There can be no doubt whatever that the habit of thought derived from
natural science is the greatest force in modern intellectual life, and
it must not be passed by heedlessly by any one concerned with the
spiritual interests of humanity. But it is none the less true that the
way in which it sets about satisfying spiritual needs is superficial
and shallow. If this were the right way, the outlook would indeed be
dreary. Would it not be depressing to be obliged to agree with those
who say: "Thought is a form of force. We walk by means of the same
force by which we think. Man is an organism which transforms various
forms of force into thought-force, an organism the activity of which
we maintain by what we call 'food,' and with which we produce what we
call 'thought.' What a marvellous chemical process it is which could
change a certain quantity of food into the divine tragedy of Hamlet."
This is quoted from a pamphlet of Robert G. Ingersoll, bearing the
title, _Modern Twilight of the Gods_. It matters little if such
thoughts find but scanty acceptance in the outside world. The point is
that innumerable people find themselves compelled by the system of
natural science to take up with regard to world-processes an attitude
in conformity with the above, even when they think they are not doing
so.

It would certainly be a dreary outlook if natural science itself
compelled us to accept the creed proclaimed by many of its modern
prophets. Most dreary of all for one who has gained, from the content
of natural science, the conviction that in its own sphere its mode of
thought holds good and its methods are unassailable. For he is driven
to make the admission that, however much people may dispute about
individual questions, though volume after volume may be written, and
thousands of observations accumulated about the struggle for existence
and its insignificance, about the omnipotence or powerlessness of
natural selection, natural science itself is moving in a direction
which, within certain limits, must find acceptance in an
ever-increasing degree.

But are the demands made by natural science really such as they are
described by some of its representatives? That they are not so is
proved by the method employed by these representatives themselves. The
method they use in their own sphere is not such as is often described,
and claimed for other spheres of thought. Would Darwin and Ernst
Haeckel ever have made their great discov