IN DISCUSSING the precautionary methods required in anticipatory observation it was necessary to touch on those necessary in true parapsychical experiment, so that there is now comparatively little to add. For all the precautions that apply to mere anticipatory observation naturally apply also to true experiment, in which, however, they can be practised even more strictly.
To experiment, in this connection, means for both the agent and the percipient consciously to make the attempt at a given moment to send and receive something specific. Thus both participants are 'active,' and even consciously active, though it is only the percipient who wants to receive. Here telepathy and thought-reading become one.
Comparatively few series of such experiments have been carried out, but these few are good; the experiments of Tischner, Wasielewski, Upton Sinclair, and others belong here, not to mention the various well-known S.P.R. series. The small number of these experiments is no doubt due to the fact that voluntary telepathy simply does not work with most people. As we have already seen, it is in all probability the subconsciousness that produces parapsychical phenomena, so that conscious volition is no more than an
indicium of the capacities of the subconsciousness. And, in fact, few people possess subconscious supernormal capacities which they can 'bring up' into consciousness.
The distance that separates the agent from the medium in good experiments is in itself an adequate precaution against apparently supernormal but really normal communication by the use of symbols of one kind or another. The same is true of hyperesthesia and of 'fishing.' Distance also excludes the possibility that the medium obtains private information. Errors of memory do not come into question on either side, since the notion transmitted is an actual one; an exception is presented by those few cases in which the percipient makes a wrong statement which represents, as the agent afterwards explains, the idea the latter had at first wanted to transmit and of which he consequently had an image in his consciousness.
The important criterion of coincidence in details, or at least in the general intuitive 'schema,' is present in what we call good cases. Naturally if a 'fish' is received instead of the 'picture of Christ' that was transmitted, this cannot be called a good case, even though the fish is undoubtedly a Christian symbol. Such interpretations are not permissible. Our motto must be 'the stricter the better,' or rather 'only good when strict.' I do not deny that a notion subconsciously received by the percipient may call up an association, and that this association alone may rise to consciousness; but the very vagueness of the so-called 'law of association by similarity and contrast' compels us to be very careful in applying it to our work. It is better to admit too little than too much.
It is hardly necessary to say that it would be very desirable to have a great number of good parapsychical cases of a genuinely experimental kind. Only it should not be thought that parapsychical experiments have been made and that no others are possible when a phenomenon that has the appearance of thought-transference has been obtained in a laboratory by normal means. A good many people have made this mistake: they have assumed that they have 'settled' psychical research when they have carried out experiments which have yielded results very valuable for the control of genuine parapsychical phenomena. In doing so they have 'settled' nothing at all, since those phenomena we regard as genuinely parapsychical take place under quite different but nevertheless adequately controlled conditions.
We have now described what precautions must be taken in the field of parapsychical phenomena before these phenomena can properly be regarded as genuine at all. The emphasis here is on the words 'at all.' It is precisely the object of the investigation to discover whether there is anything supernormal before us at all, whether there is anything not explicable on known and normal lines. But we have not yet entered on what we may call the higher problems, namely, those concerned with the question whether there are different classes of supernormal phenomena or whether all belong to one supernormal type. We have not yet ascertained, in other words, whether it is possible to reduce to a single class what appear at first sight to be different classes of facts. Hence we do not yet know what phenomena are entitled to rank as genuinely fundamental, in Goethe's sense, and whether there are several such fundamental phenomena or only one.
But before we enter on these higher inquiries it is necessary to add two sections to our investigation of the precautions needed for the establishment as genuine of supernormal phenomena: we have expressly to deprecate both inadequate and exaggerated