ed in respect either of the motion and
change which attend them, or the rationality which informs them. Life is
both effective and significant. Although neither of these ideas ever
wholly ceases to be animistic, they may nevertheless be applied quite
independently of one another. The one reduces the primitive animistic
world to the lower end of its scale, the other construes it in terms of
a purposive utility commensurable with that of human action. Now it is
with _mechanism_, the former of these diverging ways, that the
development of materialism is identified. For this philosophy a thing
need have no value to justify its existence, nor any acting intelligence
to which it may owe its origin. Its bulk and position are sufficient for
its being, and the operation of forces capable of integrating, dividing,
or moving it is sufficient for its derivation and history. In short,
there is no rhyme or reason at the heart of things, but only actual
matter distributed by sheer force. With this elimination of the element
of purposiveness from the hylozoistic world, the content and process of
nature are fitted to one another. Matter is that which is moved by
force, and force is the determining principle of the motions of matter.
Materialism is now definitely equipped with its fundamental conceptions.

[Sidenote: Materialism and Physical Science.]

Sect. 105. The central conceptions of materialism as a philosophical
theory differ from those employed in the physical sciences only in what
is demanded of them. The scientist reports upon physical phenomena
without accepting any further responsibility, while those who like
Lucretius maintain a physical metaphysics, must, like him, prove that
"the minute bodies of matter from everlasting continually uphold the sum
of things." But, though they employ them in their own way, materialists
and all other exponents of naturalism derive their central conceptions
from the physical sciences, and so reflect the historical development
through which these sciences have passed. To certain historical phases
of physical science, in so far as these bear directly upon the meaning
of naturalism, we now turn.

[Sidenote: The Development of the Conceptions of Physical Science. Space
and Matter.]

Sect. 106. From the earliest times down to the present day the
groundwork of materialism has most commonly been cast in the form of an
_atomic theory_. Democritus, the first system-builder of this school,
adopted