With regard to the prolificness of half-breeds, I have already mentioned such facts as might have served to dispel the learned writer's doubts, had he been acquainted with them. In reference to the other, more serious, obstacle to his admission of the plurality of origins, he himself intimates (p. 339) that the authority of this interpretation might, perhaps, be questioned without transgressing the limits imposed by the church. Believing this view to be correct, I shall venture on a few remarks upon this last scruple of the author, which is shared by many investigators of this interesting subject. "The strict rule of scientific scrutiny," says the most learned and formidable opponent in the adversary's camp,[215] "exacts, according to modern philosophers, in matters of inductive reasoning, an exclusive homage. It requires that we should close our eyes against all presumptive and exterior evidence, and _abstract our minds from all considerations not derived from the matters of fact which bear immediately on the question_. The maxim we have to follow in such controversies is 'fiat justitia, ruat coelum.' _In fact, what is actually true, it is always desirous to know, whatever consequences may arise from its admission._" To this sentiment I cheerfully subscribe: it has always been my maxim. Yet I find it necessary, in treating of this subject, to touch on its _biblical_ connections, for although we have great reason to rejoice at the improved tone of toleration, or even liberality which prevails in this country, the day has not come when science can be severed from theology, and the student of nature can calmly follow her truths, no matter whither they may lead. What a mortifying picture do we behold in the histories of astronomy, geology, chronology, cosmogony, geographical distribution of animals, &c.; they have been compelled to fight their way, step by step, through human passion and prejudice, from their supposed contradiction to Holy Writ. But science has been vindicated--their great truths have been established, and the Bible stands as firmly as it did before. The last great struggle between science and theology is the one we are now engaged in--the _natural history of man_--it has now, for the first time, a fair hearing before Christendom, and all any question should ask is "_daylight and fair play_." The Bible should not be regarded as a text-book of natural history. On the contrary, it must be admitted that none of the writers of the Old or New Testament give the slightest evidence of knowledge in any department of science beyond that of their profane contemporaries; and we hold that the natural history of man is a department of science which should be placed upon the same footing with others, and its facts dispassionately investigated. What we require for our guidance in this world is truth, and the history of science shows how long it has been stifled by bigotry and error.