e mistakes were and
how tenaciously they were held to, how strenuously defended. Most of
all it would be of value to note that the false inductions which
have everywhere hampered the progress of science have been, from the
stand-point of the generation in which they originated, for the most
part logical inductions. We have seen that the Ptolemaic scheme of the
universe, false though it was in its very essentials, yet explained
in what may be termed a thoroughly scientific fashion the observed
phenomena. It is one way of expressing a fact to say that the sun moves
across the heavens from the eastern to the western horizon; and for most
practical purposes this assumption answers perfectly. It is only when
we endeavor to extend the range of theoretical astronomy, and to gain a
correct conception of the mechanism of the universe as a whole, that
the essentially faulty character of the geocentric conception becomes
apparent.

And so it is in many another field; the false generalizations and hasty
inductions serve a temporary purpose. Our only quarrel with them is that
they tend through a sort of inertia to go forever unchanged. It requires
a powerful thrust to divert the aggregate mind of our race from a given
course, nor is the effect of a new impulse immediately appreciable; that
is why the masses of the people always lag a generation or two
behind the advanced thinkers. A few receptive minds, cognizant of new
observations that refute an old generalization, accept new laws, and,
from the vantage-ground thus gained, reach out after yet other truths.
But, for the most part, the new laws thus accepted by the leaders remain
unknown to the people at large for at least one or two generations. It
required about a century for the heliocentric doctrine of Copernicus to
begin to make its way.

In this age of steam and electricity, progress is more rapid, and the
greatest scientific conception of the nineteenth century, the Darwinian
theory, may be said to have made something that approaches an absolute
conquest within less than half a century. This seems a marvellously
sudden conquest, but it must be understood that it is only the crude and
more tangible bearings of the theory that have thus made their way. The
remoter consequences of the theory are not even suspected by the great
majority of those who call themselves Darwinians to-day. It will require
at least another century for these ideas to produce their full effect.
Then, in