rious classes of animals now upon the earth, no one can doubt, for the
different forms certainly show different degrees of mentality.
According to the evidence of those scientists who have studied the
remains of animals found in the earth's crust, there is a gradual
development of animal forms shown in successive epochs. In the very
oldest parts of the earth's crust, the remains of animal life found are
very simple. In later formations, the remains show an animal life more
complex. The highest forms of animals, the mammals, are found only in
the more recent formations. The remains of man are found only in the
latest formations.

Putting these two facts together--(1) that the higher types of mind are
found to-day only in the higher types of animals, and (2) that a gradual
development of animal forms is shown by the remains in the earth's
crust--the conclusion is forced upon us that mind has passed through
many stages of development from the appearance of life upon the earth to
the present time. Among the lower forms of animals to-day one sees
evidence of very simple minds. In amoebas, worms, insects, and fishes,
mind is very simple. In birds, it is higher. In mammals, it is higher
still. Among the highest mammals below man, we see manifestations of
mind somewhat like our own. These grades of mentality shown in the
animals of to-day represent the steps in the development of mind in the
animals of the past.

We cannot here go into the proof of the doctrine of development. For
this proof, the reader must be referred to zooelogy. One further point,
however, may be noted. If it is difficult for the reader to conceive of
the development of mind on the earth similar to the development of
animals in the past, let him think of the development of mind in the
individual. There can certainly be no doubt of the development of mind
in an individual human being. The infant, when born, shows little
manifestation of mentality; but as its body grows, its mind develops,
becoming more and more complex as the individual grows to maturity.

=The World as Dynamic.= The view of the world outlined above, and held by
all scientific men of the present time, may be termed the _dynamic_
view. Man formerly looked upon the world as static, a world where
everything was fixed and final. Each thing existed in itself and for
itself, and in large measure independent of all other things. We now
look upon things and events as related and dependent. Each th