, without integrity in those means by which doctrine is managed.
One man perverts the Scriptures with his hand, another their meaning by his exposition. For although Valentinus seems to use the entire volume, he has none the less laid violent hands on the truth only with a more cunning mind and skill than Marcion. Marcion expressly and openly used the knife, not the pen, since he made such an excision of the Scriptures as suited his own subject-matter. Valentinus, however, abstained from such excision, because he did not invent Scriptures to square with his own subject-matter, but adapted his matter to the Scriptures; and yet he took away more, and added more, by removing the proper meaning of every particular word, and adding fantastic arrangements of things which have no real existence.
Now, unquestionably, the Divine Scriptures are more fruitful in resources of all kinds for this sort of facility. Nor do I risk contradiction in saying that the very Scriptures were even arranged by the will of God in such a manner as to furnish materials for heretics, inasmuch as I read that “there must be heresies,” which there cannot be without the Scriptures.