334 THE HISTORY OF CREATION, 
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 4 priori Knowledge from 
Knowledge & 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 Pheno- 
mena.—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 Sonl.—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 con- 
vinced 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 examin- 
ation to refute at least the most important of these, and 
