ons and mutations, only the
last-named being heritable, and therefore of importance for the origin
of new species. But the existence of variations is not only of interest
for the problem of the origin of species; it has also a more general
interest. An individual does not lose its importance for knowledge,
because its qualities are not heritable. On the contrary, in higher
beings at least, individual peculiarities will become more and more
independent objects of interest. Knowledge takes account of the
biographies not only of species, but also of individuals: it seeks to
find the law of development of the single individual. (The new science
of Ecology occupies an intermediate position between the biography of
species and the biography of individuals. Compare "Congress of Arts and
Science", St Louis, Vol. V. 1906 (the Reports of Drude and Robinson)
and the work of my colleague E. Warming.) As Leibniz said long ago,
individuality consists in the law of the changes of a being. "La loi du
changement fait l'individualite de chaque substance." Here is a world
which is almost new for science, which till now has mainly occupied
itself with general laws and forms. But these are ultimately only means
to understand the individual phenomena, in whose nature and history
a manifold of laws and forms always cooperate. The importance of this
remark will appear in the sequel.

V.

To many people the Darwinian theory of natural selection or struggle
for existence seemed to change the whole conception of life, and
particularly all the conditions on which the validity of ethical ideas
depends. If only that has persistence which can be adapted to a given
condition, what will then be the fate of our ideals, of our standards
of good and evil? Blind force seems to reign, and the only thing that
counts seems to be the most heedless use of power. Darwinism, it was
said, has proclaimed brutality. No other difference seems permanent save
that between the sound, powerful and happy on the one side, the sick,
feeble and unhappy on the other; and every attempt to alleviate this
difference seems to lead to general enervation. Some of those who
interpreted Darwinism in this manner felt an aesthetic delight in
contemplating the heedlessness and energy of the great struggle for
existence and anticipated the realisation of a higher human type as the
outcome of it: so Nietzsche and his followers. Others recognising the
same consequences in Darwinism regar