646. Moreover there is nothing whatever that affects the senses, whether exteriorly or interiorly, upon which spirits do not strive to induce a similar shape, so that they imitate anything whatever that they see and feel, and counterfeit it as if it were the essential thing itself, when, nevertheless, it is only something external and fictitious. It is, therefore, a matter of the greatest prudence to distinguish between what is true and what is counterfeit; and they can never be distinguished except through faith in the Lord, and thus from the Lord, Who gives the ability to discern between things that are similar. The same is true in the life of the body when such genii are present and try to seduce man. 1748, Feb. 5.