21. It is possible, without doubt, to evade men of well-known malicious intentions; but how can we be preserved from the influence of undeveloped spirits which multiply around us, and glide everywhere without being seen?
The means are very simple; for it depends upon the will of the man himself, who carries within him the necessary instrument of protecting himself. Fluids unite by reason of the similitude of their nature, dissimilar ones repel each other. There is an incompatibility between good and bad fluids, as between oil and water.
What is done when the air becomes vitiated? They purify it by destroying the center of the miasma by chasing out the unhealthy effluvium by currents of salubrious air stronger than it. We need the good fluids in order to counteract the invasion of bad fluids; and, as each one has in his own perispirit a permanent fluidic-source, the remedy is within one’s self. It acts only to purify this source or spring, and to give to it such qualities as are necessary to repel bad influences, in place of being an attractive force. The perispirit is, then, a breastplate to which it is necessary to give the best possible character. Now, as the qualities of the perispirit correspond with the qualities of the soul, it is necessary to work for its own improvement; for it is the imperfections of the soul which attract bad spirits.
Flies go where centers of corruption attract them. Destroy these centers, and the flies will disappear. In the same way bad spirits go where evil attracts them. Destroy the evil, and they will flee. Spirits really good, whether incarnated or discarnated, have nothing to fear from the influence of bad spirits.