minds and material things, as we know them,
are only manifestations, phenomena, and that they must be referred to
an ulterior "reality" or "substance." One may claim that they are
"aspects" of the one reality, which is neither matter nor mind.

These doctrines are different forms of _Monism_. In whatever else they
differ from one another, they agree in maintaining that the universe
does not contain two kinds of things fundamentally different. Out of
the duality of things as it seems to be revealed to the plain man they
try to make some kind of a unity.

35. MATERIALISM.--The first of the forms of monism above mentioned is
_Materialism_. It is not a doctrine to which the first impulse of the
plain man leads him at the present time. Even those who have done no
reading in philosophy have inherited many of their ways of looking at
things from the thinkers who lived in the ages past, and whose opinions
have become the common property of civilized men. For more than two
thousand years the world and the mind have been discussed, and it is
impossible for any of us to escape from the influence of those
discussions and to look at things with the primitive simplicity of the
wholly untutored.

But it was not always so. There was a time when men who were not
savages, but possessed great intellectual vigor and much cultivation,
found it easy and natural to be materialists. This I have spoken of
before (section 30), but it will repay us to take up again a little
more at length the clearest of the ancient forms of materialism, that
of the Atomists, and to see what may be said for and against it.

Democritus of Abdera taught that nothing exists except atoms and empty
space. The atoms, he maintained, differ from one another in size,
shape, and position. In other respects they are alike. They have
always been in motion. Perhaps he conceived of that motion as
originally a fall through space, but there seems to be uncertainty upon
this point. However, the atoms in motion collide with one another, and
these collisions result in mechanical combinations from which spring
into being world-systems.

According to this doctrine, nothing comes from nothing, and nothing can
become nonexistent. All the changes which have ever taken place in the
world are only changes in the position of material particles--they are
regroupings of atoms. We cannot directly perceive them to be such, for
our senses are too dull to make such fine obser