Professor Grasset’s case is, however, instructive. I consider him as one of our best-informed scientists, and he seems to look upon psychical research without prejudice. Nobody can doubt his earnestness, his learning, his talent; but, in spite of these qualities, he shows himself to be unfamiliar with the serious work which has been done, and which is being done in psychical matters. When he quotes Myers, he misquotes him. When he discusses the Piper case, he sums up the account given of the case by M. Mangin in the _Annales des Sciences Psychiques_, and does not say a word of the careful reports drawn up by Hodgson and Hyslop. It is not to be wondered at, therefore, if the professor’s statements do not agree with the facts. He does not appear to have studied either the original reports or M. Sage’s remarkable summary of these reports. Professor Grasset simply says: ‘Four months after the death of Mr. Robinson (George Pelham), Mrs. Piper gave a seance in the house of one of Mr. Robinson’s friends and fell into a trance.’ [A slight mistake, the seance took place at Mrs. Piper’s.] ‘P., the secondary personality, said that George Robinson was ready to communicate; and henceforth this spirit took part in Mrs. Piper’s seances as another familiar spirit. Such an example shows how _polygonal_ incarnations are formed during the medium’s trance.’ And no more! Professor Grasset does not see the real problem: did the medium show any knowledge of facts known only to the deceased? This is the problem. The mode of formation of the secondary personality is but an accessory question. This kind of reasoning is common to savants. They keep aloof from the real psychological problem, and only discuss its side issues. I am sorry to see a man of Professor Grasset’s worth fall into the usual errors, and pronounce a judgment upon facts before thoroughly acquainting himself with those facts. Professor Grasset speaks of _spiritisme scientifique_ as belonging to the realm of biology, and demanding the serious attention of scientists. But why speak of spiritism? Spiritism is a religion, it is not a science; it is the _systematic explanation_ of the _ensemble_ of certain facts, so far very ill understood, but it is not the assertion of those facts. Are the alleged facts true? That is the question which biology has to examine. Spiritism, on the contrary, that is to say, the _ensemble_ of metaphysical doctrines founded upon the revelations of spirits, cannot be considered, at least for the present, as belonging to biology. I beg Professor Grasset not to confound the impartial, unbiased research for scientific truth with spiritism.