8 As to the point, then, that their system is weak and untenable as well as utterly chimerical, enough has been said. For it is not needful, to use a common proverb, that one should drink up the ocean who wishes to learn that its water is salt. But, just as in the case of a statue which is made of clay, but coloured on the outside that it may be thought to be of gold, while it really is of clay, any one who takes out of it a small particle, and thus laying it open reveals the clay, will set free those who seek the truth from a false opinion; in the same way have I (by exposing not a small part only, but the several heads of their system which are of the greatest importance) shown to as many as do not wish wittingly to be led astray, what is wicked, deceitful, seductive, and pernicious, connected with the school of the Valentinians, and all those other heretics who promulgate wicked opinions respecting the Demiurge, that is, the Fashioner and Former of this universe, and who is in fact the only true God— exhibiting, [as I have done,] how easily their views are overthrown.
Source: Adversus haereses (New Advent)