_Reader._ Why, then, do you bring them forward? _Büchner._ “The facts of science prove with considerable certainty that the organic beings which people the earth owe their origin and propagation solely to the conjoined action of natural forces and materials, and that the gradual change and development of the surface of the earth is the sole, or at least the chief, cause of the gradual increase of the living world” (p. 72). _Reader._ This is another of your vain assertions. For you confess that “it is impossible at present to demonstrate with scientific exactness” the gradual development of organic beings from mere material forces; and you had previously affirmed that “there _must_ have existed individuals of the same species, to produce others of the same kind” (p. 68). Where are, then, to be found the facts of science which “prove with considerable certainty” the contrary of what you acknowledge to be the fact? Is your method of reasoning a mere oscillation between contradictories? _Büchner._ “We may hope that future investigations will throw more light on the subject” (_ibid._) _Reader._ Very well. But, if this is the case, surely no “fact of science” proves, as yet, the spontaneous evolution of life from inorganic matter. And you may be certain that the future investigations of science will not give the lie to the investigations of the past. _Büchner._ “Our present knowledge is, however, sufficient to render it highly probable, nay, perhaps morally certain, that a spontaneous generation exists, and that higher forms have gradually and slowly become developed from previously existing lower forms, always determined by the state of the earth, but without the immediate influence of a higher power” (_ibid._) _Reader._ All this I have already answered; and I am rather tired, doctor, of repeating the same remarks over and over again. Why should you make these empty assertions, if you had real arguments to produce? And, if you have no arguments, what is the use of saying and gainsaying at random, as you do, the same things? Why do you assert that “the immediate influence of a higher power” has nothing to do with the origin of life, when you know that your assertion must remain unproved and can easily be refuted? If “our present knowledge renders it highly probable, nay, perhaps, morally certain, that a spontaneous generation exists,” why did you say the contrary just a few lines before? It is inconceivable that a thinking man should be satisfied with such a suicidal process of arguing. _Büchner._ “The law of a gradual development of primeval times is impressed upon the present living organic world” (p. 75). “All animal forms are originally so much alike, that it is often impossible to distinguish the embryo of a sheep from that of a man, whose future genius may perhaps revolutionize the world” (p. 76).