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 à 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 334

LIST OF WORKS REFERRED TO IN THE TEXT 371