{ | | | { South Europe (about 600 millions) { | | | { | | | | | | { In all parts of the world, 13. HYBRIDS | 11 | Pr | Pl { but predominating in America OF THE | | | { and Asia SPECIES | | | --------------------+--------+ | TOTAL 1350 CHAPTER XXIV. OBJECTIONS AGAINST, AND PROOFS OF THE TRUTH OF, THE THEORY OF DESCENT. Objections to the Doctrine of Filiation.—Objections of Faith and Reason.—Immeasurable Length of the Geological Periods.—Transition Forms between Kindred Species.—Dependence of Stability of Form on Inheritance, and of the Variability of Form on Adaptation.—Origin of very complicated Arrangement of Organisation.—Gradual Development of Instincts and Mental Activities.—Origin of a priori Knowledge from Knowledge a posteriori.—The Knowledge requisite for the Correct Understanding of the Doctrine of Filiation.—Necessary Interaction between Empiricism and Philosophy.—Proofs of the Theory of Descent.—Inner Causal Connection between all the Biological Series of Phenomena.—The Direct Proof of the Theory of Selection.—Relation of the Theory of Descent to Anthropology.—Proofs of the Animal Origin of Man.—The Pithecoid Theory as an Inseparable Part of the Theory of Descent.—Induction and Deduction.—Gradual Development of the Human Mind.—Body and Mind.—Human Soul and Animal Soul.—A Glance at the Future. If in these chapters I may hope to have made the Theory of Descent seem more or less probable, and to have even convinced some of my readers of its unassailable truth, yet I am by no means unconscious that, to most of them, during the perusal of my explanations, a number of objections more or less well founded must have occurred. Hence it seems absolutely necessary at the conclusion of our examination to refute at least the most important of these, and at the same time, on the other hand, once more to set forth the convincing arguments which bear testimony to the truth of the theory of development.