PAST, PRESENT, AND FUTURE 451

implements, tools, machinery, sufficient to upset and revolu-
tionise the entire economy of human civilisation. Some of
these inventions we have already referred to in the course
of our survey; a little more may be said about them here.

Life in the ancient and even medieval times was simpler,
in that its organisation was less intricate than it is now. With
increased complexity has also come better organising ability
which has made man more powerful for construction no less
than destruction. The secret of this power, for good and
evil, is summed up in the magical word 'Science.1 It is
exercising over modern man the same influence that magic
did over the ancient and medieval. Having its roots deep
down in the Past, Science has come into its very own in
our times.

In studying the significance of this most vital force in the
moctern world we must distinguish between Pure science
and Applied science. Reserving the former for later com-
ment, we shall first deal with the latter; for Pure science
concerns the intellectual few, while Applied science has affect-
ed the lives of all. Applied science is Science in relation
to practical life. It is the ' science of tools' or * technology'
which began with the inventions of the palaeolithic man and.
still continues to transform the earth and human life in a
most wonderful manner. Its first marvel was revealed in
the mechanical inventions devised by Heron, the Alexandrian
mathematician of the first century A.D., and its potentialities
disclosed by the genius of Leonardo da Vinci in the fifteenth
century A.D. The versatility of Leonardo has been referred
to before. 'Architect, sculptor, painter and engineer,' as
Mr. Marvin has said, * no one exhibits more dearly in his
own person the intimate connexion between actual construct-
ive work and the imaginative use of the mind. He devised
himself some good dozen of inventions which have since