You assert that our pretensions are false, for the simple reason that they _cannot be_ true! Very well. But, at all events, allow me to lay before you certain postulates. Suppose, in the first place, that you do not know everything, that the moral and even the material nature of man have obscurities which you have not been able to remove. Suppose that the smallest blade of grass springing up in the field, that the smallest grain reproducing its kind, that the finger of your hand in the act of executing the order you give it, enclose mysteries that surpass the powers of the learned doctors to fathom, and which they would declare absurd if they were not compelled to recognize them as real. Then, in the second place, suppose that certain men who will so to do, and whose hands are joined one to another in a certain way, give birth to a fluid or to a special kind of force. I do not ask you to admit that such force exists; you will only agree with me that it is possible. There is no natural law opposed to it that I know of. Now, let us take one more step. The will disposes of this fluid. It gives an impulse to external objects only when we will it, and in quarters selected by us. Would there be anything impossible in this? Is it an unheard-of thing that we transmit movement to matter that is outside of ourselves? Why, we do so every day, and every instant; our mechanical action is nothing more or less than this. The horrible thing in your eyes doubtless is that we do not act mechanically! But there is something besides mechanical action in this world. There are physical causes of movement that are something else than this. The caloric that penetrates a living body produces dilatation there; that is to say, universal movement. The loadstone placed in the neighborhood of a piece of iron attracts it, and makes it leap across the intervening space. "Yes," some one will exclaim, "we should make no objection, provided your pretended fluid did not obey one special direction in its progress. If it went straight on, as a blind force, well and good! It would then be like the caloric, that dilates everything it meets in its passage. It would be like the magnet which attracts indiscriminately toward a fixed point all the particles of iron in its vicinity. As for you, your invention of the theory of a rotative fluid calls vividly to mind the explanation of the dormitive properties of opium." It is impossible to more completely misunderstand things. No one dreams of a "rotative fluid." All we maintain is, that, when the fluid is emitted and imparts either repulsion or lateral attraction to a piece of furniture resting on legs, a very simple mechanical law transforms the lateral action into rotation.