186. It would then be an error, if, having at hand a good medium, even one who writes with the utmost facility, we should from that alone expect to obtain good communications of all kinds. The primary condition certainly is, to be assured of the source where they emanate, that is, of the qualities of the spirit who transmits them ; but it is not the less necessary to be careful of the qualities of the instrument given to the spirit: we must, then, study the nature of the medium,as we study the nature of the spirit, for these are the two essential elements for obtaining a satisfactory result. There is a third, that plays an equally important part—the intention, the secret thought, the more or less praiseworthy sentiment of the interrogator; and so it may be said, To obtain agood communication, it must emanatefrom agood spirit; that this good spirit may be able to transmit it, he must have a good instrument ; that he may desire to transmit it, the motive must suit him.
The spirit, who reads in the thought, judges if the question proposed merits a serious answer, and if the person who addresses him is worthy to receive it: in a contrary case, he does not- lose his time sowing good seed on stony ground; and then trifling, mock- ing, spirits take his place, because, troubling themselves very little about the truth, they do not look at things so closely, and are usually but little scrupulous as to the end or means.-
We here sum up the principal kinds of mediumship, before presenting a kind of synoptical list, comprising those we have already described in the preceding chapters, indicating the numbers of those to which we shall add further details.
We have grouped the different varieties of mediums by analogy with causes and effects, but do not propose there shall be anything absolute in this classification. Some are frequently met, others are rare and exceptional, which we have taken care to mention. These last indications have all been furnished by spirits, who, besides, have reviewed this descriptive list with an exceedingly particular care, and have completed it by numerous observations and new categories, so that it may be said to be their entire work. We have indicated by quotation marks their textual observations when we have thought it necessary to make them more prominent. They are mostly from Erastus and Socrates.