1182. Verse 21. And one strong angel took up a stone like a great millstone and cast into the sea, signifies confirmations of their doctrine from the Word cast with them into hell. This is evident from the signification of "strong angel," as being the Divine truth in its power (see n. 130, 200, 302, 593, 800); also from the signification of a "millstone," as being the confirmation of truth from the Word, and also the confirmation of falsity from the Word (of which presently); also from the signification of "casting into the sea," as being into hell with them; that the "sea" signifies hell, may be seen (n. 537, 538). A "millstone" signifies confirmation from the Word in both senses, because "wheat" signifies good, and "fine flour" its truth, therefore "a millstone," by which wheat is ground into fine flour, or barley into meal, signifies the production of truth from good, or the production of falsity from evil, so, too, the confirmation of truth or of falsity from the Word; as can be seen from the following passages. In Jeremiah:
I will take away from them the voice of joy and the voice of gladness, the voice of the bridegroom and the voice of the bride, the voice of the millstones and the light of the lamp (Jeremiah 25:10).
Here, too, the joy of heaven and of the church is described, and "the voice of joy" signifies exultation of heart from the good of love, and "the voice of gladness" signifies glorification of soul from the truths of faith, for in the Word "joy" is predicated of good, and "gladness" of truth. "The voice of millstones" has a similar signification as "the voice of joy;" and "the light of the lamp" has a similar signification as "gladness," namely, from the truth of faith. "The voice of millstones" signifies joy of heart from the good of love, because a millstone grinds wheat into fine flour, and "wheat" signifies the good of love, and "fine flour" truth from that good.
 Like things are said in this chapter of Revelation, namely:
The voice of a millstone shall not be heard in thee anymore, and the light of a lamp shall not shine in thee anymore, and the voice of bridegroom and the voice of bride shall not be heard in thee anymore (Revelation 18:22-23).
These words will be explained presently. In Isaiah:
Take the millstone and grind meal, make bare the thigh passing through the rivers (Isaiah 47:2).
This is said of Babylon and Chaldea; and "to take the millstone and grind meal," signifies to bring forth falsities from evil, and to confirm them by means of the Word; and "to make bare the thigh passing through the rivers," signifies to adulterate goods by means of reasonings. In Lamentations:
The young men they led away to grind, and the boys stumbled under the wood (Lamentations 5:13).
"To lead away the young men to grind," signifies to compel those who are capable of understanding truths to falsify truths; "the boys stumble under the wood," signifies to compel those who are capable of willing goods to adulterate goods, "to grind" being to falsify truths or to confirm falsities by means of the Word, "wood" being good. In Moses:
Thou shalt not take the mill or the upper millstone for a pledge, for He receiveth the soul for a pledge (Deuteronomy 24:6).
This was among their laws, all of which corresponded to spiritual things. "Not to take a mill or millstone for a pledge" signified in the spiritual sense that the ability from good to understand truths must not be taken away from anyone, thus that no one must be deprived of goods and truths. Because this is the signification it is said, "for he receiveth the soul for a pledge," which signifies that thus one would spiritually perish. In the same:
They shall die even to the firstborn of the maidservant that is behind the mill (Exodus 11:5).
"The firstborn of the maidservant that is behind the mill" signifies the chief things of faith of the natural man, that have been falsified.
(References: Matthew 24:40-41)
 In Matthew:
In the end of the age two women shall be grinding, one shall be taken and the other shall be left (Matthew 24:40, 41).
"The end of the age" is the last time of the church; "the two women grinding" mean those who confirm themselves in truths and those who confirm themselves in falsities from the Word; those who confirm themselves in truths are meant by the one that shall be taken, and those who confirm themselves in falsities by the one that shall be left. In the Gospels:
Jesus said, Whoso shall cause one of these little ones that believe in Me to stumble, it is profitable for him that an ass-millstone be hanged about his neck, and that he be sunk in the depths of the sea (Matthew 18:6; Mark 9:42; Luke 17:2).
"To cause one of the little ones that believe in Jesus to stumble," signifies to pervert those who acknowledge the Lord; "it is profitable that an ass-millstone be hanged about the neck," signifies that it would be better for him not to know any good and truth, but only evil and falsity; this is meant by "ass millstone," and "to be hanged about the neck" means cutting one off from knowing good and truth; "to be sunk in the depths of the sea," signifies to be cast down to hell. This is profitable because to know goods and truths and to pervert them is to profane. What is meant by:
Moses burnt the calf and ground it even to powder, and sprinkled it upon the face of the waters, and made the sons of Israel to drink of it (Exodus 32:20; Deuteronomy 9:21),
may be seen explained in the Arcana Coelestia 10462-10466).
 Something shall now be said about the speech of spirits with man. Many believe that man can be taught by the Lord by means of spirits speaking with him; but those who believe this and are willing to believe it do not know that it is attended with danger to their souls. So long as man is living in the world, as to his spirit he is in the midst of spirits, although spirits do not know that they are with man, nor does man know that he is with spirits; and for the reason that as to the affections of the will they are immediately conjoined, while as to the thoughts of the understanding they are mediately conjoined. For man thinks naturally, but spirits think spiritually; and natural and spiritual thought make one only by correspondences; and in a oneness by correspondences neither one of the two knows anything about the other. But as soon as spirits begin to speak with man they come out of their spiritual state into man's natural state, and they then know that they are with man and they conjoin themselves with the thoughts of his affection and speak with him from those thoughts. They can enter into no other state of man, for all conjunction is by like affection and thought therefrom, while unlike separates. For this reason the speaking spirit must be in the same principles as the man is, whether they be true or false; and these he stirs up, and through his affection conjoined to man's affection he strongly confirms them. This makes clear that none but like spirits speak with man, or manifestly operate into him, for manifest operation coincides with speech. Consequently only enthusiastic spirits speak with enthusiasts; only Quaker spirits operate upon Quakers, and only Moravian spirits upon Moravians. The same is true of Arians, Socinians, and other heretics.
 All spirits that speak with man were once men in the world, and were then of like character. This has been granted me to know by repeated experience. And what is absurd, when a man believes that the Holy Spirit is speaking with him or operating upon him the spirit also believes himself to be the Holy Spirit. This is common with enthusiastic spirits. All this shows the danger in which a man is who speaks with spirits, or who manifestly perceives their operation. Man does not know what the quality of his affection is, whether it be good or evil, or with what others it is conjoined; and if he is in the pride of self-intelligence the spirit within him favors every thought from that source; and the same is true when one favors certain principles enkindled by such a fire with those who are not in truths from genuine affection. Whenever a spirit from like affection favors man's thoughts or principles, one leads the other as the blind lead the blind until both fall into the pit. The Pythonists formerly were of this character, also the magi in Egypt and in Babylon, who were called wise because they talked with spirits, and because they clearly perceived the operation of spirits in themselves. But by this the worship of God was changed into the worship of demons, and the church perished. For this reason such interaction was forbidden to the sons of Israel under penalty of death.
(References: Revelation 18:21-23)