There is an important general observation to be made concerning the phenomena I am treating in this book. It is of historical order, but nevertheless it gives a much wider signification to these facts than is usually accorded them. Many writers, Janet among them, imagine that _spiritistic_ phenomena, as they call them, date from the celebrated events of Rochester, about the year 1847, where the Fox sisters were the objects of diverse manifestations. But in reality these facts date much further back. One of the best observed cases is the one spoken of by Dr. Kerner in his book _Die Seherin von Prevorst_, which has been translated by Dr. Dusart into French, probably from Mrs. Crowe’s English translation. Kerner observed raps and movements without contact from the year 1827, when he had Madame Hauff staying in his house. Phenomena of the same kind are to be met with in accounts of haunted houses. There are stories of this kind dating from remote epochs, and diverse decrees of parliament exist cancelling leases for this cause. These phenomena were criticised at the end of the eighteenth century. It is only the metaphysical system founded upon these facts which is new. It is in that, and in that only, that spiritism or spiritualism consists. It is undeniable that the doctrine embodying the essence of these teachings has attained a considerable extension. I pointed out the radical differences existing between the beliefs of Anglo-Saxon spiritists and those of spiritists of other nationalities, particularly in that which concerns reincarnation. I will not go back to this; but in order to specify the point in question, I will recall to mind that the only new phenomena which spiritistic forms of contemporary mysticism offer, are their constitution into a body of religious doctrines and their rapid extension. These phenomena are of sociological, not biological order. The facts upon which they are based belong, on the contrary, to biology.