some
measure of comfort from the recollection that during the few thousand
years through which we can trace political history in the past, man,
without changing his nature, has made enormous improvements in his
polity, and that those improvements have often been the result of new
moral ideals formed under the influence of new knowledge.

The ultimate and wider effect on our conduct of any increase in our
knowledge may indeed be very different from, and more important than,
its immediate and narrower effect. We each of us live our lives in a
pictured universe, of which only a small part is contributed by our own
observation and memory, and by far the greater part by what we have
learnt from others. The changes in that mental picture of our
environment made for instance by the discovery of America, or the
ascertainment of the true movements of the nearer heavenly bodies,
exercised an influence on men's general conception of their place in the
universe, which proved ultimately to be more important than their
immediate effect in stimulating explorers and improving the art of
navigation. But none of the changes of outlook in the past have
approached in their extent and significance those which have been in
progress during the last fifty years, the new history of man and his
surroundings, stretching back through hitherto unthought-of ages, the
substitution of an illimitable vista of ever changing worlds for the
imagined perfection of the ordered heavens, and above all the intrusion
of science into the most intimate regions of ourselves. The effects of
such changes often come, it is true, more slowly than we hope. I was
talking not long ago to one of the ablest of those who were beginning
their intellectual life when Darwin published the _Origin of Species_.
He told me how he and his philosopher brother expected that at once all
things should become new, and how unwillingly as the years went on they
had accepted their disappointment. But though slow, they are
far-reaching.

To myself it seems that the most important political result of the vast
range of new knowledge started by Darwin's work may prove to be the
extension of the idea of conduct so as to include the control of mental
processes of which at present most men are either unconscious or
unobservant. The limits of our conscious conduct are fixed by the limits
of our self-knowledge. Before men knew anger as something separable from
the self that knew it, and before th