from one another may be found in the earliest Greek thinkers, just
as Pythagoras and Aristarchus anticipated the Copernican theory.
Aristotle gave the idea a philosophic statement which only the fuller
knowledge of our own time enables us to appreciate. He traced the
gradual progression in nature from the inorganic to the organic, and
among living things from the simpler to the higher forms. But his
knowledge of the facts was insufficient: the Greeks had no microscope,
and the dissecting knife was forbidden on the human subject. Then, as
these things were gradually added to science from the seventeenth
century onwards, and the record of the rocks gave the confirmation of
palaeontology, the whole realm of living nature was gradually unfolded
before us, every form connected both in function and in history with
every other, every organ fulfilling a necessary part, either now or in
the past, and growing and changing to gain a more perfect accord with
its environment. Such is the supreme conception which now dominates
biological science much as the Newtonian theory has dominated physics
for two hundred years; and it is idle to debate whether this new idea is
different in kind or only in degree from the great law of physics. It is
a general notion or law which brings together and explains myriads of
hitherto unrelated particulars; it has been established by observation
and experiment working on a previous hypothesis; it involves
measurement, as all accurate observation must, and it gives us an
increasing power of prediction. So far, therefore, we must class it with
the great mathematical laws and dissent from M. Bergson. But seeing that
the multitudinous facts far surpass our powers of complete colligation,
that much in the vital process is still obscure, that we are conscious
in ourselves of a power of shaping circumstances which we are inclined
in various degrees to attribute to other living things, so far we
recognize a profound difference between the laws of life and the laws of
physics, and pay our respects to M. Bergson and his allies of the
neo-vitalist school. Not for the first time in history we have to seek
the truth in the reconciliation, or at least the cohabitation, of
apparent contradictories.

To us who are concerned in tracing the progress of mankind as a whole,
and constantly find the roots of progress in the growth of the social
spirit, the development, that is, of unity of spirit and of action on a
wider an