Passing next to the most interesting of spiritualistic 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 proven that it is almost impossible not to give some indication of one's thoughts, when put upon the strain; and that under excitement, these indications may become 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 clue from indications which his subject is "absolutely confident he did not give." The assurances of sitters that _they know_ they did not move the table are equally valueless; and 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 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 a 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. Davey, above referred to, the sitters prepared accounts of the "slate-writing" manifestations they had witnessed, and described marvels that had not occurred, but which they were convinced they had seen--messages written on slates utterly inaccessible to Mr. Davey, 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 given to a certain point in another place--nothing of which any one needs feel ashamed, something which it requires unusual training and natural gifts to avoid. The mistake lies in not recognizing our liability to such error.