SOPHEREUS. I accept your definition of the aims and methods of science. But what I find fault with is the assumption that we are not entitled to say that we know or believe a thing which can not be demonstrated as a scientific fact, when we are all the time grounding such knowledge or belief upon reasoning that convinces us of the truth and reality of other things which in like manner are not demonstrable as scientific facts. You may say that this is not the knowledge which we derive from scientific facts, and therefore it is not to be dignified by the name of knowledge. But we are always acting and must act upon proofs which are not scientific demonstrations; and whether we call this knowledge, or call it belief, we govern our lives according to it. We accept the proof that a buried city was the habitation and work of intelligent human beings, because we know that the forces of nature, not guided and applied by intelligent wills, never constructed a city. We accept the proof that men are just, merciful, courageous, truthful, or the reverse of all this, because their actions prove it, although we can not look into their hearts. What does all the estimate of the characters of men rest upon, but upon their actions? And is not this entitled to be ranked as knowledge of the characters of individual men? KOSMICOS. We must each retain his conclusions. Let our next discussion relate to the origin of the human mind, and then we shall see whether you will be able to resist the origin which evolution assigns to it. SOPHEREUS. I shall be glad to meet you again. CHAPTER XI. Origin of the human mind--Mr. Spencer's theory of the composition of mind--His system of morality. According to their appointment, our two disputants have met to discuss the origin of mind. SOPHEREUS. Will you begin this conference by stating the evolution theory of the origin of the human mind?