Chapter I: The Concepts of Evolution

Extension of the meaning of Darwinian concepts since
Darwin--Lewes on the Struggle for Existence as internal--The
mystery of "Variation" according to Darwin not a metaphysical
mystery, but one of the incompleteness of scientific
knowledge--Rolph's criticism of the Darwinian conception of the
Struggle for Existence criticised--General classification of the
theories of Evolution--Fechner's theory of the Tendency to
Stability--Petzoldt on Fechner--Petzoldt's concepts of Tendency
and Competition--Zoellner and Du Prel--Examination of the concept
of Absolute Stability, and of a full stability of the universe,
in the light of the question as to the finite or infinite
character of the material universe--Periodicity in
Organisms--Criticism of the concepts of Cause and
Effect--Criticism of Spencer's definition of Life--The concepts
of Heredity and Adaptation--The point of dispute with regard to
Variation--Darwin, Haeckel, and Eimer with regard to the
inheritance of individual acquirements--Criticisms of
Weismann--Habit in the life of the individual--Advantage of the
method pursued by Avenarius in the "Kritik der reinen
Erfahrung"--Lamarck on the relation of Use and Function--Darwin
on Habit and Instinct--Function and Tendency to
Function--Relation of organism and environment--Theory of a
special vital force--The relation of exercise to strength of
Tendency--The concepts of Cause and Effect as applied to
organism and environment--Relation of primary tendency to
later-evolved function--Form and Function--The mixture of types
in sexual propagation--Summary of conclusions 277-306