455. For their tails were like unto serpents having heads, and with them they hurt, signifies the reason, because they are sensual and inverted, speaking truths with their lips, but falsifying them by the principle which constitutes the head of the doctrine of their religion, and thus they deceive. The like is here signified as above by the locusts (n. 438-439); but it is there said, that they had "tails like scorpions," whereas here, like "serpents," for they who are described by the locusts, speak and persuade from the Word, the sciences, and from erudition; but these only from arguments which are appearances of truth and fallacies; and they who use such arguments ingeniously, and as it were wisely, do indeed deceive, but not in so great a degree.
 By "serpent" in the Word, are signified sensual things, which are the ultimates of man's life, as above (n. 424); the reason is, because all animals signify the affections of man, wherefore also the affections of angels and spirits, in the spiritual world, appear at a distance as animals, and affections merely sensual, as "serpents"; and this because serpents creep on the ground and lick the dust, and sensual things are the lowest of the understanding and will, being in close contact with the world, and nourished by its objects and delights, which only affect the material senses of the body. Noxious serpents, which are of many kinds, signify the sensual things that depend on the evil affections which constitute the interiors of the mind with those who are insane from the falsities of evil; and harmless serpents signify the sensual things that are dependent on the good affections, which constitute the interiors of the mind with those who are wise from the truths of good.
 Sensual things dependent an evil affections, are signified by serpents in these passages:
They lick the dust like a serpent (Micah 7:17).
Dust shall be the serpent's bread (Isa. 65:25).
He said to the serpent, Upon thy belly shalt thou go, and dust shalt thou eat all the days of thy life (Gen. 3:14).
The sensual is thus described, which, because it communicates with hell, where all are sensual, turns heavenly wisdom into infernal insanity in spiritual things.
Be not glad, Philistia, for out of the serpent's root shall go forth a basilisk, whose fruit is a flying fiery serpent (Isa. 14:29).
They lay asp's eggs; he that eateth of its eggs dieth, and when one presses it out, a viper is hatched (Isa. 59:5).
Because the sons of Israel desired to return into Egypt, they were bitten by serpents (Num. 21:4-9).
"To return into Egypt," signified to become sensual from being spiritual; on which account it is said:
The hirelings of Egypt have turned themselves away, the voice thereof shall go like a serpent (Jer. 46:21-22).
 Because Dan was the farthest of the tribes, and thence signified the ultimate of the church, which is the sensual subject to the interiors, it is therefore said thus of him:
Dan is a serpent upon the way biting the horse's heels, and the rider shall fall backwards (Gen. 49:17).
By "the horse's heels" the ultimates of the understanding, which are sensual, are signified: by "biting" is signified to adhere to them: by "the rider" is signified the lack of knowledge from them, by which truths are perverted; for which reason it is said, "His rider shall fall backwards." Since sensual men are crafty and cunning like foxes, the Lord therefore says:
Be ye prudent as serpents (Matt. 10:16).
For the sensual man speaks and reasons from appearances and fallacies; and if he is skilled in the gift of arguing, he knows how to confirm every falsity skillfully, and also the heresy concerning faith alone, and still is so dull in the power of seeing truth that it is scarcely possible to be duller.