“When a man undertakes to state the evidence of a theory, and gives us proofs that equally sustain an opposite theory, we naturally conclude that he does not know what he is talking about. This is very much Dr. Taylor’s predicament. In trying to contrast the evidence for evolution with the demonstrative proofs of the Copernican theory, he cites facts that are not only as good, but far better, to prove the truth of its antagonist, the Ptolemaic theory.” Our readers will probably ask how it is possible to prove that a thing is black by the very facts which prove, even better, that the thing is white? That certain facts may be insufficient to prove either the one or the other of two opposite theories every one will admit; but that facts which are good to prove the movement of the earth are even better to prove its immobility, is what Mr. Youmans alone has the privilege of understanding. Dr. Taylor, in his argument against Prof. Huxley, assumed the truth of the modern astronomical theory, and said that this theory was proved by facts presently occurring before our eyes; which is not the case with the hypothesis of evolution. But, as he did not mention in particular those facts which are considered to constitute the most irrefragable proof of the theory, his silence about them is interpreted by Mr. Youmans as an effect of ignorance. It is not our affair to defend Dr. Taylor; but we think that this interpretation is unfair. The reverend doctor was not writing a treatise of astronomy; he was simply stating a known doctrine, of which it was not his duty to make the demonstration. On the other hand, even if we admitted that the reverend doctor knows but little of astronomy, we do not see that this would weaken his argument; for, whether he knows much or nothing in this branch of science, it remains true that the Copernican theory is proved “by facts presently occurring before our eyes”—which is not the case with the hypothesis of evolution. It is to this truth that Mr. Youmans should have given his attention, if he desired “to win any distinction in the field of logic”; but his peculiar logic shrank from this duty, and prompted him to prefer a gratuitous denunciation of his opponent. Mr. Youmans pretends that Dr. Taylor “talks as if the Copernican theory is something that anybody can see by looking up in the sky.” Dr. Taylor’s words do not admit of such a nonsensical construction. The Copernican theory, he says, “rests on facts presently occurring before our eyes, and treated in the manner of mathematical precision.” This obviously means that the Copernican theory is based on both observation and calculation. Now, surely Mr. Youmans will not maintain that we can find mathematical formulas and make astronomical calculations by simply “looking up in the sky.”