340. Small and large societies, and all reunions, whatever be their importance, have to contend with another danger. The fomentors of discord are not only within them, they are in the invisible world as well. As there are spirit protectors for societies, cities, and nations, so bad spirits attach themselves to groups as to individuals ; they first attack the weakest, the most accessible, of whom they endeavor to make instruments, and gradually try to circumvent the masses ; for their wicked joy increases according to the number they can subjugate. So, whenever one person of a group has fallen into a snare, say at once, an enemy is in the camp, —a wolf in the sheepfold, — and we must be on our guard, for it is most probable he will multiply his attempts ; if he is not discouraged by an energetic resistance, the obsession then becomes like a contagious disease, which is manifested among the mediums by pertuibation of mediumship, and among others by hostility of sentiment, perversion of the moral sense, and a breaking up of the harmony. As the most powerful antidote to this poison is charity, it is charity they will seek to stifle. No waiting until the evil has become incurable in order to bring a remedy for it, no waiting even for the symptoms, but by every means endeavor to prevent it ; for this there are two efficacious means, that may be well employed : prayer from the heart, and the attentive study of the least signs that reveal the presence of deceiving spirits ; the first attracts good spirits who zealously assist those who second them by confidence in God ; the other proves to the bad ones that they have to do with persons clear-sighted and sensible enough not to allow themselves to be deceived. If one of the members yields to the influence of the obsession, every effort, from the first symptoms, should tend to open his eyes, lest the evil should increase, then to convince him that he is deceived, and lead him to desire to second those who wish to help him.