_Büchner._ Yet “the theory that the brain is the seat of the soul is so incontrovertible that it has long been adopted in the rules of law in regard to monstrosities. A monstrosity with one body and two heads counts for _two_ persons; one with two bodies and one head, only for one person. Monstrosities without brain, so‐called acephali, possess no personality” (pp. 147, 148). _Reader._ This is true; and therefore the soul certainly informs the brain. But it does not follow that other parts of the body are not informed. Hence your remark has no bearing on the question; and it remains true that the soul, as the form of the body, is directly connected with every part of the organism in which vital acts are performed. XV. Spiritism. _Reader._ May I ask, doctor, what you think of spiritism? _Büchner._ I think it to be a fraud. _Reader._ Of course, when a man denies the existence of spiritual substances, he cannot but deny their manifestation. Yet the phenomena of spiritism are so well known that we can scarcely be of your opinion. _Büchner._ “Some of these phenomena, _clairvoyance_ especially, have been laid hold of to prove the existence of supernatural and supersensual phenomena. They were considered as the link of connection between the spiritual and the material world; and it was surmised that these phenomena opened a gate through which man might pass, and succeed in obtaining some immediate clue regarding transcendental existence, personal continuance, and the laws of the spirit. All these things are now, by science and an investigation of the facts, considered as idle fancies which human nature is so much inclined to indulge in to satisfy its longing after what appears miraculous and supersensual” (p. 149). _Reader._ I apprehend, doctor, that science has no means of showing that “all these things are idle fancies.” Materialism, of course, assumes, though it cannot show, that spirits do not exist; but materialism is no science at all; and if the “investigation of the facts” has been conducted by materialists, we may well be sure that their verdict was not unbiassed. On the other hand, men of science, who are not materialists, a great number of physicians, philosophers, and theologians, are convinced that the phenomena of spiritism are neither inventions nor delusions. And, though human nature feels a certain propensity to believe what is wonderful, we cannot assume that learned and prudent men yield to this propensity without good reasons.