This was a certain and undeniable case, and Sully-Prudhomme returned to his home with me as thoroughly convinced as I am. The poet of _Solitudes_ and of _Justice_, wrote on his part, as follows: After a rather long wait, an architect's stool came marching up all alone toward me. It grazed my left side, rose to the height of the table, and succeeded in placing itself upon it. As I lifted my hand, I felt it at once seized. "Why do you take my hand?" I asked of my neighbor. "It was not I," said he. While these phenomena were taking place, Eusapia seemed to be suffering. It seemed as if out of her own physiological fund or stock she were furnishing all the force required to put the objects in motion. After the seance, while she was still very much prostrated, we saw an easy-chair which was behind the curtain come rolling up behind her, as if to say, "Hold on there! you've forgotten me!" My conviction is that I witnessed phenomena which I cannot relate to any ordinary physical law. My impression is that fraud, in any case, is more than improbable,--at least so far as concerns the displacement at a distance of heavy articles of furniture arranged by my companions and myself. That is all that I can say about it. For my part, I call "natural" that which is scientifically proved. So that the word "mysterious" means that which still astonishes us because it cannot be explained. I believe that the scientific spirit consists in verifying facts, in not denying _a priori_ any fact which is not in contradiction with known laws, and in accepting none which has not been determined by safe and verifiable conditions.