The Manichaean religious formulae cannot thrust out the power of Evil.

But if they persist in holding this (theory of a) Mixing, that (explanation) fails inasmuch as by our Will we conquer Evil, and, therefore, instead of 'the Good Words' which they teach they ought to distribute good Parts that mankind may eat or drink them that those good Parts may enter and lessen the fierceness of Evil. For words do not lessen the bitterness of roots ; but the (natural) acridness which is in a Nature is lessened by the (natural) sweetness which is in (another) element. For facts are not overcome by Words, nor by Expressions are Natures changed. For that Evil which exists independently, as they say, can be thrust out by means of some Good which also exists independently. For Power thrusts out Power and Substance is thrust out by Substance and Force is conquered by Force. Yet our (mere) Word cannot stir a stone without the hand, nor can our Will move anything without our arms. And if our Will is not able to move such insensible and helpless things, how can it vanquish the great Evil, seeing that a Power is required and not (mere) Will ? For Light does not drive out Darkness by Will, nor by Free-choice does the sweet overcome the bitter. If, therefore, these Natures, because they are Natures, require a powerful Force and not a mere Will, how is it that the quality of Power, not (mere) Free-choice, is not required in the case of Evil and Good, if they have 'bound Natures' ?