_Reader._ You are quite mistaken. The brain is an organ of the imagination, not of the intellect. And even as an organ of imagination it is incompetent to think or imagine, as it is only the instrument of a higher power—that is, of a soul. To say that the brain is the organ of intellectual thought is to assume that intellectual relations are pictured on the brain; which is evidently absurd, since intellectual relations cannot be pictured on material organs. Every impression made on our brain is a definite impression, corresponding to the definite objects from which it proceeds. If our intellectual thought were a function of the brain, we could not think, except of those same definite objects from which we have received our definite impressions. How do you, then, reconcile this evident inference with the fact that we conceive intellectually innumerable things from which we have never received a physical impression? We think of justice, of humanity, of truth, of causality, etc., though none of these abstractions has the power to picture itself on our brain. It is therefore impossible to admit that the intellectual thought is a function of the brain. With regard to the working of the imagination, I concede that the brain plays the part of an instrument; but how can you explain such a working without a higher principle? If our soul is nothing but “a product of matter,” since matter is inert, our soul must be inert, and since matter has only mechanical powers, our soul must be limited to mechanical action, that is, to the production of local movement. Now, can you conceive imagination as a merely mechanical power, or thought as the production of local movement? _Büchner._ Yes. “Thought,” says Moleschott, “is a motion of matter” (p. 135). _Reader._ It is perfectly useless, doctor, to make assertions which cannot be proved. Moleschott is no authority; he is a juggler like yourself, and works for the furtherance of the same Masonic aims. Let him say what he likes. We cannot but laugh at a thinker who can mistake his thought for local motion. _Büchner._ You, however, cannot deny that, while we are thinking, our brain is doing work. But how can it do work without motion?