1st. Unconscious cerebration expressing itself in unconscious muscular action. 2d. Psychic force. 3d. Spirits. I would remark that the first and second agree, in so far as they make the source of the phenomena internal; they differ in that the first would make them the result of a known law, the action of which had been previously detected, whilst the second supposes a previously unknown law or force of which spiritualistic phenomena are the sole evidence. I. The doctrine of unconscious cerebration is thus expressed by Dr. Carpenter (_Rep._, p. 272): "Ideational changes take place in the cerebrum, of which we may be at the time unconscious for want of receptivity on the part of the sensorium, but of which the results may at a subsequent period present themselves to the consciousness, as ideas elaborated by an automatic process of which we have no cognizance." Dr. Carpenter's ground for "surmising" that "ideational changes" may be received unconsciously, and subsequently recognized, and that the consciousness or unconsciousness of the reception depends upon their being presented or not in the sensorium, is the following analogy: The cerebrum, "or rather its ganglionic matter in which its potentiality resides," stands in precisely the same anatomical relation to the sensorium that the retina does; but visual changes may be unconsciously received in the retina when the sensorium is inoperative, and may be subsequently recognized. The reality of this automatic reception and elaboration of ideas is confirmed by the phenomena of somnambulism, which show "that long trains of thought may, with a complete suspension of the directing and controlling power of the will, follow the lead either of some dominant idea or of suggestion from without." This doctrine, when applied to explain the intelligent manifestations of spiritualism, comes to this, that you cannot argue, from the fact that a man informs you truly of something which he could not possibly have learned elsewhere, and which you know you were never aware of in the ordinary sense of the word, that he is informed by a superior intelligence; for you may have received unconsciously into your cerebrum the information in question, or have unconsciously elaborated it from premises so received, and may have communicated it to your informant by unconscious muscular action. I must do Dr. Carpenter the justice to admit that he nowhere, so far as I have seen, attempts to apply his doctrine in detail to the higher phenomena of spiritualism. He is contented with stating it as indicating the direction in which a solution of such phenomenal difficulties as do not seem to him wholly incredible is to be looked for.