590. Comparisons will illustrate what a person is like whose understanding is raised without this in turn raising the love of his will. He is like an eagle flying high, which as soon as it sees its prey below, such as chickens or cygnets or even young lambs, swoops down at once and devours them. He is also like an adulterer, who hides his whore downstairs in the cellar, but from time to time comes upstairs to the upper part of the house, and in his wife's presence talks wisely with his visitors about chastity, and then from time to time breaks off the discussion and satisfies his lust down below with his whore. He is also like the flies in a marsh, which fly in a column over the head of a galloping horse, but when the horse keeps still, drop down and plunge into the marsh where they live. Such is the nature of a person whose understanding is raised up high, but who has the love of his will kept down at foot level, immersed in the filth of nature and the lusts of the senses.
[2] But because they have this gleam in their understanding which looks like wisdom, though their will is opposed to it, they can be likened to snakes with glistening scales, Spanish flies that glitter as if with gold, or to the will-o'-the-wisp of marshland, rotten wood that shines in the dark, and phosphorescent substances. There are some of them who can imitate angels of light, both among people in the world and after death in the presence of angels of heaven. But after a short period of examination they are stripped of their clothes and cast down naked. Nothing of the sort, however, can happen in the world, because there their spirit is not open to view, but is overlaid with a disguise, like those used by actors on the stage. Their being able to imitate angels of light in countenance and expression is the reason and also a sign, that they can raise their understanding almost to the point of angelic wisdom, rising as I have said above the love of the will. Now since a person's internal and external can thus go in opposite directions, and since the body is discarded and the spirit remains, it is clear that a murky spirit can live behind a shining face, and a fiery one behind a smooth tongue. Therefore, my friend, you must get to know a person not by his mouth but by his heart, that is, not by his conversation but by what he does. For the Lord says:
Beware of false prophets who come to you in sheep's clothing, but inwardly are ravening wolves; by their fruits you must know them. Matt. 7:15, 16.