1983. Evil spirits have a strong and burning desire to molest and attack man when he is asleep, but at that time man is especially protected by the Lord, for love does not sleep. Spirits who molest are punished piteously. I have heard their punishments more often than I can repeat. These involve being torn apart, as described in 829, 957, 959, which is carried out below the heel of the left foot, lasting sometimes for hours on end. Sirens, who inwardly are witches, are those who especially lie in wait in the night, and then try to worm their way into a person's inward thoughts and affections. But as often as they try to do so they are foiled by angels from the Lord and at length are deterred by means of very drastic punishments. 'These sirens have also spoken to others in the night, when they have impersonated me so perfectly and imitated my speaking so accurately that no one could tell the difference, and in so doing have poured in filthy thoughts and suggested ideas that were false.
[2] I was once sleeping very soundly, in an altogether sweet repose. When I awoke certain good spirits began to accuse me of having molested them, so violently, they said, that they thought they had been in hell; they put the blame on me. I answered them that I knew nothing whatever about the matter, but that I had been fast asleep and therefore could not possibly have been the one to molest them. At this they were dumbfounded and at length realized that those sirens had been up to their tricks. Something similar was also demonstrated to me after that so that I might know what that band of sirens is like.
[3] These sirens are mainly females, who during their lifetime have studied how to attract male companions to themselves by interior devices - by worming their way in through external allurements, by captivating the baser mental instincts in all sorts of ways, by penetrating into each one's affections and delights, but with an evil motive, namely that of manipulating. Their nature is such in the next life therefore that they seem to be able of themselves to do anything. They take in from others and think up for themselves different devices which they absorb with ease like sponges soaking up water, filthy or clean alike. They accordingly soak up and practice what is profane as well as what is holy with the intent, as stated, of manipulating. I have been allowed to perceive how foul they are inwardly, polluted by adultery and hatred. I have also been given to perceive how overpowering their sphere is. These sirens force their own interior thought and feelings into a state of persuasion, so that these may go hand in glove with their exterior thought and feelings towards the things they intend. In this way sirens compel and lead spirits to think as they themselves do.
[4] No reasonings are in evidence among them, and yet they employ a whole mass of reasonings that are breathed into people's evil affections by applying themselves to those persons' natural instincts. In this way they gain entry into the baser parts of the minds of others whom they lead on and by persuasion either overwhelm or captivate. There is nothing they study more than how to destroy conscience, and when they have destroyed it gain possession of people interiorly and even obsess them, though the individual is not conscious of it. Nowadays external obsession is not allowed as it once was in former times, but internal possession by spirits such as these does take place. People who are devoid of conscience are obsessed in this way. The interior aspects of their thought are insane in a very similar way, but those aspects are concealed by and covered with an outward propriety and presence of honesty displayed for the sake of personal position, wealth, and reputation. This they can even recognize for themselves if they pay any attention to what they think.