518. Moreover, as he said, spirits also associate with spirits, and spirits with people on earth, which is not surprising considering they are so adept in imagery. But they have three signals to prevent them from saying more to them than they are allowed, namely, that they see a seemingly old man with a white face, which is a sign that they should not say anything but the truth. Therefore they are careful about what they say. The second sign is that a face appears as if through a window, which is a sign that they should depart and speak no more. An old man was seen also by me, afterwards a face as if through a window, and at once the spirit seemed to depart, nor did he venture to speak further with me by that kind of imagery.* * Paragraphs 517-18 have been placed, as indicated by the author, after 521.