
Jerome
Catena Aurea · Matthäusevangelium 12
Either make the tree good, and his fruit good; or else make the tree corrupt, and his fruit corrupt: for the tree is known by his fruit. O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh. A good man out of the good treasure of the heart bringeth forth good things: and an evil man out of the evil treasure bringeth forth evil things.
Thus He holds them in a syllogism which the Greeks call ‘Aphycton,’ the unavoidable; which shuts in the person questioned on both sides, and presses him with either horn. If, He saith, the Devil be evil, he cannot do good works; so that if the works you see be good, it follows that the Devil was not the agent thereof. For it cannot be that good should come of evil, or evil of good.