them; while, as a matter of fact, the laxity of most investigators in this regard is well known. These performances deceive because people overlook the technical acquisitions needed to pronounce upon the possibility or impossibility of a fastening being undone and apparently restored without detection. If manufacturers of safes were equally credulous, and gave equally little time to the study of the security of locks, "a safe" would be an ironical expression indeed.
Passing next to the most interesting of spiritual manifestations, those in which self-deception comes to the foreground, I need hardly dwell at length upon the tilting of tables, the production of raps by movements of which the sitters are unconscious; for these have been so often and so ably presented that they must now be well understood. Suffice it to say that it has been objectively proved that it is almost impossible not to give some indication of one's thoughts when put upon the strain; and that, when excited, these indications may be palpably plain and yet remain unperceived by the individual who gives them. The extreme subtlety of these indications is met by the unusual skill of the professional "mind-reader," who takes his clew from indications which his subject is "absolutely confident he did not give." The assurance of sitters that they know they did not move the table is equally valueless, and here nothing but objective tests will suffice. The most wholesome lesson to be derived from the study of these phenomena is the proof that not all our intentions and actions are under the control of consciousness, and that, under emotional or other excitement, the value of the testimony of our consciousness is very much weakened. Again, it is almost impossible to realize the difficulty of accurately describing a phenomenon lying outside the common range of observation. Not alone that the knowledge necessary to pronounce such and such phenomenon impossible of performance by conjuring methods is absent, but with due modesty and most sincere intentions the readiness with which the observing powers and the memory play one false is overlooked. In the investigation of Mr. Davies, above referred to, the sitters prepared accounts of the "slate-writing" manifestations they had witnessed, and described marvels that they had not seen but which they were convinced they had seen—writing on slates utterly inaccessible by Mr. Davies, and upon slates which they had noticed a moment before were clean. The witnesses are honest; how do these mistakes arise? Simply a detail omitted here, an event out of place there, an unconscious insertion in one place, an undue importance to a certain point in another place—nothing of which any one need feel ashamed; something which it requires unusual training and a natural bent to avoid. The mistake lies in not recognizing our liability to such error.
