Chapter 1

THE EVOLUTION OF LIFE--MECHANISM AND TELEOLOGY

Of duration in general--Unorganized bodies and abstract time--Organized bodies and real duration--Individuality and the process of growing old 1

Of transformism and the different ways of interpreting it--Radical mechanism and real duration: the relation of biology to physics and chemistry--Radical finalism and real duration: the relation of biology to philosophy 23

The quest of a criterion--Examination of the various theories with regard to a particular example--Darwin and insensible variation--De Vries and sudden variation--Eimer and orthogenesis--Neo-Lamarckism and the hereditability of acquired characters 59

Result of the inquiry--The _vital impetus_ 87